Why are old spectrum analyzers so expensive? - Page 1
Forum section: electronics / testgear

author: Dan Moos
author_rank: Frequent Contributor
timestamp: December 14, 2016, 05:04:11 am
content: How come the price gap between an old crt analyzer on eBay and a new Rigol our Siglent lower end signal analyzer is so narrow? Old crt scopes of good quality are dirt cheap, but analyzers of the same vintage seem so expensive that I don't see the point of not getting a modern one. I am beginning to dabble in RF stuff, and thought an old Tek or Hp analyzer in the 9k to maybe 2G bandwidth range would be nice, but a trip to eBay killed that plan.So my question is, why are the old ones still so expensive? Are the entry level Rigol and Siglents deficient in some way that I'm missing such that it's better to spend only a 4 or 5 hundred less for one from the eighties?I do get why analyzers are more spendy than scopes I guess. Less market, and more complex analog electronics I presume.

author: razberik
author_rank: Frequent Contributor
timestamp: December 14, 2016, 07:49:33 am
content: I do really think that EEVblog forum is influencing this. EEVblog brought many people to fields of interest which were never interested in before. Some instruments were cheap and there were many of them, but not anymore.And then there is also a dozen of freaks who dont know what is the use of some instruments but they read here it is a good piece of equipment. So they bought them, but dont really know how to use it instead.

author: neil t
author_rank: Regular Contributor
timestamp: December 14, 2016, 07:58:35 am
content: It seems to me that the ratio of oscilloscopes to spectrum analysers in the second hand market might have something to do with therarefied like price tag , ive been looking for a number of years now for a good affordable SA and will probably end up coughing up thatsort of cash for something with a warranty, ie digital SA, but you are not alone in your observations (disappointment), keep the hope aliveperhaps someone will flood the market with the equipment we seek one day?.

author: cat87
author_rank: Regular Contributor
timestamp: December 14, 2016, 08:07:46 am
content: It' s indeed sad to see that an old HP SA from the 90's is worth just as much as a new Rigol / Siglent SA but this is true for a lot of equipment sold on eBay.Test gear on eBay has always been expensive. Individuals that sell such gear ask for them some idiotic price that has nothing to do what it should be worth. This always rattles my cage.I got some things off of eBay, but only after months of searching. The only way you could get some cheap-ish stuff is to look at some users on eBay that sell equipment in bulk form i.e. they get it from some company that closed or that removed their old inventory and practically gave away the stuff.That's how I got my HP 3478A for example.

author: nctnico
author_rank: Super Contributor
timestamp: December 14, 2016, 08:23:45 am
content: Look at Advantest. You can buy an R3131 (3GHz monochrome display) for much less than $1000 and every now and then higher end models appear on the market as well for reasonable prices. A couple of months ago I scored a really nice one for less than $2000 (13GHz, PC based, touch screen).

author: DaJMasta
author_rank: Super Contributor
timestamp: December 14, 2016, 08:25:26 am
content: I think part of it is also how recently the cheap analyzers started coming around, it's only recently that they were an alternative, so those interested in one in previous years have kept the demand up even though there are affordable alternatives.Some of it is also the specs and name recognition. Frontends have improved a lot less than processing tech in the last 10-20 years, so even if an analyzer from the 90s has a tenth or less of the update rate, less memory, less math and statistic functionality, less interconnectivity, etc - it probably still has a lot of specs that are comparable or better than the current lower end units - so for people who don't value the extra processing power or features (if they just don't know or if they're used to working with equipment that's not that fast to update), the old gear may still look more appealing. Heck, there's plenty of people that still snub their nose at Rigol because they're made in China and don't cost a fortune...

author: technogeeky
author_rank: Frequent Contributor
timestamp: December 14, 2016, 09:11:10 am
content: I think people here are wildly over thinking the answer to root of your question.My (essentially guess):They are so expensive because they were (and continue to be) much more difficult to to engineer:They are (always? is this a law? I wonder...) more difficult to engineer an oscilloscope of equivalent bandwidth and sampling rate; e.g.they were way more expensive back thenBeyond that, one wants a spectrum analyzer that hassignificantly higherbandwidth still than whatever frequency is of interest, to be able to see harmonic content and modulated signals and so on...They usually have lots of mixersindependently useful,valuableand often fragile (in the power handling sense)other things inside of them likemixers,attenuators, andRF switches. These are often valued on the same order of magnitude as the device these days. Once removed and resold, you remove one of these devices from the market.And lots of those analyzers are still world-class. Remember that they have to have not only (more) bandwidth and sampling rate, but they also pretty much always have hugedynamic range.

author: Towger
author_rank: Super Contributor
timestamp: December 14, 2016, 10:19:34 am
content: Just to add to above. An SA used to be much more expensive than a scope. In real terms, as least here you were looking at the price of a good car or even a house. Roll forward 20~30 years some people still expect big money old what is now an old clunker, based on what it was originality worth.

author: Fungus
author_rank: Super Contributor
timestamp: December 14, 2016, 10:24:13 am
content: Quote from: Dan Moos on December 14, 2016, 05:04:11 amQuote from: cat87 on December 14, 2016, 08:07:46 amThis. eBay is a terrible place to buy test gear. You have to be really lucky to get something reasonable.(or very patient, something worthwhile does come along every few months or so...)

author: Kjelt
author_rank: Super Contributor
timestamp: December 14, 2016, 10:40:42 am
content: Here in the Netherlands, HP/Keysight etc. dealers gave big discounts (think 30% extra) on a new SA if you turned in the old one.I talked to that HP guy in 1995 because I was interested in purchasing the old one from them, wanted to know how much it cost.It was kind of a shock, HP bought the old SA and then destroyed them, and the only reason was that they did not want a 2nd hand market in SA's to protect the market for new SA's.If a small business needed one they could rent it or buy a brand new one, no second hand market, that is probably why today there are relatively little of them left, at least here.Not sure if that was the policy everywhere.

author: woodchips
author_rank: Frequent Contributor
timestamp: December 14, 2016, 10:47:23 am
content: Just bought an HP140 with the 1250MHz plug in. Last used from the stickers in mid 90s, powered on and after an hour it was running just ok, lots of caps needed reforming. This dates from the 70's, from chip dates mine was made in 1982. These are good bits of kit, not a processor to be seen, just analogue. But of course that means it is of zero interest to the all digital colour display crowd, just as well, cost me £120, the 18GHz plug in cost £80 but yet to try that.In another thread apparently chips die after a few years, perhaps not.

author: HighVoltage
author_rank: Super Contributor
timestamp: December 14, 2016, 11:34:57 am
content: I have an old 12 GHz HP SA and a modern RigolThe HP was about Euro 7000, when I bought it in 2009 and it was worth every penny of it.These days with the Rigol being so cheap, I would probably not buy an HP anymore.But even now, I am using both of them.

author: Bicurico
author_rank: Super Contributor
timestamp: December 14, 2016, 11:50:02 am
content: Hi,I have been looking for a second hand spectrum analyser for YEARS. Much before I even knew EEVblog existed. And I have thought about this question a lot.These devices have always been very expensive and will continue to be.Here is my reasoning:1) Professional high-end grade spectrum analysers ("lab-grade") cost a fortune new. Fortune in like as expensive as a premium car or a cheap house! A fully equipped R&S spectrum analyser/TV analyser has shown up SECOND HAND, but as new with warranty, with a starting price of 65.000 Euro (I know because I constantly search eBay for these devices)! How much did it cost brand new at R&S? No idea... 100.000 Euro? This is just to get the right mind set, when we are talking about expensive...2) Spectrum analysers are technically complicated. An analogue scope is ridiculously simple, considering the theoretical way it works. Look at a sweep spectrum analyser and what's inside the box: it is magnitudes more complex. And it uses a lot of hard to get components. And there was a LOT more engineering to it. If you have a 10 year old SSA, where one component breaks, it can be economically viable to purchase a broken one for imagine 3.000 Euro, just to extract that single component to do the repair.3) Spectrum analysers are ONLY expensive to amateurs. If you work in a company that NEEDS a spectrum analyser, then their price is just their price: the end product price this company manufactures will reflect that investment. Analogy: a CMM (coordinate measuring machine) can easily cost 100.000 Euro. Even second hand it will be >20.000 Euro after decades. There are companies doing retrofits on these CMM's for a lot of money. Yet, you don't see people complaining on forums how expensive CMM's are. That is because probably no amateur would consider having such a beast in the garage! Just because a spectrum analyser has a small size and can be tolerated by the wife, doesn't change the fact that it is a masterpiece of HF engineering and a metrology device, that happens to be much more complex than most other machines (including CMM's).4) There is a HUGE demand for spectrum analysers: many amateurs want them for the most distinct applications: EMI measurements on electronic designs, DX in radio, TV and SAT bands, antenna tuning, amateur radio (much better to see the whole spectrum instead of scanning pre-programmed frequencies)... These amateurs come from different background and have a different perception of how much they are willing to spend on a second hand spectrum analyser. Example: an amateur radio enthusiast has easily spent a few thousand Euro in some Yaesu, Icom, etc. transciever - amateur radio is expensive! Spending 2.000 Euro on a spectrum analyser that will show him the whole spectrum at a glance is totally worth it! Take the other end of scale: the arduino hacker who buys sensors from China at sub-Euro prices will be shocked to see the same spectrum analyser is sold for 2.000 Euro! But there is a long way to satisfy the demand of those willing to fork out thousands of Euro on a spectrum analyser, so the arduino hacker is at the end of the queue...5) The new cheaper SSA: Rigol and Siglent. They may change the future of spectrum analysis! Instead of going to a lab to have something measured on a 100.000 Euro spectrum analyser, you can now buy one for 1500 Euro new with warranty! This opens doors even to amateurs! No need to discuss if they are as good as the lab grade devices - they are not. BUT: They are good enough for most applications and when you finally do go to the lab, you just do it, so you get a traceable measurement certificate - you already know what to expect. Many companies can now own their own inhouse cheap Rigol/Siglent spectrum analyser. It will pay for itself in reduced number of visits to the lab.6) Even cheaper: look at the chinese SMA Simple Spectrum Analyser clones! I am pretty amazed what I could do with them using my software. And now we are taling about less than 100 Euro!Conclusion:1) Lab grade spectrum analysers will always be "expensive" for amateurs.2) Lab grade spectrum analysers are valuable for spare parts on devices still in use and in this case, price doesn't matter.3) Some brands have collector value: I would LOVE to own second hand R&S equipment, just for the brand sake! I would love to own a premium SA from HP/Agilent from the 80ies or 90ies. For not special reason, other to have a museum piece that was state of the art technology. To me, this is as atractive as owning a signed Andy Warhol litography. It's collectors items. They carry value. It is fun restoring them.4) Even those who know nothing about HP, Agilent, R&S, etc. will figure out they sell for premium prices after a 5 minute Google search.Regards,Vitor

author: joeqsmith
author_rank: Super Contributor
timestamp: December 14, 2016, 12:00:35 pm
content: What's a used 24GHz oscilloscope going for now days? I gave away my old HP 24GHz SA over the summer. Checked eBay to get some idea and prices first. Many of the SAs I looked at seemed to have a fair price.

author: Fraser
author_rank: Super Contributor
timestamp: December 14, 2016, 12:17:54 pm
content: From my life experience, a spectrum analyser is a far more specialist test equipment than most oscilloscopes and a rarer commodity in the market place. My R4131D units cost GBP 15K when new in the late 1990,s, but some SA's cost far more than that. Names like HP And R&S always cost far more when new or used.Are the older SA's worth the used prices ? Well I sell R4131D 3.5GHz SA's for between GBP 700 to GBP 1000. I think they are worth that due to being a great user friendly light weight analyser in great condition. The purchasers have certainly been pleased with them. Some huge HP Analysers weigh a Tonne and so are far less practical in a hobby environment. Ask yourself why they are so large and heavy though. Some have very sophisticated and complex RF sections that provide top of the line RF performance with superb long term stability. Such may not be the case with modern 'cheap' SA offerings.I own several SA's and can state that you often get what you pay for. Expecting a modern cheap SA to have specifications equally to an older analyser that cost ten times as much in 2001 may not be realistic as microprocessor and software advances such as SDR techniques are not the whole story with a quality SA. In a radio receiver you can tolerate some 'issues' with Dynamic range and spurii in the RF front end Such issues are not good news in a piece of lab equipment that you need to trust. WYSIWYG is needed as you need to see issues in a designs performance and not be trying to spot problems amongst SA intermodulation spurii, oscillator breakthrough and poor dynamic range in the DSP stages.I would happily buy a modern cheap SA but it needs to meet my frequency coverage and sweep time needs and I would have to take account of any compromises in the design that enabled it to be cheap.A classic case of horses for courses. RF engineers like myself will always pay a higher price for equipment that has good specifications that may be trusted, that is well designed and has stood the test of time.On the down side..... buyers of older SA's need to be aware that they can suffer from the following.....Memory battery failure that can effect option activationCapacitor ageing in the PSU especially.Screen burn on CRT modelsOscillator ageing and drift in some modelsPrevious owner damage and repairs .... always a risk.Sometimes large and heavy plus fragile, so risky to ship.Some older SA's were not very good when new, even worse when old !Whilst service manuals are sometimes available, used SA's can be a challenging repair if they fail. They can become an expensive paperweight !My advice is to assess your own true needs in terms of budget and required performance. If a modern 'cheap' SA fits your needs you should seriously consider buying it. If you need better performance and cannot afford the better SA's at new prices, consider an SA from the used marketplace but bear in mind my warning of issues that can be present. I personally would not buy anything earlier than the mid 1990's no matter what brand.Fraser

author: Fraser
author_rank: Super Contributor
timestamp: December 14, 2016, 12:33:43 pm
content: Further to my last.......When I wanted a cheap but highly portable spectrum analyser for some field work, I bought various CATV test meters / analysers that also contained a spectrum analyser function. These were cheap to buy and provided an SA that covered 25MHz to 1000MHz with RBW options and both frequency and amplitude measurement. I have a pile of Waverek SDA4040D units and many other CATV Analysers, even units from HP and Tektronix. Some even contain tracking generators for filter and amplifier testing. They met my needs at the time and I thought outside the box to get something affordable. They cost less than GBP 100 each as CATV installers were upgrading to wholly digital networks.Fraser

author: joeqsmith
author_rank: Super Contributor
timestamp: December 14, 2016, 02:05:08 pm
content: Quote from: Fraser on December 14, 2016, 12:17:54 pmDon't forget the mixers and attenuators by the people that thought they could just plug their HAM radios right into the inputs....

author: Bicurico
author_rank: Super Contributor
timestamp: December 14, 2016, 02:30:55 pm
content: I have experience with TV field meters (I own a collection of 20+ field meter, some pretty recent) and yes they often feature a spectrum analyser functionality.Pros:- Relatively cheap- Good input protection- Can drive satellite LNB- Easy to use- Demodulator + MPEGCons:- Large, non-configurable, RBW on most models- Limited SPAN selection- Some are SLOWWWWW- Reduced precision- Lack many spectrum analyser functionalityPrices can vary from bargain (Emitor Satlook Digital NIT) to pretty expensive.I would recommend a TV field meter as a spectrum analyser replacement mainly for people into TV applications.Regards,Vitor

author: Fraser
author_rank: Super Contributor
timestamp: December 14, 2016, 05:17:43 pm
content: @Bicurico,I agree, CCTV analyzers are not deigned to be a substitute for a lab spectrum analyzer.They do, however, offer an affordable option to those who cannot afford a full spectrum analyzer and the RF ingress/egress functions can be quite powerful. Good units may be manually set to a centre frequency rather than having to be set to a TV channel. As you state, the span can be limited to 50MHz or so. As for the trace update speed, yes this can be slow as these units are basically a radio receiver with a synthesizer being swept through the required range. Smaller spans often provide faster screen updates.As I said, I was thinking outside the box and my first Wavetek SDA4040D cost me only GBP50. It did what was needed of it on an antenna test range and I was even able to use it for setting up TV antennasThe Wavetek CLI 1750 that I have comes with a tracking generator that the CLI 1750 controls via a serial cable. It can plot filter and amplifier responses before displaying them on the screen, downloading to a PC, or printing to a 4" thermal printer that I also have. Nice bit of versatile kit really.I have quite a collection of TV field strength meters as well. I shall have to start a new thread and show them for fellow techs who like such kitI attach pictures of three of my CATV meters, plus datasheets for the Wavetek's.Fraser

author: Bud
author_rank: Super Contributor
timestamp: December 14, 2016, 05:32:07 pm
content: A simple answer is people value old SAs higher than cheap digital junk referenced in this thread.

author: Bicurico
author_rank: Super Contributor
timestamp: December 16, 2016, 11:24:57 pm
content: @Fraser: that is a nice collection you have. I see you rival me with your collection. But where on earth did you hey turn that cheap?Regards,Vitor

author: G0HZU
author_rank: Super Contributor
timestamp: December 17, 2016, 12:50:27 am
content: I would group the various 'affordable' spectrum analysers (new and old) as below.Top Group: These are the classic 'elite' analysers from the 1980s and 1990s and include the classic HP8566 and HP8568 and the HP8560/1/2/3. Also the Advantest TR4172 if you can live with the huge size/weight and the ugly user interface and some of its quirks. All of these can be purchased for under £2000 today and some for well under £1000 if you are brave. The Advantest is often very cheap. These are all fabulous analysers and can be used even today for serious RF design in a decent RF lab. But they lack the benefits that come with a modern/wide digital IF. I still think that they offer amazing value for money if you need the performance they offer in terms of dynamic range, measurement uncertainty, phase noise etc etc.Mid Group: These are the classic mid range analysers of yesteryear including field services analysers like the (truly awful) HP859x range. Also various mid range analysers from Advantest, Anritsu and maybe Tektronix. These are usually overpriced in my opinion and I don't have much to say about them except avoid them all unless you are desperate and the price is right. None of these analysers would get into our labs at work because the performance is way below the elite class of analyser.Low Group: These are the very old analysers from the 1970s and also I'll include the various (fairly modern) phone/comms 'test set' boxes that include a built in spectrum analyser along with a sig gen and power meter etc. These are OK if you want something to service basic CBs or ham radio gear but they are basically shite if you want/expect decent RF performance. I would normally avoid any of the mid range analysers but these low end analysers and test sets are often much worse.New Group: I'll ignore all the modern little handheld units with a limited display as these are only useful for very casual/portable use. You either need this size/portability or you don't. So that leaves the various offerings from Rigol and Siglent. The Rigol 815 was a sensation when it first arrived because it offered reasonable RF performance with a modern digital IF in a unit the size of a portable scope for just over £1000. Amazing and highly disruptive... But it looks like it has been eclipsed by the new Siglent. There are other more expensive models from Rigol and Siglent but these are more suited to small business use. I think that I would much rather have the Siglent than any of the mid or low range analysers above. This is because of the modern digital IF, the decent display and all the modern toys/tools it offers. The RF performance will be fairly mediocre but some things it can do will be extremely useful (and accurate) because of its modern digital IF. So this gives it a modern edge.In my opinion there are only two valid groups (unless you are desperate in terms of cash and bench space). You either 'need' the performance of an elite analyser from the 80s and you live with the risks with reliability and put up with the noise and huge size/weight. Or the alternative is the Siglent or maybe the Rigol 815 if you can get a cheap deal and can live with the various compromises wrt RF performance. The Rigol/Siglent analysers won't have the RF performance (in the RF downconverter) compared to the old elite analysers but you do get all the toys associated with a modern digital IF and the big display on the Siglent looks very nice indeed.At the moment I'm mostly using a 22GHz HP8566B analyser and an Agilent E4406A signal analyser (14 bit digital IF version) on my bench. These cost me a combined total of about £1500. One day I'll upgrade to an Agilent PSA and maybe even a PXA but that day is some way off yet.

author: nctnico
author_rank: Super Contributor
timestamp: December 17, 2016, 01:39:05 am
content: Quote from: G0HZU on December 17, 2016, 12:50:27 amAdd the 2000s to the top group too! After all a machine made in 2000 is looking at it's 20th birthday real soon. A couple of months ago I got an Advantest SA for less than $2k with an 800x600 TFT color touch screen, digital IF, 10MHz RBW, USB storage, network, etc.

author: joeqsmith
author_rank: Super Contributor
timestamp: December 17, 2016, 02:13:15 am
content: Quote from: G0HZU on December 17, 2016, 12:50:27 amBut I like my little handheld headless SA.

author: vk6zgo
author_rank: Super Contributor
timestamp: December 17, 2016, 02:19:19 am
content: Quote from: Bud on December 14, 2016, 05:32:07 pmNot only "cheap" digital junk--my last work had a quite nice IFR SA which had one "Achilles heel".We had some PLLs which were told what frequency they should be on by parallel data from a PIC.The PLLs would become unlocked & go from the required 433 (or so)MHz to 470MHz,which seemed to be a "default" frequency.What had us concerned more than the overall change was that the SA displayed a number of "spurious signals" between the correct & incorrect frequency.We bought a little "El Cheapo" Atten analog SA to show us if one of the PLLs was unlocked in service.On turning the equipment on,we were treated to the sight of one of the PLLs changing frequency smoothly between the required & default frequencies,without any sign of spurii.It turns out that the IFR"s sample rate was too slow to display the change in frequency,& insteaddisplayed each sample as a discrete signal---duhhh!!!The problem with the PLL turned out to be poor connections between the PIC & PLL.Without the Atten,we would probably still be looking for those "sprogs"!

author: hendorog
author_rank: Super Contributor
timestamp: December 17, 2016, 04:10:43 am
content: Quote from: joeqsmith on December 17, 2016, 02:13:15 amAnd worth noting that your BB60C can do many things the old stuff can't - stuff which is relevant nowadays.I'm very happy with my SA124B too. The bandwidth limitations of the Rigol and Siglent would have ruled them out for me if they were around then. The USB devices often get overlooked because they don't have a screen - they are a bargain for those who can see past that

author: joeqsmith
author_rank: Super Contributor
timestamp: December 17, 2016, 05:18:10 pm
content: Quote from: hendorog on December 17, 2016, 04:10:43 amI really don't know what Siglent and Rigol offers. The person posting all the Siglent data stopped once I started posting the QAM demodulation. I would guess that most of the systems could decode that Extech meter I showed. I played with the HDSDR software which is really slick. I am not sure why (pure luck?) but that software has yet to hang with the BB60C. I don't think I have ever seen it hang running swept mode.The whole headless thing has not really bothered me. Often I run my equipment from a PC anyway and having the hooks for custom software is a must. With the BB60C, using the USB3, I can move a fair amount of data fairly quickly into the PC. I tried some tests without using the decimation at the highest sample rates and was able to keep up with LabVIEW.Show us the Siglents and Rigols doing some basic demodulation.Here's the BB60C decoding a very basic 2FSK, 2400 BAUD with a 915MHz carrier.https://youtu.be/f1UtLpSZ2W0?t=1756

author: G0HZU
author_rank: Super Contributor
timestamp: December 17, 2016, 05:43:41 pm
content: Quote from: joeqsmith on December 17, 2016, 02:13:15 amBy handheld I mean the new and cheap spectrum analysers with a built in (limited) display that can be picked up and viewed as you walk around a test site. Think more in terms of the RF Explorer than the Signalhound USB + PC products.The Signalhound USB based stuff probably deserves its own category along with the Tek RSA306. They can't compete with the best of the old school analysers (or even the mid range analysers) for downconverter performance but they do have that huge real time bandwidth in the BB60C and all of the toys associated with the post processing in the PC. Powerful stuff indeed. The original SH44 with its narrow real time BW would be a good choice for radio hams and maybe also for EMC work but the unconventional design in terms of how it achieves its image/spurious rejection means that it will have a few holes in its performance/integrity as a spectrum analyser. Probably fine for casual use but risky for some types of use.

author: joeqsmith
author_rank: Super Contributor
timestamp: December 17, 2016, 06:48:27 pm
content: I rate my old SAs at the bottom of the heap, or maybe floor sweepings if there is a category for that. I don't think there is anything that my old Tektronix SA does better than my Signal Hound except using more power and shelf space. The handhelds you mention may even have better specs. The last time I used the HP8569A was when we were playing with those el cheapo oscillators.https://www.eevblog.com/forum/projects/el-cheapo-oscillator/

author: Fraser
author_rank: Super Contributor
timestamp: December 17, 2016, 07:29:12 pm
content: Before getting overly excited about USB spectrum analyzers, remember that a full size spectrum analyzer is built as a 'system'. That is to say, it is a combination of RF, analogue and digital technology in a box that is tested for performance and EM radiation. Any serious internal spurii are searched to source and addressed. This can be simple RF screening tape, additional filter chokes or more sophisticated digital electronics taming techniques such as lowering clock speeds and rounding the corners off of the digital square wave signals to reduce harmonic content. Full RF enclosure (biscuit tin) techniques are also employed where appropriate. Modern PC's run at amazing bus speeds and messing with the quality of the digital data stream to lower harmonic content is not normally a concern for the manufacture.I have lost count of the number of times I have helped someone who is struggling with unexpected spurii whilst looking at the sensitive areas of an RF circuit with a spectrum analyzer or whilst listening to weird noises coming out of a receiver under test. I walk over to the adjacent PC, TV, SMPSU or even fluorescent light, and switch them off. Like magic, the unexpected signals all disappear. Basic stuff, yes, but all techs have to learn about such sometime and the first time can be perplexing for them to say the least !If anyone decides to carry out diagnostics on RF converters or receivers, they should think carefully about whether having a PC running nearby is really such a good idea. Before anyone shouts European EMC directives, I know, I know, but once you connect cables and other equipment to a PC you can get all manner of weird emissions. USB3 was infamous for its horrendous RFI production when a cable was connected to the port.USB based SA's do have their place, but, like all equipment, they have limitations, some serious when used in EMC work. Most can, however, be addressed by a knowledgeable tech when they are understood. Placing laptops and desktop PC's anywhere near a sensitive receiving system is asking for trouble.One of the worst RFI offenders I found in my radio kit was an AOR SDU5500 panoramic display adapter. The AR5000A receiver was picking up all manner of spurii from the SDU. The SDU5500 radiated from the LCD and its backlight inverter. It was impossible to use when the AR5000 was connected to any form of indoor antenna. AOR expected all users to use an antenna outside the house noise field so obviously did not address the RFI emissions from their SDU.Finally, it is a wise tech the who tests his spectrum analyzer for internal spurri PLUS any spurii that the input circuit presents to the DUT. It is not a great anlayzer that actually injects spurii or local oscillator/ 1st Mixer products into the device that is connected to its input. Yes, such crappy SA's do exist !Fraser

author: G0HZU
author_rank: Super Contributor
timestamp: December 17, 2016, 07:46:57 pm
content: Quote from: joeqsmith on December 17, 2016, 06:48:27 pmI have fond memories of using the HP8569 back in the 1980s in my youth but it was never a high performance analyserI'm not sure which old Tek analyser you have but I don't rate any spectrum analyser from Tektronix. I've used a few over the years and hated them all. Their RTSA products are quite good though.I guess it's unrealistic to compare the BB60C against the best of the 1980s analysers but you did link to the cheapo oscillator thread so I'll give an example where an old HP8566B can still shine today. The best of today's lab grade analysers will be much better but you can buy an HP8566B for about £1000 today if you are patient. I paid £1000 for this one over 5 years ago as an ex rental sell off.A while back I made a suite of crude/cheapo oscillators to test my HP8566B for phase noise here at home because I didn't have a low phase noise source up at many GHz here at home back then. So I designed some crude free running oscillators using a printed resonator on Rogers 4003C PCB material with a target phase noise of -120dBc/Hz at 100kHz offset as this is close to the phase noise of the HP8566B here. In the youtube video below you can see me test one of them for stability. This was a 4.4GHz oscillator and it only drifted a few kHz in the test.From memory the loaded Q was just over 20 and I designed it on an EM simulator (Sonnet EM) to make sure the loop response was correct for optimal phase noise. A very crude analysis using Leeson's equation predicted about -120dBc/Hz at 100kHz offset at 4.4GHz for this oscillator design. The (typical) phase noise of the old HP8566B isn't quite this good but it did at least allow me to measure the phase noise to within a few dB of this at 100kHz offset at 4.4GHz. The oscillator noise is slightly lower than the HP8566B here.On a decent E5052A SSA at work I think this little oscillator managed -119dBc/Hz at 100kHz offset.What can the BB60C manage here? I'm going to guess it will be in the ballpark of -95dBc/Hz at 100kHz offset at 4.4GHz. Maybe >20dB worse than this 35 year old HP8566? So it would be fairly useless here as a tool to evaluate this oscillator. I could list other stuff the BB60C will be poor at but I think it is really aimed at people who want that big real time bandwidth to capture/process modern wideband signals. The HP8566B obviously can't compete here. It really is a case of horses for courses

author: G0HZU
author_rank: Super Contributor
timestamp: December 17, 2016, 09:36:05 pm
content: I managed to find this old test oscillator and I just measured it again on the HP8566B and you can see below that the combined phase noise of the oscillator and the HP8566B is about -117dBc/Hz at 100kHz offset. I think I've probably messed with this oscillator a few times since I made that youtube video but the performance is about the same.The true PN of the HP8566B is probably close to -120dBc/Hz here which is a pretty good result for such an old analyser. My Advantest TR4172 analyser manages -128dBc/Hz phase noise at 100kHz offset at 1GHz but it only covers up to 1800MHz. But this is one area where the big old analysers perform well because of the YIG oscillator based LO system.

author: joeqsmith
author_rank: Super Contributor
timestamp: December 17, 2016, 09:42:08 pm
content: The Tektronix I have is a 496P. I offered it to a local radio club but there was little interest.Most of the oscillators I play with can be measured with a scope. This was video where I compared a 1GHz oscillator using an old Wavecrest, my old LeCroy and then post processing the data using Labview.https://youtu.be/Bg45FuoeHZk?t=754QuoteAs you suggest, at the price it allows a hobbyist like myself to have some fun. The data sheet for the BB60C shows -93dBc/Hz @ 1GHz. I have no way to evaluate it at the frequencies you are interested in. As you suggest, this is not going to be the tool of choice for looking at phase noise. I think the Siglent had a wider dynamic range and lower phase noise. I really don't know what they offer to the digital crowd.

author: G0HZU
author_rank: Super Contributor
timestamp: December 17, 2016, 10:45:23 pm
content: QuoteI'm sure you will agree that it could also be used to do some serious signal analysis and it also offers the ability to scan very rapidly. So I suspect that this product will have very wide appeal professionally too.I guess the point I'm trying to make is that a lot of the old mid range HP/Tek/Advantest/Anritsu analysers from yesteryear really are obsolete now and offer limited functionality to a modern user. The exception to this will possibly be for ham/CB radio servicing/checking and for old school RF design of fairly simple devices. There's so much choice out there today I can't see the appeal of them now and I don't understand why people pay big bucks for them. For casual use I would much rather have a Siglent analyser or the BB60C than a lot of the old mid range analysers. But for serious RF design I would still reach for a decent old school lab analyser for most classic measurements.The very best $$$ analysers from this era are still very desirable for RF design and offer remarkable value for money today. My HP8568B cost me £125 about 10 yrs ago, the TR4172 was just £400 prior to this. I bought a faulty TR4172 a couple of years ago for £250 and it was easy to repair at no cost. But these fabulous old analysers can't offer the wideband SDR tools/toys of the modern digital IF type analysers of today like your BB60C.

author: Bicurico
author_rank: Super Contributor
timestamp: December 17, 2016, 11:09:40 pm
content: "I can't see the appeal of them now and I don't understand why people pay big bucks for them."I tried to explain that in my post: the reason, amongst other reasons, is simply the appeal of owning a premium lab equipment which in its days would cost a fortune.Call me crazy, but for sure I am not the only one, who would love to own such a HP, Agilent or R&S premium spectrum analyser in working condition. It's a collectors item. Some like vintage cars, some like vintage lab equipment.To give another example of a field I am more comfortable in: TV field meters. There is a device called the Kathrein MSK33 (http://www.radiomuseum.org/r/kathrein_sat_tv_fm_messempfaenger_msk_33g_bn_208302.html), which was in it's days (1999) the premium TV field meter, covering TV, CATV and SAT bands with options ranging from MPEG2 decoder, DVB-T board or return path measurement. Those devices can still be bought at eBay and their prices, after more than 15 years(!) sometimes still exceed 500 Euro. If you are lucky and patient, you can get one for much less.Is it worth it? I am not sure. For 1000 Euro you can purchase a brand new Rover Instruments entry level field meter that does MPEG2/MPEG4, DVB-S/S2/C/T and all new measurements with realtime spectrum. Much better than the Kathrein MSK33, except in one thing: the Kathrein MSK33 has the best constellation diagram implementation I have seen so far.AND: The Kathrein MSK33 is like a brick, solid and robust. It works fine, does its job and can be fully remote controlled through RS232. It even offers some kind of terminal remote interface! This is a classic device, which was marketed as an OEM by no other than R&S! Now look at the attached picture! This is the SAME device, but with R&S logos printed on it. It did not sell, but it makes my point!ANYTHING from R&S is sold for an expensive price. It is rare, it is highly collectable and in this case, reason does not matter. Even old R&S catalogs are sold on eBay for ridiculous prices.Regards,Vitor

author: G0HZU
author_rank: Super Contributor
timestamp: December 17, 2016, 11:45:30 pm
content: QuoteI think we agree on the premium analysers having a special appeal. I have several of the very best analysers here that money could buy in the 1980s. Eg an HP8568B, HP8566B and a couple of TR4172 analysers from Advantest. I was lucky enough to be a daily user of the HP8568B and the TR4172 back from 1990 onwards in our design labs. I now own the very same analysers I was using back then.Although it isn't my first choice analyser today, I still get a tingle when I turn on the HP8568B because I can remember how special this analyser was back then. The company couldn't afford to buy it so it was donated to us on a project by the customer and was effectively paid for by the UK taxpayer. This analyser was held in very high regard by all the top engineers at the company so I felt very privileged to be allowed to use it for design work back then. A year or so later the customer donated the TR4172 to the company and this analyser was outrageously expensive and it could outperform the HP8568B in several key areas. To now have both of them here at home is very special.The analysers that I think have limited appeal are the ones in the performance classes way below the HP8568B. I'm referring to the HP8590/1/x range, anything from Tek and pretty much anything from Anritsu or Advantest (apart from the TR4172).

author: joeqsmith
author_rank: Super Contributor
timestamp: December 18, 2016, 03:35:33 am
content: Quote from: G0HZU on December 17, 2016, 10:45:23 pmActually, I think my 496 has better phase noise than the BB60C, that's not saying much!I was surprised the local club had no interest.http://www.ebay.com/itm/Tektronix-496-Spectrum-Analyzer-/271899015273?hash=item3f4e71b869:g:Hn0AAOSwpdpVefx1I think what the BB60C can do for the price is pretty good and with time I suspect their software will continue to improve.

author: mmagin
author_rank: Frequent Contributor
timestamp: December 18, 2016, 04:06:19 am
content: Maybe among sub-3GHz spectrum analyzers.I spent about $2k a year and a half ago on a used HP 8562A. It's certainly doesn't have amazing phase noise specs or minimum resolution bandwidth, but it does go to 22 GHz, and is generally a reliable piece of equipment. As far as I can tell, I'd be looking at $13k+ (MSRP anyway) on the new market to get something which can do that frequency range with decent specifications.

author: Electro Fan
author_rank: Super Contributor
timestamp: December 18, 2016, 06:10:46 am
content: Quote from: Dan Moos on December 14, 2016, 05:04:11 amThere are a lot (almost all of the) users here with more experience, knowledge, and insight than me on EE stuff in general and Spectrum Analyzers in particular, but here are a few thoughts.As background, a while back I found a bit of a deal on a HP8561E. At the time Rigol looked like a good alternative and now Siglent looks good too.My sense is that a significant tradeoff between a vintage HP and the much newer Rigol/Siglent models is bandwidth. If you don't need the bandwidth of the HP vintage units, I'd think seriously about going with a Rigol or Siglent. Secondarily, I think there is also an advantage (in addition to bandwidth) in favor of the vintage HP's with respect to some performance specs, but I doubt the performance difference will be noticeable for most applications. So, what I think drives the market price proximity is mostly banwidth, followed by some combination of performance and nostalgia. However, in the end (or as the first decision point) either you need a certain amount of bandwidth or you don't. If you can live with the bandwidth and price of the Rigols and Siglents you will get not only decent performance but many more features and much greater (modern software driven) functionality. You will also get a warranty. As for which will last longer, a vintage HP purchased in 2016 or a new Rigol or new Siglent purchased in 2016, I don't know. It might depend on how well the vintage HP was maintained and how lucky we are with any of the models: HP, Rigol, or Siglent.In my case, I don't use the SA a real lot and I don't do a lot of serious stuff with it, but when I need it or have an idea about something I'd like to checkout (usually wifi related or ham related), it is a very enjoyable tool to use.Net, net: unless you have a specific stringent performance specification requirement, start by determining your required bandwidth; if the Siglent or Rigol meet the bandwidth requirement and fit your budget, go with the new technology. If you need more bandwidth than you can afford with Siglent or Rigol and you can find a good vintage HP that gives you the needed bandwidth and fits your budget, go with the HP. Either way, a Spectrum Analyzer is a pretty cool piece of test equipment that can help you measure and learn.PS, in my case I was attracted by 6 GHz bandwidth, pretty low noise specs, and very narrow RBW (1 Hz), plus some nostalgia and general confidence in HP. FWIW, after experiencing the fairly long sweep times that come with very narrow RBW and the additional but only modestly practical information derived from very narrow RBW, I probably put too much emphasis on the RBW. I don't think I will ever use 1 Hz RBW, and to be square most of the time I'm above 1 kHz and often much higher on the RBW. (But if I hadn't seen it for myself, I'd always be thinking "wow, I should have held out for 1 Hz RBW.") For anyone thinking about a SA, if you need narrow RBW and the sweep times are acceptable, go for it, but be careful about over paying for RBW you don't need. Bandwidth on the other hand, is a nice capability and I'm very happy that I held out for 6 GHz (still more bandwidth would have been nicer but for my purposes I don't know what I would have done with it). More FWIW, I get a much bigger kick out of looking at a 40 picosecond rise time on a Tektronix 7904 than I get out of looking at 1 Hz RBW on the HP8561E; go figure... YMMV

author: hendorog
author_rank: Super Contributor
timestamp: December 18, 2016, 06:41:50 am
content: Quote from: Electro Fan on December 18, 2016, 06:10:46 amConsider the Signalhound SA series along with Rigol and Siglent. You get more bang for your buck with SH, more flexibility, similar phase noise to Siglent (well ahead of the Rigol), portability and more RF bandwidth. Downsides are you need a PC, and the unorthodox LO.Consider the Signalhound BB60C and Tek RSA306 if you want big realtime bandwidth.

author: David Hess
author_rank: Super Contributor
timestamp: December 18, 2016, 06:42:28 am
content: Quote from: joeqsmith on December 14, 2016, 12:00:35 pm$400 for my 14 GHz digital sampling oscilloscope.

author: Electro Fan
author_rank: Super Contributor
timestamp: December 18, 2016, 06:54:17 am
content: Quote from: hendorog on December 18, 2016, 06:41:50 amhendorog, sorry I previously missed your comments (I scanned the thread too fast) when I made my post.To be clear and square, I have very little knowledge about Signalhound; I just used Rigol and Siglent as a couple ways to compare newer technology to vintage HP SA's. I have a hunch that folks like me who like nostalgic gear are probably into knobs and buttons on standalone gear, but I get the attraction of PC-based products and if they address the need for relatively higher bandwidth, it's good to have choices. So if Signalhound is better than a Rigol or Siglent for someone's needs, that's cool. We might be preaching to the same choir or a similar choir - I think bandwidth is a key decision-making criteria.PS, it might be a classic "pick 2 of the 3"; "you can have bandwidth, price, buttons - but only 2 of the 3"

author: hendorog
author_rank: Super Contributor
timestamp: December 18, 2016, 07:15:52 am
content: Quote from: Electro Fan on December 18, 2016, 06:54:17 amYep - it was just that you were talking new devices, price, and bandwidth. In that space SH just can't be left out as bandwidth at a low cost is one of their big advantages.

author: Fraser
author_rank: Super Contributor
timestamp: December 18, 2016, 01:47:02 pm
content: This has been an interesting thread.I was looking at micro metal lathes on eBay today and was surprised at how much people pay for very elderly Unimat lathes and even used more modern types. A modern SIEG C0 sells for around £300 delivered in the UK. People are paying more than that for a 1960's Unimat 1000 and a current auction has almost reached £300 on a very used modern SIEG C0.What has this to do with old SA prices ? Well sometimes the secondary market for equipment appears illogical. That is just life. If two or more people get into a bidding war over something they want, things can get silly.With respect to the lathes.... the venerable old Austrian made Unimat 1000 has a large following. Some are collectors, others had one, or wanted one when young. Each person has their reasons for buying stuff and a price that they are willing to pay. Some will pay way over the odds for what they desire.The question that really needs to be asked is why is it that anyone should be troubled by someone else overpaying on an old piece of equipment. It is their prerogative to do so is it not ? I personally look for bargains such as equipment poorly described, faulty or just too exotic to be recognised for its usefulness 😄 I am not rich enough to overpay on kit.A good question these days is how can a manufacturer make a half decent Spectrum analyser so cheaply. They have historically been a niche product that cost significant sums of money to manufacture. Modern electronics miniaturisation has enabled hobbyists to have access to acceptable performance within a reasonable budget. Be happy with that rather than wasting time wondering why other people still buy old SA's and pay, what seems to some, high prices. They have their reasons. Be happy for them getting the object of their desires 😄On a personal note, I own Advantest SA's. No HP kit in my lab and yet I am still very satisfied with what I can achieve with my SA's. You do not always need the best to get the job done. Way back when, people had to design and repair without access to an SA, they were just too exotic and expensive. These people got the job done by being top of the line techs who could innovate and make do with what they had available.Enjoy your life and worry not what others do with their money. It will do you no good. It is sick that people spend £10K on Christmas decorations for a posh London party...... but that is their life, not mine.Just my 2p worthFraser

author: tggzzz
author_rank: Super Contributor
timestamp: December 18, 2016, 03:16:19 pm
content: Quote from: Fraser on December 18, 2016, 01:47:02 pmVery true. That is the inspiration for the gliding aphorism in my .sig.

author: nctnico
author_rank: Super Contributor
timestamp: December 18, 2016, 03:23:12 pm
content: Quote from: Fraser on December 18, 2016, 01:47:02 pmAnd waste oodles of time in the process but that didn't matter because salaries where low. Also back then FCC/CE certification wasn't an issue like it is today. Nowadays you quickly need a spectrum analyser if you are serious about developing products which contain electronics.

author: G0HZU
author_rank: Super Contributor
timestamp: December 18, 2016, 04:03:35 pm
content: Quote from: tggzzz on December 18, 2016, 03:16:19 pmIn my case I absolutely did need the very best analysers available. My task back in the 1990s was to design the RF converter section of a suite of high performance receivers whose task it was to scan and digitise the RF spectrum from HF through several GHz and feed the output to a digital IF as it scanned. Back in those days the digital IF was a huge floorstanding rack system costing a lot of money. Today's equivalent digital IF DSP can be found in analysers like the Siglent at a tiny fraction of the cost, size and power.The HP8568B was sometimes used in place of the DSP system as an IF and it needed to maintain a very good dynamic range whilst displaying a span of several MHz with a fluid display rate. Back then the benchmark for a decent analyser was 80dB (IP3) SFDR with a 30kHz RBW (span of several MHz typically) and it needed to have very low phase noise as it was also a design tool for verifying the low noise synthesisers in the receiver. The 2HI performance had to be very good too. The HP8568B could just about match the 80dB requirement but the TR4172 was better by several dB and its 2HI performance was a class above the HP8568B here and its phase noise at 100kHz offset was much better than the 8568. The synthesisers I designed had to have ultra low spurious levels down to very low signal levels and the HP8568B and the TR4172 were just about good enough to do this work. To use a basic analyser and try and innovate around this wasn't a realistic option back then.The analysers we really wanted to use simply didn't exist in those days. We explored the limits of the HP8568B and eventually went over to the TR4172 for some of the design work. I think this particular TR4172 cost more than £60k when it was new in the mid/late 1980s but there were rumours that it cost even more because of the strong Yen back then. Luckily it was paid for with public money by the customer and you could have bought a very nice 4 bed house in the south east of the UK for that money back in those days

author: joeqsmith
author_rank: Super Contributor
timestamp: December 18, 2016, 06:13:10 pm
content: If measuring phase noise in the GHz range is your hobby, the old HPs may be a better buy. If you want to play with decoding your Extech wireless meter, I don't know what's on the new or used market that a hobbyist could afford. Of course the Extech meter is not a real good example, so here are QPSK and QAM16 signals at 5GHz.

author: joeqsmith
author_rank: Super Contributor
timestamp: December 18, 2016, 06:21:29 pm
content: The BB60C in swept, realtime and demodulation modes with a 5GHz QAM64 signal.

author: joeqsmith
author_rank: Super Contributor
timestamp: December 18, 2016, 07:00:33 pm
content: BB60C in swept mode with a 5.5GHz QAM256 signal. Well within the 27MHz bandwidth but Spike does not support demodulating it. National Instruments offers a communications toolkit for free. Maybe we can use this to decode the data......

author: G0HZU
author_rank: Super Contributor
timestamp: December 18, 2016, 07:22:22 pm
content: QuoteIf you want to hack or spoof your neighbour's wifi or play with GSM phones then you could buy something from Ettus Research insteadAFAIK their Rx+Tx SDRs cost less than the BB60C and you can do wideband Tx as well allowing all kinds of hacking and emulating.The Ettus box isn't a proper spectrum analyser as it is a direct conversion device, but it is far more interesting than the 'listen only' BB60C and some of their devices cover a very wide real time BW. There are lots of people providing FPGA data for these to emulate various modern digital systems. I'd much rather have the Ettus box compared to a BB60C.https://www.ettus.com/product/details/UN210-KITWe have loads of these at work as versatile playthings but no BB60C boxes

author: mmagin
author_rank: Frequent Contributor
timestamp: December 18, 2016, 08:04:40 pm
content: Quote from: Fraser on December 18, 2016, 01:47:02 pmI think the 3GHz or 7GHz analyzers benefit from a lot of well-traversed engineering territory and the availability of cheap parts suited to automated assembly. All of the mobile phone, wi-fi, etc products have driven the accessibility of products and techniques that put that stuff in the range of any manufacturer instead of a handful of industry-leading specialist manufacturers. 30 years ago that frequency range was pretty much only the domain of specialist designers of microwave equipment (telecom, military, space, test equipment).

author: joeqsmith
author_rank: Super Contributor
timestamp: December 18, 2016, 08:16:06 pm
content: I don't own a cell phone.

author: Fraser
author_rank: Super Contributor
timestamp: December 18, 2016, 09:04:09 pm
content: @mmagin,I agree. Direct to home satellite gave birth to the mass production of low noise 10 to 12GHz RF front end and down conversion technology at silly cheap prices. Having worked on SHF low noise block down converters over the years it has been interesting to see how the designs have developed and costs reduced, whilst still maintaining acceptable performance, and in the case of noise figures.... significant improvement. I am not suggesting that a typical SKY LNBD is lab grade though.... some are so crudely constructed that I am amazed that they actually work !5GHz used to be considered advanced RF technology, along with 10GHz. Now such frequencies are easily manufactured in bulk for pennies. Pretty amazing advances in technology and production processes. I was working with 40GHz and 75GHz equipment last year.... that is still less common and is expensive for 'building block' prototype modules. Try finding a reasonably priced SA that can cope with a 75GHz Local Oscillator 😆The way around having an inadequate bandwidth Spectrum analyzer, such as my Advantest 3GHz R3132 is not always to buy a very expensive higher bandwidth unit, but to use your RF Engineering knowledge. You buy a well specified down converter that contains an accurate PLL controlled Local Oscillator and comes with a calibration chart. Why buy a massively expensive Analyser when a block down converter for the frequency range of interest is cheaper ? I know it is not ideal but when working at 40GHz and above, you sometimes have to improvise in a carefully considered way to achieve the desired results. At least COTS >40GHz building blocks are now available at affordable prices.Fraser

author: G0HZU
author_rank: Super Contributor
timestamp: December 18, 2016, 09:22:04 pm
content: Quote from: joeqsmith on December 18, 2016, 08:16:06 pmThe point is that you can set it up to modulate or demodulate (emulate?) pretty much anything you like. Here's a video about setting up analogue FM demodulation. Maybe you don't listen to FM radio either and you just like decoding basic FSK from cheap chinese DMMs but this is a very versatile system. It supports GNU radio and there is a wealth of support out there.In the next video above have a look at 4:26 onwards to watch the Ettus box sniff through the 900MHz ISM band. Presumably there will be GNU radio apps readily available to listen/emulate/interact with a lot of the ISM stuff or you can decode stuff elsewhere.There's no way I'd spend $3k on a BB60C when I can get the Ettus box AND a decent old school HP spectrum analyser for the same money. At the minute I just use the HP8566B and the E4406A as the E4406A (with the Agilent 89600 SW) can do the FFT analysis and the data capture stuff I need to do but I keep meaning to buy my own Ettus box.

author: mmagin
author_rank: Frequent Contributor
timestamp: December 18, 2016, 09:57:48 pm
content: Quote from: Fraser on December 18, 2016, 09:04:09 pmI forgot about the direct broadcast satellite stuff.It's truly amazing how little there is in the modern LNBs. I pulled one of the 'universal' ones apart last year and it was like a single crystal, a single LO synthesizer + downconverter IC, 3 FETs for the frontend, and passives. The IC also managed the biasing of the FETs to select the horizontal or vertical antenna probe. All on a (presumably low-cost) microwave substrate and in a cast zinc enclosure which also forms the feedhorn.That application has the luxury of not having to be incredibly frequency stable, so I guess an ordinary crystal is good enough.

author: joeqsmith
author_rank: Super Contributor
timestamp: December 18, 2016, 10:09:50 pm
content: I watched a few videos about it. They were at NI Week 2016 and had a decent overview.Yea, it's pretty sad the best antique HPs can't decode some simple FSK from a cheap Chinese DMMs. I would think this would be a pretty basic thing to do. I don't think it would take much to connect a PC to my old Tektronix and decode it.

author: wkb
author_rank: Super Contributor
timestamp: December 18, 2016, 10:45:46 pm
content: Quote from: G0HZU on December 18, 2016, 04:03:35 pmSounds like a customer who in days gone by built Colossus

author: G0HZU
author_rank: Super Contributor
timestamp: December 18, 2016, 11:02:33 pm
content: QuoteIt isn't really designed for stuff like that but you can set it into a 'static' zero span mode and select 'linear' mode and there is a 21.4MHz IF output at the back. This can be fed to a limiter/quad demod in a remote box if you want to decode FM. It's years since anyone tried stuff like that at work but somewhere I have a 455kHz SA604 based limiter/demod box with a mixer at the front of it. The idea was that it could be used with various IF outputs from various analysers. Today, you could stick a modern DSO on the 21.4MHz IF output and capture/demodulate stuff and send it to a PC.Eg use the scope and the 89600 SW from Agilent to decode loads more stuff than FSK. Or maybe use a cheap SDR dongle on the IF output and run some freeware SDR SW on a PC with it. On the HP8566B this could presumably be done up to 22GHz.

author: joeqsmith
author_rank: Super Contributor
timestamp: December 18, 2016, 11:52:59 pm
content: Seems like as long as you had the IF and a way to record it you could be set. BB60C will stream the IQ directly and has a fair amount of support already built in for decoding. But as we saw, it could not decode the FSK. But at least no other hardware was needed to pull it off.Attached is the old 496 directly looking at the digital data. Zoom out I don't think you would have enough data to be able to decode the whole frame. So it would require something external as well.It would be simple enough to put something together without the SA to do it. The chipset they used is fairly common. Lots of eval boards for it already. For that matter, just use the radio that came with it. Not very useful but inexpensive. BB60C is a little more generic.

author: David Hess
author_rank: Super Contributor
timestamp: December 18, 2016, 11:57:07 pm
content: Quote from: mmagin on December 18, 2016, 08:04:40 pmI would have said Mini-Circuits (and maybe some others like Hittite?) made it possible. When did they start making their standardized parts, especially MMICs, available to anybody who could pay in small quantities?

author: G0HZU
author_rank: Super Contributor
timestamp: December 19, 2016, 12:33:08 am
content: Quote from: David Hess on December 18, 2016, 11:57:07 pmI can't comment on other peoples' experience but I regularly met the UK rep for Mini Circuits (JP N) in the early 1990s and there was no problem getting stuff in small qty. Their boast at the time was that you could have any component from their huge RF/IF Design catalogue inside a 3 week leadtime (USA to UK) even if it was not in stock anywhere. They would make it and deliver it inside 3wks. They also did custom versions of a lot of their parts even in those days. eg you could have a special (pregraded) mixer or amplifer to your own spec limits and it didn't cost much. They were one of the best suppliers around in this respect. Most stuff was available in a day or so if it was in the UK stock. They were great at providing samples and application info as well.Other sources for decent RF parts in those days included WJ and Avantek for exotic MMIC amplifiers, also Stanford Microwave for amps etc and PLL chips were generally Plessey or Motorola and often this required a design using external dual modulus prescaling. RF design was much harder back then because they were very few chipsets availableI also used to walk home 43 miles through the snow in my bare feet after each 72 hour shift.

author: G0HZU
author_rank: Super Contributor
timestamp: December 19, 2016, 12:59:21 am
content: QuoteThere are hidden tricks the HP8566/8 can do as it does have some basic DSP capability built in for post processing captured trace data. But I've never done anything useful with this feature. But I have played with it a few times. You don't need any additional hardware as the processor inside the analyser can be set to do it all for you. Each trace can be treated as a 1K record length and the analyser can do some basic DSP on this. eg it can produce and display a frequency spectrum from the trace data and this can be useful in zero span mode. I wonder if anyone ever (properly) used this feature in this old analyser?

author: R005T3r
author_rank: Frequent Contributor
timestamp: December 20, 2016, 06:00:44 pm
content: I hate to admit it, but at this point, why would you have to own a spectrum analyzer? I mean, you can use your oscilloscope as a "spectrum analyzer" for very basic stuff via the FFT command, to begin with, it will be slow, and you can't expect NASA resolution and whatever, but better than nothing.I mean, For 2000/4000 Euros you can get other instruments as well: why not a milliOhmmeter, why not an electronic load, or even better: an impeadence analyzer, an SMU... As now, I don't need a spectrum analyzer, and I'm fine with it since I won't use it, and If I had to I'd consider Siglent or an USB one.

author: joeqsmith
author_rank: Super Contributor
timestamp: December 20, 2016, 06:55:00 pm
content: You are right of course for those of us who play with electronics as a hobby. I certainly did not need all the cheap handheld meters I bought.

author: G0HZU
author_rank: Super Contributor
timestamp: December 20, 2016, 09:47:04 pm
content: QuoteI kind of agree and I'm surprised at just how many people on Eevblog seem to want a decent RF spectrum analyser. I need decent RF gear here to help me with research work and generally speaking, the better the analyser in terms of RF performance the easier it is to make reliable measurements with minimal uncertainty. Also, an 8 bit scope with FFT couldn't really do critical testing for linearity if you need to measure artefacts down to -70dBc or lower. There's other stuff the scope wont be able to do but I agree that most people probably don't need a decent spectrum analyser.I'm guessing that some people use them for casual EMC checking and maybe for looking at RF comms waveforms and some users will be radio hams.

author: SingedFingers
author_rank: Frequent Contributor
timestamp: December 21, 2016, 08:44:50 am
content: I'm going the awkward sod route and spending an old HP / new Rigol's worth of cash on building an inferior fully analogue tracking SA from scratch with sweep range of 100KHz-500MHz. That's an illogical dedication to a lost cause.I'm not sure if that's more or less healthy than spending a pile of cash on an old HP crate that is toast if anything breaks.

author: tggzzz
author_rank: Super Contributor
timestamp: December 21, 2016, 09:09:37 am
content: Quote from: SingedFingers on December 21, 2016, 08:44:50 amExcellentQuoteA little bit of what you fancy does you good. Have fun; that's what life's about.

author: SingedFingers
author_rank: Frequent Contributor
timestamp: December 21, 2016, 10:56:41 am
content: Wise words actually and motivating. Thank you

author: Fraser
author_rank: Super Contributor
timestamp: December 22, 2016, 07:15:00 pm
content: My experience of Advantest Spectrum Analysers has been very different. I had responsibility for over 50 Advantest SA's and the common faults were just age related after 20 years of service ! CRT would fail, PSU caps would fail and the odd 1st Mixer got fried. All, without exception, were repairable and I carried out some of the repairs myself. Unrepairable.... I think not, even for old models. If the BRL chaps thought that, they were not trying hard enoughAs for failing calibration.... nope never had issues with that side of things provided the PSU was running OK. I can quite believe that some models are better in this respect than others though. The R3132 has a Local Oscillator that does drift off frequency due to age. That is not difficult to fix an is understandable due to their age. It is just an adjustment and not a component replacement.Finally on the Advantest front. R&S became a partner with Advantest in Europe. I do not see R&S associating themselves with any company that does not produce high quality kit that they also stand by in case of failure.I can see from the post that BRL have a love of Agilent kit. I think many will agree that Agilent is the Gold Standard in test equipment. I do not disagree. Marconi in Chelmsford used HP test kit in the production of their test kit.....says it all reallyHaving used HP test kit, the only comments I would make are that it is often very large and heavy !...Well built ? absolutely, Custom parts used in the design ? Yes, Repairable ?..... only if the custom parts are still available. Great kit but you often need very deep pockets to purchase it new or used.Fraser

author: nctnico
author_rank: Super Contributor
timestamp: December 22, 2016, 07:36:58 pm
content: Quote from: Fraser on December 22, 2016, 07:15:00 pmI agree. I have owned a few Advantest SAs myself and so far none of them have been unrepairable. Then again I have succesfully repaired lots of stuff which others had given up on.

author: G0HZU
author_rank: Super Contributor
timestamp: December 22, 2016, 11:05:20 pm
content: QuoteMy experience of HP test kit is that the stuff designed and built in the 1960s and most of the 1970s was built to last. Then they started using lots of plastic and also cheaper switches, knobs and cases. Where I work the test gear gets moved around a lot from engineer to engineer and sees a LOT of use and not all users are sympathetic towards fragile user interfaces.Most of our HP kit from the 1980s just couldn't stand this intense use and most of the kit suffered from broken and missing buttons, knobs or worn out button membranes. Their scopes were the worst and also the portable HP8560 style analysers were very fragile. A lot of their older kit that used slider switches was notoriously unreliable. By contrast, we have quite a bit of Japanese test kit and this was designed to properly withstand heavy use and I don't think any of it ever suffered with broken buttons etc. HP/Agilent gear is very good technically but I don't think the build quality is that great any more.Assuming the Rigol and Siglent analysers don't have some kind of weakness in the PCB manuf/reflow process (leading to poor joints etc) then I would expect that the reliability will be pretty good compared to an old school HP analyser. Even if my HP8566B or my HP8568B was (somehow) 15 years younger I would still expect the Rigol and the Siglent analyser to be more reliable.I wouldn't swap my HP8566/8 for one of them but I would definitely allow the Siglent into my workroom and use it now and again. By contrast, there's no way I'd have/use an HP859x series analyser here or a Tek 496 or any of the test set analysers or the mid range HP/Anritsu/IFR/Advantest analysers from the 80s and 90s. Even if they were free. I'd rather have the empty space they aren't taking up in my house.

author: G0HZU
author_rank: Super Contributor
timestamp: December 22, 2016, 11:13:59 pm
content: As for my big old Advantest TR4172, I've been using this analyser for over 25 years and it is still working OK. I've had to do a few repairs on it but none involved any new parts apart from the backup battery (or BATTLY as Advantest call it on the PCB silk screen) and I had to swap the main OCXO across from another 4172 when mine aged too much.In terms of calibration we used to send it for a (£££) NAMAS calibration every year (same as UKAS calibration today) and it seemed to get through this OK.As for my HP8568B, that has been reliable too but this was partly due to it being treated like royalty at work and only a few people were allowed near it for many years. I have it here at home and it is still working OK but I did have to sort out the Z drive board for the CRT when the display went a bit fuzzy and dim. Didn't cost anything to repair. It was always calibrated and serviced at HP at great expense when it was in its most productive years at work. The HP8566B has needed several repairs over the years mainly poor connections and dried out/leaky caps and the same issues with the Z board and dim/fuzzy display.

author: G0HZU
author_rank: Super Contributor
timestamp: December 23, 2016, 01:07:55 am
content: QuoteI think that the build quality of my old Advantest is very rugged and impressive too.I don't have many shots of the insides but here is one that shows the main OXCO. It's the big box in the centre of the image with PIN CONNECTION written on it. You can look around this OCXO and see how solid this analyser is built. Advantest had a different approach to HP in that the favoured method was to use lots of high quality metal enclosures for the RF and IF sections and proper semi rigid cable was used everywhere. It meant the analyser was a fair bit bigger and heavier than the 8568B. HP used a motherboard and a series of screened slots for a lot of the IF stuff and cheaper flexible cables.See also the final amplifier module for the LO for the first mixer. This is arrowed in yellow below and is a huge high power amplifier. You can see how solid the build quality is for this amplifier. The first mixer in the 4172 runs with a +23dBm LO and contains 8 diodes ( compared to just two in the HP8568B).This was partly why we simply had to have the TR4172 back in those days. The mixer input IP3 and 2HI performance in the VHF region totally outclassed the HP8568B and we needed this performance for our design work. The build quality inside the TR4172 is very impressive although the construction methods are quite dated and inefficient as you can see by all the wasted space. I think the TR4172 was Takeda Riken's response to the fabulous HP8568 and I think they let their engineers off the leash to try and match the HP8568 in as many areas as possible. It managed it fairly well although I think most users will prefer the HP8568 as an all round package. The TR4172 has a few quirks and niggles and it doesn't feel as complete and polished as the HP8568. It is a big ugly thing as well although I do like using it

author: cncjerry
author_rank: Unknown
timestamp: December 24, 2016, 07:29:22 pm
content: I have to jump in hear as G0, Nct and one or two others have the same gear. I have an R3131A with TG that works perfectly, paid $750 for it two years ago. 9K to 3G or more. Only hang up is the RBW doesn't go that low.I just had to have an 8568B. Loved all the buttons, knobs and man, you can do some crazy things with it for surveillance using a little code. Stacked traces, etc. I then got a great deal on a matching 85685 preselector/preamp. That combination is lots of fun. I turns right on, I can get a measurement out in about 20 seconds, and I don't have to worry down to a .1DB. Read all the Rigol and Siglent threads about glitches, etc. That stuff would drive me crazy. Yes, this stack weighs in at 150lbs at least. I think the entire setup had a list price approaching 80k new.This summer I found a sat engineer selling an 8566B. I was the first of five that called him within a few hours of posting as he was asking $500. I worried all the way over there, waited in his driveway for 30 minutes. That one has near perfect cal constants but someone had been in it and didn't replace some of the metal covers. One I machined, the other I got from ebay. That analyzer is also near perfect.But if siglent or rigol made one with a TG that went from 9k to 3G for $1K I would probably snap it up since I travel a lot and would like to be able to shove it in my carry-on.

author: razberik
author_rank: Frequent Contributor
timestamp: December 26, 2016, 12:23:22 am
content: Quote from: G0HZU on December 23, 2016, 01:07:55 amPut them in here. Pleaseeee

author: PixieDust
author_rank: Frequent Contributor
timestamp: April 26, 2020, 11:13:31 am
content: Quote from: G0HZU on December 17, 2016, 12:50:27 amWhat's wrong with the HP859X range?

author: jjoonathan
author_rank: Frequent Contributor
timestamp: April 26, 2020, 04:33:36 pm
content: They're not elite enough for G0HZU!8560s and 8590s are heavy, have a monochrome screen, and don't have USB. Compared to a rigol or siglent, those are negatives. 8560s earn back their value with features like 26.5GHz, external mixer support, true YIG preselection, IF out, and possibly spurious + phase noise performance though I haven't looked recently. 8590s miss many of those highlights and don't do nearly as good of a job earning back their value, yet they still sell at a premium.My guess: there's a sizable market, not large but large enough, of people who know that 8590s work (because of experience or old industry guidelines) but don't have the RF knowledge to evaluate the rigols and siglents and declare them fit for purpose. It sounds dumb, but I'm sympathetic. My first "spectrum analyzers" were a SDR and then a SignalHound SA44B, both of which were a gigantic kick in the balls because the communities and marketing material do a very poor job of advertising the considerable shortcomings of ZIF and SIS respectively. Like most things, these evaluations are trivial once you understand them but intimidating until you do.

author: tggzzz
author_rank: Super Contributor
timestamp: April 26, 2020, 05:25:43 pm
content: Quote from: jjoonathan on April 26, 2020, 04:33:36 pmAs with many things, you will pay for your experience in time and/or money. That implies it is sensible to have a quick and cheap experiment, to clarify your understanding and needs.Now, back to recapping my hp8562b. I may take some photos of its guts, which would help answer this thread's title.For example, I wonder how much the custom four segment fold out hinges (with a screened PCB on each segment) cost to design and make

author: PixieDust
author_rank: Frequent Contributor
timestamp: April 27, 2020, 05:20:40 am
content: Quote from: jjoonathan on April 26, 2020, 04:33:36 pmI'm not familiar with any of the options that were listed that these devices lack. I guess they are mostly necessary for RF work?

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: April 27, 2020, 06:38:11 am
content: Quote from: PixieDust on April 27, 2020, 05:20:40 amExternal mixer would be needed to do any measurements above the frequency of the front panel connector. You would connect the LO of the spectrum analyzer to the external mixer, and the IF of the external mixer back to the spectrum analyzer. Usually you would bypass the first mixer within the spectrum analyzer (as it is now replaced by the external mixer).IF out is something you might use for radio communications measurements. Say you want to characterize the performance of an IQ transmitter at 5 GHz. To do these measurements you often need a scope as you want time-domain information. But a scope that can directly receive a 5 GHz signal would be very expensive, so you can use your spectrum analyzer as a 'receiver', and have it just down-conver the signal to a much lower IF, which you then connect to the scope.