should I buy a tek 7104 scope? - Page 1
Forum section: electronics / testgear

author: linux-works
author_rank: Super Contributor
timestamp: February 21, 2014, 04:45:32 am
content: I was browsing my local tronics store and found a fairly clean 7104 scope with 4 plugins ready to go: 2 7a26 and 7b15 plus 7b10. cart and manual, too. (polaroid photo boxes as well, but really, who cares about those anymore?)they're asking something in the $500 range. I did a quick test of the unit and it does seem to work. controls are a little noisy but I plan to clean them all if/when I buy this.initially I was looking for a 2465A or B but this mainframe might be better off for me. I like the higher bandwidth (in theory, at least) and the fact that I can get plugins for it, or if my plugins turn bad, I can buy replacements (used, of course).anything I should check on this before buying it? is it reasonable to buy such an old unit these days? I do have space for it and I like the fact that, unlike the 2465 series, there are 2 timebases and each of the 4 inputs can be attenuated; whereas the 2465 only has 2 true attenuators and 2 'logic level' ones.I would lose the cursor feature if I don't get the 2465 style (are there cursor style plugins?). I have a digital scope (rigol) and that does an ok job for storage style tasks, but I really like being able to see the real waveform and 8bit vertical never really thrilled me, to be honest.talk me into this or out of it, pleaseI have about 2 days before the unit goes off-hold (I asked them to hold it for me while I think it over).lousy phone-cam pic of the scope:

author: Vgkid
author_rank: Super Contributor
timestamp: February 21, 2014, 05:03:56 am
content: That looks to be a good price,espicially with the cart/manuals. Is the price firm?http://m.ebay.com/itm/360848518916

author: linux-works
author_rank: Super Contributor
timestamp: February 21, 2014, 05:07:57 am
content: its not that one, and the price is quite a bit lower than that. no shipping needed as its my local store. I'll have to borrow a larger car or van to have it taken to my place, thoughI asked for a discount and the manager will be in tomorrow. I think they can give a bit of a discount. the buy-it price should be $500 or in that range.I'm thinking that for that price, no shipping and being able to try it first before buying blind, it seems like a good deal.then again, I'm not sure if I can get it calibrated or repaired, should I need that service later on. or, it could cost the value of the unit, itself, to have any work done on it. I may be able to do some work on it if it needs it, but I have so many projects going as it is, I'm hoping to be able to buy this and just USE IT, without any work other than some deoxit on the controls (if that's even a recommended thing).

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: February 21, 2014, 05:09:25 am
content: Hi,In the configuration you list the scope is limited to 200MHz by the 7A26 Vertical plugins. The 7B10 and 7B15 are the correct timebase plugins for this mainframe.The 7A26 gives you 1M Ohm inputs.To get the full 1GHz bandwidth of the mainframe you need two 7A29 vertical plugins. These are 50 Ohm input impedance.These scopes are little specialized. They have micro channel plate in the front of the CRT. This is a c=kind of image intensifier which makes it possible to see fast infrequent events. The scope has some protections to prevent the MCP from being burned.In my opinion they are not the best general purpose scope. You will probably be happier with a 2445 or 2465 type scope.Jay_Diddy_B

author: BravoV
author_rank: Super Contributor
timestamp: February 21, 2014, 05:14:31 am
content: ... or 2467 or B version, the fastest portable analog scope ever made on earth.

author: linux-works
author_rank: Super Contributor
timestamp: February 21, 2014, 05:18:05 am
content: thanks, jay.as I'm researching, I do see that these are not super fast plugins, but they do at least have 1meg input Z and don't have a limit of very low input voltage. the higher speed plugins seem to be 50ohms and also limited to 5v or something like that. may not be a limit for when I need really high speed work done and most of the time I think the 200mhz verticals are probably ok enough. right now I have the rigol 2ch 50mhz scope hacked to 100mhz and I also have the tek 2225 for low-noise work. the 2225 is a great little scope and I use it more often than my rigol.I'm assuming I can mix and match vertical plugins, so if I need high-z and can live with lower speed, I can use the existing modules and if I need to go faster, buy one of the 7a19 or 7a24 plugins.I see tons of 2465 style scopes all the time but I never see this one come up at local stores. maybe I never really paid attention to them until now, but if this is a good one, I don't want to let it get away

author: linux-works
author_rank: Super Contributor
timestamp: February 21, 2014, 05:20:35 am
content: Quote from: BravoV on February 21, 2014, 05:14:31 amyes, I would be open to the 2465 or 67. A or B model (not sure I want the base model; I've read that its not as well designed inside and the later models had some changes made for the better. something about the fan being special in the base model 2465, too; not sure what that's about).if I should walk away from the 7104 and go back to my old idea of the 24xx series, I can do that. I just need to see all sides of this decision. if the real cost of ownership of this old design is very high, that would be a deal breaker. the 24xx has some custom parts that are expensive to find and that makes me think twice about it.

author: linux-works
author_rank: Super Contributor
timestamp: February 21, 2014, 05:23:57 am
content: Quote from: Jay_Diddy_B on February 21, 2014, 05:09:25 amother than the crt burn-in risk (which there seems to be a timer to prevent that; you have to press the reset button to 'buy' more time) and the fact that the modules aren't as fast as the 2465b verticals, anything else that makes this NOT a great 'gen purpose scope' ?it takes regular probes, right? nothing special? no special ID contacts that I can see. as long as the probes are as fast as the vertical modules and the capacitance matches (or can be comp'd), then probes are a 'it should just work' thing on this model, right?

author: pomonabill221
author_rank: Frequent Contributor
timestamp: February 21, 2014, 05:29:56 am
content: I have a 7834 (400Mhz storage mainframe) with 7a26/7a13/7a18a/7b92a plugins and the service manual for all.I am asking 500 also.I even made a scope cart for it.It was calibrate and all switches cleaned as they were a bit noisy also.

author: BravoV
author_rank: Super Contributor
timestamp: February 21, 2014, 05:37:38 am
content: Quote from: linux-works on February 21, 2014, 05:20:35 amI own 2465B, the fan is just ordinary 12 volt fan that can be easily replaced, photo of the original fan from my 2465B. Made a tear down thread ->HERE.About 2467 or 2467B, these special made portable scopes use Micro Channel Plate aka "BrightEye" like 7104 does, really good on displaying a high speed signal. This thing beats 2465B out of the water.Just watch this video in this thread ->How much scope BW do you need ?made by our resident analog Tek scope guru, Alan (w2aew), he used 2467 in that video, and then read that thread throughly especially my question for him on displaying a really high speed signal, MCP crt equipped scope basically unbeatable.

author: linux-works
author_rank: Super Contributor
timestamp: February 21, 2014, 05:47:42 am
content: I saw a 2467 on the shelf at that same store. it looked like it was in not so great condition so I didn't really give it a 2nd thought. should I have?I'll be back there tomorrow so maybe I'll recheck it. I'm bringing some funct gens (they didn't seem to have anything good on their 'try it out' customer bench) and I'll see how well the scope displays things and if the trigger is stable. I know what to check for, generally, but not in this model's case. never really considered the mainframes but this one was just blocking my way when I was walking thru the store and I gave it a 2nd look, then a 3rd, then took it over to the try-it test bench and spent at least an hour fiddling with it.maybe even just for the novelty and learning experience. I just don't want to buy something and have it die very soon after and be very expensive to fix and calibrate again. this comes with no warranty. probably the testing I will do tomorrow is more than the store is doing, even with their 'green stickers' on the devices.

author: BravoV
author_rank: Super Contributor
timestamp: February 21, 2014, 05:58:15 am
content: Sometimes external appearance means nothing, its better you can power it on, see the diagnostic message and definitely a func gen side by side is the best to test this thing.Apart from the normal test, just make sure you're familiar with the delayed time base usage like shown in the Alan's video I mentioned, and test that too. Its definitely an eyes opener especially for spurious oscillation hunting.

author: linux-works
author_rank: Super Contributor
timestamp: February 21, 2014, 06:22:04 am
content: I just found this pdf online:http://www.vintagetek.org/wp-content/uploads/2011/10/7104-Springer-article-email-res.pdfit talks about the tech used in the 7104 series.in a way, it kind of scares me a little. is this going to be a high maintenance thing?let me use a car analogy (lol). I was once into BMW's and I had a 3-series and also a 5-series. I didn't have any 7's and asked about them, and the general concensus was that they are expensive to maintain and good for business short-term leases where you turn it over after a few years.I realize that this is way more than a 'few years' worth of use and that's commendable, but maybe this is toward the end of their useful life and things are going to start failing. that's what I don't know (about this semi-exotic sounding model). I don't want to buy something that is going to be more trouble than its worth.

author: linux-works
author_rank: Super Contributor
timestamp: February 21, 2014, 06:24:55 am
content: Quote from: pomonabill221 on February 21, 2014, 05:29:56 amI don't think there is a big market for the older/larger units. I know that I'd have trouble selling something this large to most current buyers.

author: BravoV
author_rank: Super Contributor
timestamp: February 21, 2014, 06:31:53 am
content: Regarding the concern on working life, its valid, but for digital counter part that has the same capabilities even "used", they're still in 4 digits range. Yes, its a gamble.Meanwhile, it will be interesting to watch this ebay item 321326055660 ended up, at least you will have a ball park number on market price when dealing with your local store. PS : This came with 400 Mhz probe, and it's accesories which sometimes they can be priced at between $100 and $200 range.Btw, talking bout high speed scope, remember, the probe is also very important, if you're still interested in analog Tek high speed scope, start looking or sniping for Tektronix P6139 or P6137, you will need that when it comes to probing 300 or 400 Mhz signal.

author: linux-works
author_rank: Super Contributor
timestamp: February 21, 2014, 06:47:36 am
content: last year I bought 2 NOS p6106 (250mhz) probes. that will at least be better than nothing, for now.I will keep an eye out for better probes, though.

author: BravoV
author_rank: Super Contributor
timestamp: February 21, 2014, 07:17:38 am
content: When it comes to high speed < 500Mhz passive probe, on this old Tek like 246X series scope, their input capacitance is 15pF, make sure the probe's compensation range that you're going to buy covers that, other wise it will not be optimal and not accurate.Good old Tek probes reference site ->http://www.barrytech.com/tektronix/probes/tekprobes.html

author: linux-works
author_rank: Super Contributor
timestamp: February 21, 2014, 07:27:12 am
content: I just checked the probe compat list and both types of my probes are listed as OK (p6063b is my other type, I have 2 of those). so, 200mhz and 250mhz are ok enough for me to start with, given I have them already and they are listed as within the cap range of the 7000 series.

author: linux-works
author_rank: Super Contributor
timestamp: February 21, 2014, 09:46:30 am
content: been reading the yahoo groups for tek.I think I finally see what this scope is about. you turn it on for short term captures then turn it off. the more you use the screen, the less life it has (seems quite drastic). there is a test that can be done to show how much of the screen has already been scorched or 'used up'.it sounds like its a bad long-term investment. the non-mcp versions of the scopes are much more tolerant to burn-in.I don't like to leave my scope on with the same signal there for extended periods of time, but the mcp seems to be a 'use, in itself, is destructive' design. fine for a business who can write-off a replacement when its time, but not so good for a regular guy who has limited funds. besides the fact that they stopped making this mcp decades ago.

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: February 21, 2014, 12:29:58 pm
content: Linux-works,Your comments about the 7104 being a special purpose scope are correct in my opinion. I haven't damaged the screen on mine. What I do find is that the screen saver blanks the screen when you are trying to make a measurement.I also have the 2467B with the MCP tube. It is has the same feature. That is why I prefer to use the 2445 or the 2465 family of scopes.Regards,Jay_Diddy_B

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: February 21, 2014, 07:36:47 pm
content: From my naive perspective I look at this unit as if it were a multi-engine plane. Each of those separate modules represents one more engine that might need fixing. This is just my gut reaction and not based on any expertise.

author: linux-works
author_rank: Super Contributor
timestamp: February 21, 2014, 07:58:15 pm
content: I've spent a good amount of time reading up on this scope and its display type. the fact that its a destructive screen by very use kind of deters me. it seems you are supposed to 'conserve' the screen and, ideally, only setup captures and trigger a photo-shot (polaroid, lol! oops, sorry..) and then turn the screen off.this is really not meant for daily use! the more I read, the more it seems to be a 'turn on and use only when really needed' kind of scope. a big luxury esp. given its huge size.I'm thinking more about the 2465 series again, I guess. you get some things and give some things up, but its what I was on the lookout for, anyway, when I stumbled upon the 7104 at the local store. just wanted to see if this was something I -had- to have or was just nice-to-have. seems much more of the 2nd type, to me, now

author: pomonabill221
author_rank: Frequent Contributor
timestamp: February 21, 2014, 08:01:41 pm
content: Quote from: linux-works on February 21, 2014, 06:24:55 amYes I know... but the 7104 is the same size as the 7834, and I just thought I would throw this out there...

author: w2aew
author_rank: Super Contributor
timestamp: February 21, 2014, 09:22:05 pm
content: Quote from: linux-works on February 21, 2014, 07:58:15 pmBack in the day, I used these 7104 and 2467 scopes (both have the MCP CRT) daily for well over a decade, where they never got shut off, and never had one of them have any problem with the CRT. I have a 2467 here that I use several times a week. If you leave the intensity at a decent viewable level (not excessive), the timer is either turned off, or set very long. It is intensity driven. Personally, I've never had this display shutdown timer ever cause me any frustration or problems during the scope's use.The 7104 is a very nice, flexible scope platform. Up to 1GHz BW with the right plug in. Multiple vert and horz plug-ins give you a lot of versatility with number of traces, delayed timebases, delayed triggering, etc. It's just a bit on the large side...

author: mazurov
author_rank: Frequent Contributor
timestamp: February 21, 2014, 10:00:05 pm
content: Before buying check the CRT - crank the brightness up until the whole screen illuminates and see if you have uneven spots anywhere on the screen. The spots themselves are not a big deal but they will help you negotiate the price. The top and bottom of the screen (where the numbers are) most likely will have burned-in numbers - use it to your advantage.The price is too high - over the years I bought 3 7104 mainframes never paying more than $100 shipped. The 7a26 are quite useful, anything faster (7a24 or 7a29(p)) are 50 Ohm and will require less convenient probes. The good price for any 7000-series plugin is $15 (except for samplers and spectrum analyzers which are difficult to get for less than a hundred bucks). You will likely need another timebase - the slowest sweep on 7b10 is 50ms/div. A 7104 on my desk has 7b87 in the right horizontal position (5sec/div - priceless :-)).In my opinion, a 7104 in a good working order makes much more sense than any other used analog scope. It used to be a $50K+ exotic instrument made for nuclear physicists; now it's just an amazing piece of old tech anyone can own. Easy to fix too and plugin selection makes it swiss army knife of scopes (just look at high-sensitivity diff. plugins and samplers).

author: JuiceKing
author_rank: Regular Contributor
timestamp: February 21, 2014, 10:50:56 pm
content: I bought a refurbished 2467 from workingman.mv on eBay and couldn't be more pleased. He routinely has very nice 2465s and 2467s for sale at reasonable prices. Another plus for these scopes is that probes are plentiful and not too expensive.

author: Rigby
author_rank: Super Contributor
timestamp: February 21, 2014, 11:03:27 pm
content: I have a 7633 and it is a great scope. I have a 7623, too, but it is not functioning.As a platform, for what it is worth, the 7000 series is an oldie but a goodie. they're huge, as you've seen, but I love working with mine.

author: G0HZU
author_rank: Super Contributor
timestamp: February 21, 2014, 11:04:33 pm
content: QuoteI hope no one is offended but here's my (contrasting) opinion. Obviously I don't expect many people to agree with my version of common sense but here goesIf that scope was left outside my house in the street I wouldn't be the one who would want to rescue it and keep it.Here's why...Do I really need a 1GHz analogue scope (no)Do I want a huge box like that using up valuable space when all it can do is display voltage vs time? (no) i.e. a far more sensible choice for me is the equally old Tek 465.Do I want to look at that user interface every time I want to make a basic measurement? (no)Do I want to listen to the noise it makes if I want a basic scope available (no)Do I want to have to move it around the bench or house? (no)I'm all for buying high end test gear but there's a reason there aren't 1GHz analogue scopes being marketed today. Supply and demand. If the electronics world in 2014 needed scopes like that then manufacturers would still make them.It's a wonderful piece of engineering from Tek but my advice to anyone is to only buy test gear you have a need for.To the OP: If you needed that scope then I would suggest you wouldn't be here asking for everyone's opinion.Also, on this forum you run the risk of someone like me telling you not to buy it

author: PaulAm
author_rank: Frequent Contributor
timestamp: February 21, 2014, 11:58:11 pm
content: I have 3 7000 series at the moment.Clearly they're not for everyone, but it's a nice scope and you can get plugins to turn it into anything from a spectrum analyzer to a curve tracer to a multi GHz sampling scope which makes up for the large footprint to an extent. It can also be used as a scopeDepends on what you plan to do with it, but it's still a useful piece of equipment.

author: G0HZU
author_rank: Super Contributor
timestamp: February 22, 2014, 12:33:58 am
content: You can certainly turn it into a toy spectrum analyserI still don't get the concept... A big heavy box that doesn't do anything relevant or well in 2014. By contrast there's plenty of older test gear from the 1960s that I think is still brilliant today. eg the HP431 and HP432 power meter with HP478A head. But the hideous spectrum analyser plug in for that scope is definitely for the diehard Tek collector rather than a serious userIf these scopes did anything uniquely relevant or useful in 2014 then the place I work at would have several of them or several modern equivalents and manufacturers would still make the modern equivalent.

author: mazurov
author_rank: Frequent Contributor
timestamp: February 22, 2014, 12:44:06 am
content: Quote from: G0HZU on February 22, 2014, 12:33:58 amDefine "relevant". And "well". Calibrating a counter to a GPSDO is quite relevant to me about once a year (haven't done it this year yet) and I can do it quite well with 7104.

author: G0HZU
author_rank: Super Contributor
timestamp: February 22, 2014, 01:48:35 am
content: Can I turn your question back on yourself and ask you the relevance of your example calibration?Why do you 'need' to calibrate a counter with a GPS standard and the scope? What is the ageing spec for the counter OCXO over 1 year? I'm asking these questions to see the relevance of the scope's performance to the stability of your counter over a year.

author: vk6zgo
author_rank: Super Contributor
timestamp: February 22, 2014, 02:36:16 am
content: I have a 7613,& yes,it is fairly large--about the size of a tower PC case!It was the best part of $100 less than a 465,& is more versatile.OK-it's not so easy to lug around,but I don't do much of that anymore.We used to drag these things around the State,along with HP180/81s with a SA plugin,(Nobody ever used the HP with a normal 'scope plugin),Tek 148 video Generator,VSB receiver,Gain & Delay Test Set,Diff Gain/phase Test set,AWA AF gen & N & D sets,Marconi Dev Meter(heavy-ish),HP410C with RF pickup,various test loads,etc,& the "piece de resistance"---A Rohde & Schwarz "Polyskop".The Polyskop was an RF sweeper/display unit which redefined the terms "huge & heavy"!Any 7000 series CRO pales into insignificance!!All the above said,the 7104 is getting a bit large for general use,as it is quite a bit wider than a normal 7000 series unit.If you really need the wide bandwidth,& can get the plugins cheap enough,it would be nice to have,but $500 is a bit much to pay,especially as I saw one a couple of years back for $150 at a mini-Hamfest!Oh,& about the "toy" Tektronix SA plugins---we had a couple which we never used in that job,but later,I worked for a TV Station which had a 7L12 at the Transmitter site.After a bit of playing around,"& holding your face just right"it was quite useable.In particular,I found that you could see fairly close to "Zero",so that I could use it to find a problem with aencoded stereo feed for an FM station.It also was useful for finding an interesting interference problem with the TV Station input video amplifiers.All the local FM Transmitters were 800kHz spaced,so there were "beat notes" spaced evenly at 800kHz intervals across the video bandwidth.A lab instrument?No,but not a "toy,either!

author: G0HZU
author_rank: Super Contributor
timestamp: February 22, 2014, 03:06:26 am
content: I remember using the old SWOB1 and SWOB2 Polyskops in the 1980s although they were ancient even in those days... and very heavy!I think it's good advice to only buy test gear that you have a serious use for. Maybe the OP needs the 1GHz analogue performance...I don't need a GPS reference here but if I had one I think I could measure it against another high spec reference using a two channel RF voltmeter I have here made by HP about 50 years ago that also measures phase. So this 1960s voltmeter technology would make the 1GHz Tek scope irrelevant (to me at least) in terms of calibrating a decent 10MHz reference against a GPS reference. I doubt it would be much better than the old voltmeter but then I don't know the specs of the scope.

author: Kilroy
author_rank: Regular Contributor
timestamp: February 22, 2014, 05:06:03 am
content: My advice...life's short, get the scope and have a blast.Who says it has to be a totally reasonable purchase, anyway? Heck, if I always used that as a basis for the way I spent my money I would have a bloody boring life. Electronics is supposed to be fun, and what could be more fun than owning a piece of cool history that, in the end, you can do something with and that looks way cooler sitting on your bench than the plastic play school boxes sold now. These old machines are beautifully executed works of engineering and if nothing else you can learn a lot by studying their circuits.$500 is too spendy though...use the fact that not many folks are going to have an interest in such a thing. Offer the guy $200 cash *if* everything checks out ok and it doesn't look like it was thrown out of a moving vehicle. Pull all the plugins and look them over. Take the cover off the mainframe and have a close look around. I like to see if anyone has been inside and replaced any components or messed with stuff...you can usually tell. You can get all kinds of plugins for these mainframes and you can get them cheap. Endless hours of harmless fun to piddle around with...and best of all, there's no intelligence insulting digital assery to contend with.Seriously though, seize the day. I wouldn't overthink things too much...unless, of course, you think your wife might shoot you in your sleep over it.

author: vk6zgo
author_rank: Super Contributor
timestamp: February 22, 2014, 08:20:17 am
content: Quote from: G0HZU on February 22, 2014, 03:06:26 amFunny thing,I saw a Polyskop at a Hamfest recently,& was sorely tempted to buy the old monster just for old time's sake.It still worked,but it was a 75 Ohm one,& the guy wanted extra for the 75/50 matching pads---not that it would matter much for Ham use!It was just too huge,though,& it was too far to the car park,so I went & had a cup of coffee & a beef roll,until the urge went away.The HP RF voltmeter sounds an interesting beast,though.If I found something like that,I might really be tempted!

author: linux-works
author_rank: Super Contributor
timestamp: February 22, 2014, 10:15:33 am
content: I gave it some more thought and decided this wasn't the scope for me, right now. I like the 7k mainframe idea but I might revisit it later.for now, I found a good deal on a 2465b and there happened to be an ebay coupon in my inbox for 10% which sweetened the deal.I may have to do some service on the 2465. might post some Q's here or on the yahoo forum if I run into issues.if anyone really wants that 7014, it will be 'freed up' at halted tomorrow, for those in the bay area who might want this.

author: G0HZU
author_rank: Super Contributor
timestamp: February 22, 2014, 03:17:18 pm
content: At the end of the day only you can decide if you need that scope or not...I have a typical sized main bench here and only a few items of test gear qualify to live on it full time (plus a few PSUs) The rest of the bench is kept clear and also the top shelf is kept clear. I can then customise the bench and shelf with the extra test items required for a specific task before putting them away afterwards. Nothing 'extra' goes on the bench unless it is needed and it has to justify its inclusion by providing the needed performance without taking up loads of bench space.So big items like a spectrum analyser get wheeled in on a trolley as required. No way would I have that big old Tek scope on a trolley because it doesn't bring anything new or relevant to the bench area. I don't need a 1GHz analogue scope and neither does the vast majority of the electronics industry.Someone will buy it. Either a collector or someone who wants it as a cool trophy to put on the bench. I'd rather have the free space to put something useful there when neededQuoteIt works up to 1GHz and HP claim it can be used to compare two reference standards to a few parts in 10^13 if you use the phase recorder output at the back. It can resolve down below 0.1degree so the idea is you plot the subtle phase drift over time on a plotter (or log it with a DMM) and then the frequency stability can be calculated from the phase drift over time. I believe that some of these meters are used for this purpose today in standards labs when checking the performance of various frequency references. It uses similar technology to sampling scopes to operate and this downconverts the signal to LF and effectively phase locks to one channel input using a PLL and lets you compare the other input with high precision for very subtle amounts of phase offset and drift.I can give a hastily worked example: I think that if it detects 0.5degree of phase drift in 10 seconds of plotter time then that equates to about 1.4E-11 error in frequency at 10MHz. = 0.00014Hz error at 10MHz.Hope I've done that OKI don't use it for this because I only have (and only need) OCXO references here for the stuff I do. I use it to measure complex impedance including negative impedances and also to look at phase shift in linear circuits using the Hi Z probes.

author: nctnico
author_rank: Super Contributor
timestamp: February 22, 2014, 03:36:00 pm
content: About comparing very small phase offsets: you can do the same with the X-Y mode of an oscilloscope (analog and DSO).

author: linux-works
author_rank: Super Contributor
timestamp: February 27, 2014, 06:08:33 am
content: just to complete this thread, my 'new' 2465b arrived today and its working, so I guess that will do me for my current scope needs. I called the store and told them to un-hold the 7104.here's my current collection:new guy is on the left/middle....now to re-cap him, re-fan him and re-dallas him

author: BravoV
author_rank: Super Contributor
timestamp: February 27, 2014, 06:27:53 am
content: Congratulation on the score, how much ?

author: linux-works
author_rank: Super Contributor
timestamp: February 27, 2014, 07:03:50 am
content: it was around $400, shipped, with tax included (calif to calif, so I had to pay tax.)somehow there was a 10% ebay coupon in my ebay inbox, so I used it for something goodI figure I might throw some money into a calibration, once I replace all the parts that I can. I've seen a guy on ebay who is in the sf bay area who does calibrations so I will contact him and see if I can make an appt to drive up there.the dallas nvram chip is going to give me a headache. I don't have an eeprom reader handy and don't want to spend $160 for one, either. I see the shop in greece (q-service?) sells already programmed dallas modules, but I'm not sure how fresh those are and I'd prefer to get a brand spanking new one, if I can.recapping should not be a problem for me, and I have a lead on the right fan for this scope (mouser carries it!) so once I get the soldering work done, I will want to have it cal'd and then I'm good for another 5-10 yrs.

author: BravoV
author_rank: Super Contributor
timestamp: February 27, 2014, 07:20:31 am
content: If you're going to re-cal, why you still need a programmer anyway ? The guy who do the cal should be able to do it for you I guess.Btw, the cheap < 50 bucks MiniPro TL866 as reviewed by Dave works fine with the Dallas BBSRAM in reading and writing, its officially supported.I got mine from Frankie (iloveelectronics)If you are going to replace that Dallas, buy from authorized distributor ONLY, since the DS1255AD (DS1225Y replacement) is electrically disconnected from the internal battery at the factory until the power applied for the 1st time. I bought mine from Digikey and just don't trust dodgy sellers like from ebay for this kind of stuff.Btw, don't forget to give that damn U800 chip a heatsink too.

author: ahnuts72
author_rank: Regular Contributor
timestamp: February 27, 2014, 07:22:38 am
content: https://www.eevblog.com/forum/index.php?topic=13509.0This will work for the Dallas chip.You beat me to it BravoVSent from my CM11 Nook HD+

author: casinada
author_rank: Frequent Contributor
timestamp: February 27, 2014, 07:30:16 am
content: Careful with the calibration, my nvram was dead and I reprogrammed a new one using the backed up data from the KO4BB site but some parameters were way off so I had to calibrate the best I could with the equipment I had. Mine is the BDM so I calibrated the DMM also the best I could but I didn't have a way to calibrate AC currents and AC voltages. Everything else works fine after recapping the power supplies and repairing the A5 board that had traces and components destroyed by the SMD caps. U600 was bad also but I bought one on Ebay but later I found out that it was for a 2445 and not for a 2465 (it will work but it doesn't have the full bandwidth). Be careful with seller 2465b from Ebay, make sure you ask all the appropriate questions. he is known for selling 2445 scopes modified to look like 2465 scopes. I bought the U600 from him. Enjoy the scope, it is a great instrument

author: linux-works
author_rank: Super Contributor
timestamp: February 27, 2014, 07:43:04 am
content: thanks, guys.the 2465b guy on ebay is who I was thinking about, for a calibration. I would not have any repair work done there (I hope to be able to do that part on my own) but I'm hoping he will be able to do the full cal. if anyone has experience with this tech, please PM me, as I'd like to make the best informed choice I can. I can drive to his location (not too far away) but if I'm better off mailing the scope to someone else, do PM me and let me know. I'd prefer to do this cal stuff once and be done with it.re: dallas; yes, if I get a full cal, backing up the chip is not important but I still want to be able to, myself. I'll look into that one linked a few posts above (thanks).I would only buy the dallas chip from digikey or mouser. I want the new one that 'starts' on first power-on, like you say.I did read something about using lower model boards and doing a 2465 upgrade. fortunately, I'm not in that boat nor am I buying a whole new scope. otoh, when I open THIS one up, who knows what I will find. I'll take pics when I get around to opening it.anyway, if anyone has hints on where to get a proper (and still cost effective) cal done, please do PM me.

author: linux-works
author_rank: Super Contributor
timestamp: February 27, 2014, 05:13:47 pm
content: Quote from: BravoV on February 27, 2014, 07:20:31 amI should try to contact him. I do like to give business to those on the forum. where is he located? I did see some ebay seller in washington (state) selling them and I prefer to avoid buying from china due to the long mailing wait.

author: Neganur
author_rank: Unknown
timestamp: February 27, 2014, 11:46:36 pm
content: Grats on the 2465bI had similar trouble deciding whether to go for the 7104 or a 246X.Got the 7104 in the end, shipped from New York all the way to Finland - and paid quite some tax on it too.I would agree that this isn't really a general purpose scope, but mine came with tons of plugins and I see no reason why I should not use it for 'regular' stuff.Somebody mentioned the spectrum analyzer plugins, I had one of them (7L12 - 1.8 GHz I think it was) and sold it again. While they're nice and work really well, I'd rather put that one in a different 7000-series frame than the 7104 and I couldn't be bothered with buying another frame. Also, the Rigol DSA815 is probably much more convenient.It really is quite bulky but you seem to have room for more than just one scope alreadyQuote from: linux-works on February 21, 2014, 09:46:30 amI wouldn't give too much on that (it's the same with SSD drives isn't it). While it is true that usage causes wear, I think most of the comments regarding the MCP are a bit paranoid (since there is no replacement etc).The instrument has likely seen more use than you will ever be able to add to it.Quote from: mazurov on February 21, 2014, 10:00:05 pmBe very careful with this. Don't just "crank it up". If I recall correctly, you need the beam off-screen (no beam without plugins btw) and preferably less-than-daylight lighting conditions.

author: linux-works
author_rank: Super Contributor
timestamp: February 28, 2014, 12:00:11 am
content: I think I'll try a 7000 series one of these days. later on, though; but I see the attraction of that system.I've started to see what work I have ahead of me on my recapping. I took these shots of the inside boards (have not taken anything apart yet other than the main skin). its a mixed thruhole and smd model (over 50k serial). it does not look bad to me, though. I don't see any leakage. does anyone see anything, here? I will replace the smd lytics anyway, but it does not look urgent.fullsize images:http://farm8.staticflickr.com/7356/12823675075_c65b39a9c2_o.jpghttp://farm3.staticflickr.com/2837/12824081684_520c4ddaa2_o.jpghttp://farm8.staticflickr.com/7453/12823742693_73d5c88873_o.jpg

author: linux-works
author_rank: Super Contributor
timestamp: February 28, 2014, 03:05:24 am
content: maybe I should start a new thread: repairing the 2465. at any rate, here's my first step: removing those nasty smd's.I used chip-quick, which was not the best thing for this job (nearly impossible to get it and the flux under the caps) but with enough waiting and patience, I could literally lift or push the caps away with my fingers. some more heating of pads, pushing the solder away with dry cotton swaps (q-tips) and that was that. no pad lifting whatsoever.btw, what is that 'tuning fork' looking set of traces that go under one of the smd's (to the right) ? guard traces or something else? I can possibly understand doing that under a chip core (if that was a ground plane) but this is something I've never seen before.

author: BravoV
author_rank: Super Contributor
timestamp: February 28, 2014, 05:14:16 am
content: Since you're going to recap, apart from the digital board capacitors, suggesting to read this ->Tektronix 2465B Oscilloscope Restoration Repair

author: linux-works
author_rank: Super Contributor
timestamp: February 28, 2014, 05:17:14 am
content: I missed the resistor part. I'll go back to that pdf again and see what I missed.is there enough info there to make an order from the mailorder places? do you happen to have the BOM you used (any vendor although I'm currently entering data in a mouser and also a digikey form)? I'm about to send it off, but if I can add those crucial resistors, I will. just want to get the mailorder sent out tonite or tomorrow so that it will get here mid next week.

author: BravoV
author_rank: Super Contributor
timestamp: February 28, 2014, 05:19:32 am
content: Attached the spreadsheet that I got while ago from the net, forgot where, its the list of parts replacement for the 2465A for low voltage part of the PSU though which is identical to 2465B.

author: BravoV
author_rank: Super Contributor
timestamp: February 28, 2014, 05:27:34 am
content: Quote from: linux-works on February 28, 2014, 03:05:24 amI think you should.

author: linux-works
author_rank: Super Contributor
timestamp: February 28, 2014, 05:56:01 am
content: ok, when the order arrives, I'll start a new thread, put the pics over there and it will all be under one place.I am not quite ready to tackle the a1 board. I want to see how things go one board at a time. I have a pretty full BOM so far (with some resistors from the condoraudio guy's pdf doc) and he mentioned some diodes too, so, what the heck. while I'm in there, I'll do as much as makes sense. I dont' want to open it again later unless I really have to.wow, $110 for mouser and $45 at digikey. I did double up on some items, but still, wow, that's a lot of money. at least I know I'm using first-class parts and perhaps some parts better than tek originally picked.

author: BravoV
author_rank: Super Contributor
timestamp: February 28, 2014, 05:59:10 am
content: Does the list include DIP socket for the Dallas ?

author: peter.mitchell
author_rank: Super Contributor
timestamp: February 28, 2014, 06:22:26 am
content: Quote from: linux-works on February 28, 2014, 03:05:24 am2x cheap soldering irons make quick work. then use a good iron for putting the new parts on.

author: linux-works
author_rank: Super Contributor
timestamp: February 28, 2014, 06:28:12 am
content: Quote from: BravoV on February 28, 2014, 05:59:10 amTHAT I think I have. or can get, locally, from a surplus store (nice little place called Halted in santa clara, ca).you trying to cost me more money at mouser? lol

author: linux-works
author_rank: Super Contributor
timestamp: February 28, 2014, 06:28:59 am
content: Quote from: peter.mitchell on February 28, 2014, 06:22:26 amwish I had hot tweezers. I would not try using 2 cheap irons as I'm too clumsy to handle that, well.

author: BravoV
author_rank: Super Contributor
timestamp: February 28, 2014, 08:00:45 am
content: Bryan, once you're going to backup the Dallas BBSRAM, will you do me a favor please ?What I need is the content of that socketed ROM chip that is labeled "160-5877-02" at your photo, really curious as mine is "160-5877-01" and it looks like we have a very similar board, though yours is newer. Fyi, pic of myA5 board.Well, just see it as a backup process for that ROM too.

author: linux-works
author_rank: Super Contributor
timestamp: February 28, 2014, 08:15:42 am
content: sure, if I do end up getting a chip programmer, I'll dump that one too if its supported.one thing I don't like about my firmware; when you press a button, the whole display panel blinks. I've heard that some do this and some do not. its very unrefined and I'm surprised tek left code in this state. does not serve any purpose other than to annoy the operator.maybe I'll want YOUR firmware, if yours doesn't blink

author: BravoV
author_rank: Super Contributor
timestamp: February 28, 2014, 08:24:13 am
content: Damn, same here, all panel's leds flicker when everytime a button is pushed.More details according other forum member here that has two 2465Bs, that one is not having this problem, read it ->HERE.

author: linux-works
author_rank: Super Contributor
timestamp: February 28, 2014, 08:39:19 am
content: aha, that's the thread I did read it in, in fact.its damned annoying!they punish the guys who bought later model smd scopes"yeah, we cost-reduced some of our boards, but we kind of messed up one of the shift registers. too late to fix it, 1000 units have already been built and shipped. maybe next model. meeting ajourned."lol