It's a sad day here at BCS Technology Limited.

Our ancient Beckman dual-trace oscilloscope, state of the art in 1974, finally met its maker. This was not a case of cardiac arrest, just a "went to sleep and didn't wake up" event. Although this 'scope only had a 20 MHz bandwidth, it had served me well for all these years and still had the original CRT. It sufficed for testing and debugging my POC computer, although the 12.5 MHz Ø2 clock signal looked like a sine wave.

Anyhow, my biz partner and I did a little on-line shopping and a 200 MHz Tektronix unit will soon be taking up residence on the electronics bench. At least the POC's clock signal should look like a square wave, not something out of a flute.

As for the old Beckman, we're debating how to give it a proper sendoff. I'm in favor of dropping it off the top of the Willis Tower, my partner thinks we should put on the UP railroad track and wait for the next hotshot freight train. Trouble with either stunt is the Beckman was built as though it had to withstand a bomb blast. Were we to drop it from Willis Tower, it would probably cave in the sidewalk. Put it on the railroad track and it would most like cause a derailment. So I guess we'll just turn it over to the local electronics recycler. Sniff!

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

Sorry to hear the sad news about your old friend.

Is there any way it could be gotten into the hands of someone who could repair it and put it to use? The "didn't wake up in the morning" symptom suggests an easy fix. But who would the new owner be... A student? A ham? Scout group? High school? Hmmmmmmmmmmm!

BTW, congrats on your newly adopted Tek !

-- Jeff

Dunno that it's repairable. What failed was the CRT, which is no longer available. I knew the CRT would eventually fail and had searched a while back for a replacement. No such luck.

The electronics recycler in our area evaluates old gear and if they think it may be salvageable, will fix it up and donate it. If not, so be it.


We go lucky and found that unit just as the auction was ending. Activity had been minimal for some reason.

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

Whoops! OK, that's a pretty dire prognosis, then. Even if a brand new CRT were given to you, the labor to install & calibrate everything might be worth more than the value of the repaired unit. (Or more than you paid for the Tek.)

Going from 20 MHz bandwidth to 200 should make a nice change for you!

It's wonderful that you have such a service available. I salute their efforts. Sometimes on a small scale I try to play this role myself, but I've found it can be tough going.

-- Jeff

I could install a new CRT—if I could get one—and calibrate the unit. In a past life, I worked for a time at H-P's instrument repair depot near Chicago, so I have familiarity with the process. However, it would be like completely rebuilding a 1950 Buick. It would run like new again, but would still be 1950s technology.


I'm looking forward to it. In the last year of its life, the old Beckman's display was starting to get dim and blurry. Oh! Wait! That's my vision that's going dim and blurry.


When I replaced my old Zenith console TV I gave it to the recycler. They fixed it up and donated it to a homeless shelter.

It can be tough going because oftentimes the equipment either doesn't work at all or doesn't work right. With the huge variety of TVs, radios, etc., how is one to keep up with all of it?

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

Since I bought my new Rigol scope I am thinking about how to give away my old - even still at least qualitatively working - tektronix scope.

I asked around the university, even the local hacker space, but no one wanted it. Still have to get myself to put it on e-bay...

André

I would keep the case and board for parts. But, sorry for your loss. Sounds like you made off better though with the Tektronix! At least you got a model that's repairable...
BTW, you'll probably get some crappy probes like I did from another Ebay supplier when I bought my scope.

There are some "decent" I guess you can call them Japanese probes for 100Mhz floating around that are only about 30$, that is the type I use with my 10Mhz scope.

Dimitri

I've got good probes here, so it's not a problem.

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

Here's an update this topic.

I posted the above in May 2011. My former partner and I ended up returning the Tektronix unit due to a defective time base selector switch—in some positions the sweep would quit on occasion. We ended up getting a used H-P 1725A scope, which is a 275 MHz unit that H-P started producing c. 1978—the one we got was manufactured in 1982. Interesting feature: the 1725A has a linear power supply, complete with a large heat sink sticking out the back. That heat sink gets pretty warm after a period of usage.

Anyhow, fast-forward nine years and it appears the scope is dying of old age. Things are starting to not work and the two fastest sweep positions produce a messed-up display. It seems the high end bandwidth has deteriorated. Square waves aren't looking so square, and, no, it's not the probes—I am using high-end compensated probes.

Whatever the problem, I've done some checking around and getting this thing fixed will cost quite a bit money. Which brings the question of value into the picture. After all, the 1725A is 42 year old technology, and scope technology has greatly advanced since H-P first brought the unit to market. Just how much money should I be putting into test gear that is that old? Would my investment be better made in a new unit?

So, I've got a decision to make.

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

Well, I've also had old scopes that have deteriorated with time.... problem is, either finding a capable shop to repair it, or obtain the service manual and repair it yourself, which also assumes you have enough equipment to test and repair it, and of course to calibrate it.... more of a catch-22 scenario... which basically means you have enough functional test equipment already.

I really like the old HP and Tek gear... have a collection myself that I mainly use for analogue audio gear (vacuum tubes), so my Tek 2215a scopes are only 60 MHz and perfectly fine for my use. But back to the original question...

In my view, I would consider the main use of a new scope. If it's mainly for working on medium to high speed digital stuff, then one of the newer digital TFT scopes would likely be a better choice. Problem is, these can get pretty expensive and, like anything else that is MPU based, software updates and options are key and in some cases expensive. I would also ask (myself), if the existing scope was still fully functional, does it still meet current requirements for what you're doing at the shop? If yes, you can always shop around for another used one, but in reality it's just as old as what you have... albeit maybe not as many operating hours, but also unknown, so it might be a short term investment.

If I were going to buy a new scope today, I'd be looking at the new digital ones that can display typical measurements on screen, which simply makes it a quick and easy exercise to see what's going on. Software upgrades and available options would be of interest as well. Tek is nice... and also expensive. Rigol does get some nods on price/performance, but I haven't done any deep or recent research on them. Of course, your first decision is how much you're willing to spend on either a repair or a replacement.

I'm guessing my response may not be all that useful, but available funds will push you down a particular path.

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Regards, KM
https://github.com/floobydust

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http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

The switches on the 1725A are pretty accessible. I have tried cleaning them with contact cleaner but it hasn't helped. I suspect a number of things are going south in the thing and it's either fix it or replace it. I'm leaning toward replacing it.


That is one of the nice things about the 1725A: it's got those features. But I'm right back to the cost to fix it vs. the value. Almost all of my work involving a scope is digital these days, other than musical instrument amplifiers. If I'm going to invest in another scope it has to be one that will favor the type of work I do the most.


Exactly. I could probably fix the old beast if I could get parts, but it would mean having to have a second scope to look at signals, etc. I've checked around a bit in my area and haven't been able to find anyone qualified to repair test equipment. That is giving me a pretty hard push toward buying another scope.


Funny you should mention Rigol. A buddy of mine in Florida who does a lot of digital electronic stuff had bought a Rigol DS2202 scope last year when his old Tektronix unit he had had since 1984 coughed its cookies. He was quite impressed with it and especially liked the 8 inch display. I have looked at several brands and I happened to notice that some of the B-K scopes look suspiciously like the Rigol unit. They also have very similar specs, which makes me wonder if B-K's scopes are just Rigol units with a different name on the front panel.


Cost does get into the picture, but right now I'm more focused on features and reliability. That last item is what makes me hesitant to purchase a Rigol unit. While I haven't read anything to date that suggests it's not a good product, I am mindful of which country in which it is produced.

As for repairing the old one, unless I can find someone local that can do it, I will likely just scrap it and get a new one. Shipping a scope cross country to get it fixed has its own set of problems that come from rough handling by shippers. I want to avoid that.

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

I have a 1950's Heathkit vacuum tube-based oscilloscope that I restored (1 MHz bandwidth! 100 kHz sweep!), and a new Siglent SDS1204X-E (4 channel, 200 MHz). Love the Siglent.

I love the HeathKit too, but only use it for audio signals and when I need continuous X/Y inputs, as opposed to sampled.

That Siglent scope looks suspiciously similar to the Rigol scope I've been considering.

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x86?  We ain't got no x86.  We don't NEED no stinking x86!