Help me pick a spectrum analyzer... - Page 1
Forum section: electronics / testgear

author: Mr Simpleton
author_rank: Unknown
timestamp: August 29, 2013, 07:54:21 am
content: I'm looking to get a spectrum analyzer for my home lab, should do fine with <1.5GHz but higher frequency may come in handy later. As I have a long lasting love affair with the HP8568B which I use at day job, the only thing that holds me back is the size (and its age). So I turned to the 856X and 859X series. Looks like the 859X is not liked (I have never used one) and the 856X much preferred. Have spent some time with the 8563E (have one in the lab next door) but cannot say I'm overly impresesd by it's UI. Tried to use an Advantest U3641 and found it user unfriendly (beeing kind here). The R&S FSH3.... oh well that goes into the same class as U3641, not my cup of tea!Saw on fleabay that newer Agilent analyzers starting to show up at almost affordable prices ($4k), now that support is dropping. Question remains is how hard it will be to keep them running, finding spares etc.Parameters important to me are: low phase noise, RBW 10 Hz (<30Hz), logical UI, not to big/heavy.Has anyone made a fair comparason between old HP analyzer vs. new Rigol considering spending the same amount of money?

author: eman12
author_rank: Contributor
timestamp: August 29, 2013, 12:16:13 pm
content: Hi Mr Simpleton ,Sorry, I do not know if my response would be helpful or not, But I have got a 20MHz commercial USB scope card. It is connected to a PC/Notebook to work and hence is cheaper than the real ones's. It has got a spectrum analyzer as well, you can try google to find those kinds of scopes and see if it can help you or not,

author: Mr Simpleton
author_rank: Unknown
timestamp: August 29, 2013, 12:40:53 pm
content: Thanks... but these are not up to what I want it to perform... I currently have a Signal Hound analyzer covering up to 4.4GHz but I would really like to have a stand alone instrument with proven performance

author: Fsck
author_rank: Super Contributor
timestamp: August 29, 2013, 12:47:43 pm
content: Shahriar of The Signal Path tests a Rigol DSA1030A-TG3:I believe it fulfills your basic requirements. But, there's a whole 1.5 hours of video for you to form your own opinion of it.

author: olsenn
author_rank: Frequent Contributor
timestamp: August 29, 2013, 12:55:48 pm
content: Purchase a Rigol DSA815-TG for <$1500 and fully deck it out for free with the key-generator found here on the EEVblog forums. This will give you 1.5GHz and 10Hz RBW, plus all the measurement options, VSWR tools, EMI, etc. It has a MUCH faster sweep time than the SignalHound (albeit with a smaller operating bandwidth). Plus it's fully standalone.

author: G0HZU
author_rank: Super Contributor
timestamp: August 29, 2013, 05:01:56 pm
content: QuoteIt depends on what you class as low phase noise. For my use the Rigol phase noise is very poor. I'd imagine the front end linearity and input VSWR will be pretty ropey too. But it only costs £1000 and therefore is hard to criticise as an overall package in terms of value for money. In terms of VFM it is an excellent choiceRealistically, you only need low phase noise if you want to measure the phase noise on a VHF or UHF synthesiser or if you really do need to measure low level spurious signals that sit very close to the carrier. Not many people need to do this.I quite like the HP8560E although I prefer the older CRT versions of the HP8560E. The ones with the TFT display can be quite annoying to use as the graticule and trace tend to make it hard to make out data that sits close to the display graticule. The TFT display also looks VERY dated compared to the Rigol 815 display. Also, the HP8560,1,2,3 and HP859x series can suffer from dodgy membranes behind the front panel push buttons making some of the buttons get gradually deafer and deafer to button pressing. Usually it's the most commonly used buttons like the up or down buttons or the 1, 0 or decimal point buttons.So I can sympathise with your dilemma hereOne potential workaround on the phase noise is to buy the Rigol for general use but use some form of low noise downconverter to look at phase noise on a PC soundcard when you need to critically look at phase noise.However, it depends if you can live with the ropey input VSWR and poor linearity associated with the Rigol. For me these aspects of the performance would be showstoppers because of the extra measurement uncertainty they can introduce. Measurement uncertainty is a significant issue even with the big flagship analysers from HP/Agilent and it's only the more recent models like the PSA and PXA that have made decent advances in reducing measurement uncertainty. But these analysers are very expensive.But if you aren't going to be using it for semi serious design work or verification work then the Rigol is a tough act to beat in terms of VFM plus it is new and comes with a warranty.I would definitely run a mile from most of the HP859x models. They are effectively obsolete because they only offer a 70dB log range on the 80dB display, most have poor phase noise and the display is pretty woeful to look at. I class them as a technician's analyser and because the 856x range is available at similar money when buying used then it makes this analyser obsolete to those who know the performance difference between the models.

author: Mr Simpleton
author_rank: Unknown
timestamp: August 29, 2013, 07:10:13 pm
content: Great to get some sobering and sound advicesGuess it boils down to three possible items:1. Rigol DSA815, modern, easy to use, light weight2. HP8560E, semi-portable, high performance, somewhat high price, getting old.3. HP8568B, excellent UI, great performance, but big heavy and old. If I only had the space...I do have to muse over what I consider important and what I can live with out.Wish they had a 30 days trial on the Rigol...Dream on mate

author: orin
author_rank: Frequent Contributor
timestamp: August 30, 2013, 04:47:37 am
content: Quote from: Mr Simpleton on August 29, 2013, 07:10:13 pmPut something else on top of it... like a 5335A counter and perhaps a 3455A sandwitched between the RF and Display units. Oh yes, and a laptop on top of the stack to talk GPIB to it all.I went though this a few years back. No cheap Rigols then, just the SignalHound. Decided on a broken 8568B with the intent of fixing it, selling it and buying a SignalHound with the proceeds.I now have enough parts and spares to make an 8568A and an 8568B... (not to mention the test equipment it takes to get an 8568B in shape). I look at the marketing picture of the Rigol with the noise about half way up the display and wonder why I would want one if that's the best the marketing department come up with. Put the cal signal into the 8568A and the noise is in the bottom tenth of the display, not half way up. Yes, 8568A, I run the "A" RF unit as it seems to be quieter. I don't need the extra GPIB features or slight increase in responsiveness of the 8568B RF unit.FWIW, 8568A RF unit: $200, Display unit: $200, cables - RF: $110 from glkinst.com (I'm using one at the moment; it works fine; no difference to an HP cable that I've noticed and absolutely no point paying more on ebay for a questionable used cable and wonderfully fast service from glkinst.com when I ordered mine*), Bus: probably $100 on ebay. Just over $600 for everything (plus shipping of course, Ugh!).There are LCD screen upgrades available for $$$ and rumours of a new source for $$. I hope to upgrade my display unit to LCD some time soon for a few more decades of service.Orin.*I seem to recall I ordered mid-weekend and it shipped out Monday.

author: Mr Simpleton
author_rank: Unknown
timestamp: August 30, 2013, 07:49:58 am
content: I guess I'd better start cleaning up the mess in my shack then... a 8568 would be real sweet! I do have a minty 141T with-out the IF section but never got round to put it to work due to weight and size. Now the 8568 is a different kind of animalRepairing and calibrating one would be loads of fun and educational too during long winter nights. But where to find one locally? Shipping costs kills me...

author: nctnico
author_rank: Super Contributor
timestamp: August 30, 2013, 08:43:08 am
content: I'd take a look at an SA from Advantest (now part of R&S) as well. The 'newer' models are compact and relatively quiet.

author: MetraCollector
author_rank: Regular Contributor
timestamp: August 30, 2013, 09:10:52 am
content: Rigol is a toy with limited lifetime and it is useful for schools/universities, where is no matter of money lack.Go for HP instrument !

author: Mr Simpleton
author_rank: Unknown
timestamp: August 30, 2013, 09:37:48 am
content: As I initially said, I have a hard time likening the Advantest. Not sure why but it gives me the shivers, as do the FSH3 tooSo guess I'll look for a "cheap" but neat HP8568, 8560/1E...See a few clean ones on fleabay but ugh shipping is a killer, if they even ship outside of US

author: G0HZU
author_rank: Super Contributor
timestamp: August 30, 2013, 01:00:28 pm
content: If you do go for an HP8568B then I can give you some info about using one at home:The HP8568 is a really nice analyser but it is big, very heavy, consumes lots of power and makes lots of fan noise. None of this is a problem in a busy RF lab but get one home and put it in a smallish room (on a trolley?) and suddenly it takes centre stage and the fan noise can be very annoying. The other issue with the 8568 is the CRT is now beginning to become a weak point in terms of reliability. Many lose brightness or focus once the CRT gets tired.An awful lot of 8568s were bought for use in a rack for automated testing so they sit and run all day every day for many years and this takes its toll on the CRT. You can turn off the CRT in the menus for ATE use to preserve CRT life but I doubt many people cared enough to bother.However, it is by far the best bang for buck used analyser available if you can live with the issues above. I have one here and I also have the 22GHz HP8566B alongside it. The HP8568 is simply a fabulous piece of engineering and it oozes quality from the moment you switch it onNote: I'd be VERY wary of fitting an LCD replacement screen. I've seen the specs on one LCD screen that is marketed for the 8568B and it only offers 640 x 480 for the whole screen. This is not good.By comparison the display in the 8568B has 1000 x 1000 data points 'just' within the 10x10 graticule area. This is pretty awesome and should not be ruined by some shoddy LCD replacement. The LCD will have to do some unwanted and performance sapping scaling to make the 1000 x 1000 data block scale to the graticule area nested within the 'total' 640x480 available so there will be a notable loss in quality on 'moving' data. The CRT display draws the 1000 x 1000 datapoints using vectors and if you look closely at a healthy 8568B CRT then the display quality is wonderful. Sadly, many CRTs are tired and past their best.So I would advise looking for a HP8568B that has not been hammered in a rack mounted ATE environment. Check the CRT and check the front panel buttons all work (no dead or deaf buttons) and make sure there are no fault reports on the screen and make sure it can pass its automated self cal routine (takes a minute or so for the calibration program to self test and self calibrate and produce an onscreen report)Also, be prepared to buy a second one as a spares donor becaue it WILL fail at some point due to its age.Despite the HP8568B being such a fabulous analyser I do think that most casual/hobby users will be much better off with the little Rigol 815 because they won't need or appreciate the difference in RF performance. But they WILL like the small size, the portability, the modern colour display, the modern connectivity, the (useful but rather ropey) tracking generator and the fact that there is already a growing community of 815 users online to offer advice etc.

author: vk6zgo
author_rank: Super Contributor
timestamp: August 30, 2013, 01:33:11 pm
content: " I class them as a technician's analyser"?So the "lower orders" don't deserve a good Analyser?

author: G0HZU
author_rank: Super Contributor
timestamp: August 30, 2013, 02:17:05 pm
content: Quote from: vk6zgo on August 30, 2013, 01:33:11 pmI'm not sure if I've caused offence but what I mean is that the 859x analysers are better suited for casual field service use by a technician. They would also be useful for EMC work where the 70dB log range isn't such a limitation in performance.There's clearly a market for these analysers because HP sold loads of them. But I doubt many got used for serious synthesiser design work or for making production test measurements in a test department (by test engineers) where low measurement uncertainty is a 'key' requirement. Obviously, you 'can' use them for production testing but not with the same accuracy or versatility as the better HP modelsAt my place of work we only have one of them and it's in the customer support section. So it gets used for faultfinding. No way would we have one of these in our critical ATE racks in our test department or in any of the design labs where there are dozens and dozens of PSA or PXA or HP856x analysers in use.My main point on this forum about those HP859x analysers is that they are best avoided because a little patience can be rewarded by buying an HP856x model for little more money. Note that I'm giving that advice to hobby users because why have cotton when you can have silk for just a bit more money?

author: vk2hmc
author_rank: Contributor
timestamp: October 07, 2013, 10:04:25 pm
content: I have:8568B8566A3585A3582AThey are all HP and after using the excellent HP user interface, I find using other equipment can range be frustrating to annoting to use!With the HP SA's, everything I need to do is available quickly and easily from the front panel.I do a lot of repairs, calibration and precise measurements such as phase noise so I depend on my SA's to be accurate and available.Practically, the HP are heavy, large, noisy and probably consume a lot of juice even when in standby (mains is always connected to transformer and filter caps while plugged in) and generate substantial heat.So if you can't afford the space and the cooling then one of the ATTEN spec analyzers may fit your bill better.Also of note some of the Atten include built-in tracking generator.I would not expect to pay more than AUD1500 to door for an Atten.--marki