Oscilloscope for home duty

[Mark A. Gulbrandsen]

Do you know if replacement parts still available for the 24xx series of Tek scopes? I recalll reading somewhere about front end devices being unobtainable.

Sphere Electronics in Canada is one of the best sources for N.O.S. and quality used TEK parts of all types. Also try the TEK Group at YAhoo as there are a number of retired TEK field engineers there.

Mark

[rdf]

Hi Mark. A belated thank you for that info. It happens Sphere is just across the Straight from me. A couple Canadian E-bay dealers sell these units regularly, including some near-perfect looking calibrated models out of Ottawa. I may just roll the dice. Thx again.

[jackinnj]

Originally posted by rdf

Hi jackinnj. Do you know if replacement parts still available for the 24xx series of Tek scopes? I recalll reading somewhere about front end devices being unobtainable.

There are folks out there who will fix 2xxx series scopes -- the trick is to buy one which isn't broken in the first place. Look at the sellers feedback and see that they mostly deal in scopes -- not baseball cards or stamps.

I have a word of caution with respect to the 2215 scopes -- the CRT mesh in these is easily deformed (from banging around) and the only fix is a new CRT.

[gootee]

Originally posted by rdf
Hi Mark. A belated thank you for that info. It happens Sphere is just across the Straight from me. A couple Canadian E-bay dealers sell these units regularly, including some near-perfect looking calibrated models out of Ottawa. I may just roll the dice. Thx again.

Yes, a 2465 (or A or B) is probably the best portable analog oscillocope ever made.

And yes, you cannot get actual "new" replacement parts, directly from Tektronix, anymore, for (at least) the 2400-series' Tek-custom ICs, some of which were prone to early failure. [Tek sold basically their whole IC operation and basically all of their IC designs to <some well-known IC manufacturer> (was it Maxim, maybe?), who then promptly refused to make them anymore, at the low volumes Tek wanted, killing the 2400-series!]

BUT, ALL of the parts "are" still available, from much-cheaper-than-working-scopes "parts units", if you're lucky (i.e. IF the one you buy for parts didn't die of what you need from it), from places such as ebay.com, or, monthly from http://www.govliquidation.com (where they might even be working units, but still often much cheaper because operational status is typically unknown, which tends to lower the bid prices, unless you're bidding against someone who thinks it's just like ebay), and, for the individual ICs, from dealers such as Sphere (Walter Shawlee, who owns Sphere, is a VERY good guy, too. Recommended.).

And, IF I recall correctly, there was a thread on the TekScopes group, at http://www.yahoogroups.com, a year or two ago, maybe, in which someone in-the-know pointed out either WHICH serial-number ranges OR which chip versions were susceptible to the early-failure problem, and why. It would be in the message archive, there. Or it could be asked again, now, and might be quickly answered by the OP, who was a regular there, at that time at least.

At any rate, knowing enough about THAT situation, one might be able to have more confidence in, say, a used 2465/A/B that they were considering buying (assuming one could ascertain the needed information about the prospective scope's custom IC(s) version(s) etc).

That brings to mind one advantageous "secret" about govliquidation.com: You often can't trust the military's "condition code" that was put on a unit by the person or organization it was "released" by, for sale. But it turns out that SOMETIMES that can be hugely in YOUR favor! e.g. If you actually GO to the warehouse site, during the pre-auction inspection period, you MIGHT get lucky, like I did quite a few times, and find a YELLOW TAG affixed to a piece of equipment that says something like "Unit is perfect. No money for CAL."!!! Eventually, it dawned on me: Budgeting. i.e. If they had NO money in their budget line-item for calibration (which is REQUIRED to be done on a very strict time-schedule, for U.S. Military equipment), but DID have money in their "new equipment" budget line-item... YOU WIN!

And, FWIW, I bought and resold "quite a few" Tektronix 2465, 2465A, and 2465B scopes, for several years, and only heard of one problem, with just a single one of them, which was a rectifier diode failure in the power supply that took only minutes to find and correct (once all of the upper board assemblies were removed, which can be "a bit of fun", the first time you try it [and beware of disconnecting the battery from the "NV"RAM...]).

And, FWIW, back when I was buying large lots of used or surplus scopes, the 2465 family was the ONLY type that never included ANY dead ones, and, in fact, presented no functional problems at all, when received in lots that could not be tested before bidding. Probably they were better-cared-for, by the original owners, than most other models, and they were more worth fixing. I don't know. I also didn't buy nearly as many of the 2465 family, overall. But every other older Tek model-series that I acquired as mil surplus in any significant quantities had DOA rates of about, oh, say, somewhere between 15% and 25%, maybe also depending on how diligent I was, and whether or not I personally inspected them, before bidding. (So, for personal use, probably one should try to buy two or three identical units at a time.) [I just thought of one other nice little secret about govliquidation.com: They usually have some wonderful, large, old power supplies that usually sell for almost nothing (although you might have to buy two or three pallets of them, at a time).]

Additionally, last I heard (a year or more ago), there were some guys on the TekScopes group who had some friends who were considering fabricating reverse-engineered replacements for some of the most-sought "unobtanium" Tek-custom ICs. But I haven't been following that group's message traffic, since then.

The 2465 family is getting relatively cheap, now, anyway, isn't it? I thought I saw 2465 scopes in the $300-$500 range, fairly often, a year or so ago, on ebay. A year or two before that they seemed to usually sell for more like $600+.

ONE more "FWIW": MY OWN Tektronix 2465 (one of my "main" scopes), purchased "used", has been running regularly for eight years or so, here, with no problems whatsoever. (HOW I love that scope! I just wish that I would have kept one of the 2465Bs, instead. Oh well...)

Oh wait! I actually have some stuff that I might be able to brag about, too: <brag> I ALSO LIKE my 500 MHz 7904A, a whole lot. And I like my 475(s), and the 2235M(s), and the 454 and 453, and the 7704, 7844, 7603(s), 7504, 422, 465, 465B, 2225, 2215A, 564, T912(s), and whatever else I still have here (except for the yucky 455(s))... even the old Heathkit IO-18 that I built when I was 12 years old (with its now-surprisingly-valuable Mullard "audio" tubes). Actually, I guess my "scope collection" is still rather large, albeit mostly just left over from my old "resale" inventory. I probably still have AT LEAST twenty or more scopes, (plus a Tek 575 Curve Tracer in perfect working condition), but sometimes almost can't remember which ones don't quite work properly, unless, of course, they're already partially disassembled. ;-) I also still have about a hundred 7000-series plug-ins (probably mostly just plain vertical amps and timebases; wish I'd kept a 7L5 and 7L12), and a few 5000-series mainframes and plugins, plus some TM500-series power supply mainframes and a few plug-ins for those (I like some of the TM500 stuff, a whole lot). I just realized, too, that I ALSO still have my set of TM500-based scope-CALIBRATION equipment, which came from a U.S. Navy Cal Lab (just barely out of their official calibration period, when I got them, which was very short on most cal-lab units). They have been repeatedly compared to many, many other instruments and have always seemed to still be "dead-on". I also have an original service manual for almost every model I own.</brag>

BTW, I'm not trying to sell anything, here. I work fifteen hours a day on "other stuff", now. And I usually don't have the time or much inclination to even check the stuff out, if someone does happen to want to buy it. And I'm probably way too conscientious about packing heavy-yet-fragile equipment so that it could survive a four-foot drop, which made that consume so much time and effort that I eventually developed a dislike of packing-and-shipping larger equipment, which made me tend to dislike even selling such equipment. (Ergo, here's some Free Advice for would-be equipment resellers: "Only buy and resell items that are very small and lightweight and that cost a whole lot.")

Sorry to have blathered-on for so long.

I would not hesitate to buy another 2465/A/B.

- Tom Gootee

http://www.fullnet.com/~tomg/index.html

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[Stefanoo]

Originally posted by gootee





You would probably usually want probes that have at least a slightly higher bandwidth than your scope has, so you're not seeing 6-dB-down when at f=BW (i.e. 3 dB down from scope BW plus 3 dB down from probe bandwidth). (So you might want to check whether or not a P6106 or P6106A would work with your scope.)

P610X probes, and Tek 400-series inputs, are typically spec'd for 500V peak. You'll usually use 10X probes, anyway. So 400v would look like 40v to your scope.

You can find more information about that by searching at http://groups.google.com (which now has the searchable archive of all text-only message-traffic from all Usenet newsgroups, from about 1981 to the present! It's a GOLDMINE!)


The official Tektronix website's now-somewhat-abbreviated list of matching probes for discontinued scopes is at:
http://www.tek.com/site/ps/0,,60-15264-INTRO_EN,00.html .



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Hello...

i have followed the various 3ds on oscilloscopes here on the forum and i finally came out with the desision of buying a Tektronix 467A, payed $200 on ebay which if i'm not wrong should be on the proper range of price.
i was undecided till the end IF a 465/B would have been the right choice or not.

This Tek 467A is not recalibrated unit but the picture were showing the scope at work propertly displaying a sine wave on the first channel and a square on the second one.


Unforutnatelly, the oscilloscope won't come with probes...and now i'm realizing how expencive they are ... augh!!!

I need your help on this subject guys.
On the link at the website that shows the probe's matching i have seen there are 2 choices: passive or active probes.

Accordingly on what i have read, active probes seem to be the best choice and they would give the better results.
Conversely are quite expencive and pointless having 2 channels if you don't have two probes ..and two probes...equal...a lot of money ...so...one is already too muccchhhh...

Other point found interesting...attenuation... 1X, 10X 100X... :

the 10X seems to be the most commen since it allows a medium width range signal analysis.

What would a reasonable price be for such a probe as the P6205 (10X active)?

I think this is the correct one for the mentioned oscilloscope, correct?
ehehe i wouldn't like to ened up spending a lot of money for a wrong probe that doesn't even fit on the scope inlet ...

I have found one of this a used one on ebay for $185:

- Is this the right price for such item or i can find one for a better deal?

- Is really true that a active probe is better than a passive one?

- How much would it be for a passive probe?


I'm sorry for all this questions, but i'm really not an expert and this is the reason of why...
Thanks in advance for the attention.


Best,
Stefano.

[AndrewT]

Hi,
a pair of universal 1X/10X probes are good for most work.
You could also buy a fixed 10x or 100x if you feel the need.
A box of various special tips for accessing small test points are very useful.
And be prepared to make up a special low inductance dual probe tip for special duty.

[resident]

wow! Nice and informative thread.
I'd like to buy an oscilloscope too. My current, Hitachi, has some problems at the one channel and one pot is broken.
I think I'll go for a 465A/B or 2465!
Right now I check some 465A/B on ebay and they go as low as $200-$300!

[Stefanoo]

if can find any...buy a 475A since it is suprerior scope.
I got mine for $200.
the 2400 serie is even better but more pricy.

[resident]

thanks Stefanoo!
You got it from eBay? $200 is a great price!
I'm a european too so if you know any great source please
inform me!

[Stefanoo]

thanks.

Just go through ebay and you'll find many good stuff.
Just a suggestion: first go aroud without having the intention to buy anything.
Once oyu got the idea onn the various sellers items and prices ...than you can try to negotiale a little bit the price with the seller on the item that you are better interested on!

anyways there are not other good 475A out...but you can find good 465 (the B version seems to be better)

If you are willing to spend $400 i found such a nice scopes around on ebay!!