Test Equipment Anonymous (TEA) group therapy thread

[Neomys Sapiens]

Since I promised it:


No salty beer anywhere. Eaten hot with a cup (or 2, or 3) of coffee. Mahlzeit! 

It looks strangely edible, while the combination with coffee seems to defer it's very nature and purpose. Generally, I can only advise anyone to be EXTREMELY WARY of german culinary customs north of the river Main!

[med6753]

Yep, big ass beast. And 21KV high voltage. 

[bd139]

Yep, big ass beast. And 21KV high voltage. 

[0culus]

Warning....picture heavy post.

7904 Porn. I opened it up today to brush out the dust. I still haven't tried to power it up and in fact I may not get to that until next week. Tomorrow I have to go to NYC and Friday take the lady copper on some doctor appointments. Back home Friday night since she has to work this weekend. On Sunday there is another hamfest. And today I just feel too lazy to do anything more than dust it out. 

The last calibration date I can find is 1980 on the plug-ins. I'd say it's a little overdue.  And speaking of the plug-ins.....I'll probably pre-test them in the 7603N to make sure they are OK.

*snip*

Ooooo, that's going to look amazing once cleaned up. Engineering porn at it's finest! That "particle accelerator" crt voltage is why it gets stupidly bright. I suppose the 7904 has a protection circuit that drops the brightness after 10 ms if you crank it up, like the 7904A? Really nice for super fast sweeps though. The only way to do better, I think, is the 7104 mcp.


I received the first of two P6106A probes NEW in the package I found for the 7A26 amplifier in my 7904A.

[worsthorse]

That's a mighty fine particle accelerator that one! 

The designers really wanted to discourage one from touching that CRT, eh? 

[mnementh]

...
The idea of a "forever" 2465B limited only by CRT hours and climate-controlled lifetime is intriguing; but as the DS1225AD has been successfully applied here as well now, I'm wondering if folks are just like "Okay... 60 years is long enough lifetime for ANY boat anchor, and the DS1225AD is the right family of parts for this application, so inherently safer" or if the fixed number of cycles lifetime I read about has some folks spooked about the real-world life expectancy of the FM16W08.
...

I would stick with the DS1225AD, but not for the reason of cycle life expectancy of the FM16W08.  Rather, the characteristics of the 2465B supporting circuitry is not suitable for the FM16W08 to guarantee safe power down.  It wasn't designed for that chip.  More detail here and in earlier posts in that thread:

  https://www.eevblog.com/forum/testgear/tektronix-2465b-oscilloscope-teardown/msg2012572/#msg2012572

My $0.02, since you asked.

Thanks Mark - that was exactly the sort of gotcha I feared might be in play here. 

Too much to hope for: Reasonable Cost/Readily Available/Permanent Replacement/100% For-Sure Compatible all in the same package. I did read on for few pages after the post I linked to, but this was considerably past that.

mnem
*back out into the suck*

[mnementh]

Yep, big ass beast. And 21KV high voltage. 

Looks like bd is making lunch again. 

mnem
*tzzzzt*

[Kosmic]

Looks like I should invest some time in this. Read the manuals. (Try to) calibrate it. Check the caps. Clean it up (the plastic case has a slightly rough surface; stickers do not really stick there - one more point on the plus side).

Make sure you spend some time adjusting the clock. The operation is briefly described in section 4.2.5 of the service manual. Had a good impact on the stability of my two 7061.

[Ero-Shan]

Since I promised it:     No salty beer anywhere. Eaten hot with a cup (or 2, or 3) of coffee. Mahlzeit! 

Looks like a yummy pizza pie!  What flavor are the ants sprinkled on top? Anise or dill?   

mnem
*agitating-ily*

Neither. Had to look up the english name (that'll stop most from regarding it as 'yummy'): kummel.

One of the simplest cakes to make.

[mnementh]

Looks like I should invest some time in this. Read the manuals. (Try to) calibrate it. Check the caps. Clean it up (the plastic case has a slightly rough surface; stickers do not really stick there - one more point on the plus side).

Make sure you spend some time adjusting the clock. The operation is briefly described in section 4.2.5 of the service manual. Had a good impact on the stability of my two 7061.

I know that process works wonders on my car radio; I get to work orders on time, my kids don't get mad because I left them in front of the school for 2 hours, I don't miss the Pharmacy while they're actually open and the hostility quotient from the vicinity of SWMBO is reduced by an order of magnitude. 

mnem
Why do I smell hot dogs cooking?

[Ero-Shan]

It looks strangely edible, while the combination with coffee seems to defer it's very nature and purpose. Generally, I can only advise anyone to be EXTREMELY WARY of german culinary customs north of the river Main!

Hey, I'm at a healthy distance to the south of the Main. But Swabian specialties are also not for everyone, including me.

[tggzzz]

I have a Solartron 7081. It s much better after I cooked for a couple of days, as per the  manual.

Basically, wrap it in a blanket, turn it on, and let internal temperature be say 40C?

I just finished making the dough for my 'salt cake' (Salzkuchen). Maybe I should put the 7061 in the oven with it. 
Several days of warm-up only to measure some voltages? That is no real use case. I have meters that don't drift noticeably after a few minutes of warm-up.
IIRC the maintenance manual requests 3 hours warm-up time. I'll let it run for some time and watch for the drift. .3 % would be really bad.

The voltage refs are crude by modern standards, so expect the 3hour warmup to continue.

The cooking is only beneficial if it has been in storage, and once off. RTFM

[tggzzz]

Looks like I should invest some time in this. Read the manuals. (Try to) calibrate it. Check the caps. Clean it up (the plastic case has a slightly rough surface; stickers do not really stick there - one more point on the plus side).

Make sure you spend some time adjusting the clock. The operation is briefly described in section 4.2.5 of the service manual. Had a good impact on the stability of my two 7061.

Good point; I found that necessary too

[tautech]

It appears tautech is aware of the mod, as he spoke with OP at the time. Tau, if you could share with us any knowledge you have, it would be awesome.

mnem
*tinker-putter-tinker*

You give my aging memory cells far too much credit. 
'Twas very interested at the time about most things 2465 and still am to some degree with thoughts of acquiring one of these classics but yeah......... nah I'll go with something more modern and capable.
Great to see MarkL chime in with 2c and keep ya'll on track. 

[0culus]

Had a chance to learn more about how to run this HP 1727A 'scope. Besides the variable persistence, I think the neatest feature of these crts is the low energy electron flood guns. They not only play a role in erasing the storage mesh, but you can also turn them on with the brightness knob and use it to increase contrast dramatically. For example, this allows you to see step response in situations where a "Regular" crt won't show it.

[Specmaster]

Tonight I actually read the SMM for the Solartron 7150 Plus meters and it seems I have been under the misapprehension that these beasts could be calibrated using the front panel controls, boy how wrong was I?

While it is perfectly possible self calibrate these meters if you have the right quality of reference signals, you have to use the GPIB interface, which I don't have so I'll have to live with the slight discrepancies between the readings and in any case they are certainly close enough for my requirements and while I like the allure of more digits on my meters, absolute accuracy is not paramount for me, 3 or 4 decimal places is plenty of resolution for my limited uses.

I have zero interest in falling into the black hole or rabbit hole thank you very much 

[Neomys Sapiens]

It looks strangely edible, while the combination with coffee seems to defer it's very nature and purpose. Generally, I can only advise anyone to be EXTREMELY WARY of german culinary customs north of the river Main!

Hey, I'm at a healthy distance to the south of the Main. But Swabian specialties are also not for everyone, including me.

In this case, I apologize. Most out of Swabia is fine with me. I had thought you were from NRW, and that area is not known to produce many things suitable for human consumption.

[Neomys Sapiens]

At least, some progress on the HP6825A (4Q-Power supply/Amplifier). It turned out to have been totally mis-jumpered at the rear terminal block now that I have the manual. Corrected after first making jumpers, because those from the current source are too flat to get over the ridges between the terminals.
Also, the resistors behind that brown spot seem ok. I got a reaction from the voltage control, but it is asymetric. -18..0..+24V. And the CC indicator is lit at all times. And the rotary switches feel totally kludgy. So there is some work left.

[mnementh]

(SNIP)
I have zero interest in falling into the black hole or rabbit hole thank you very much 

I think you spent too long staring over the edge; now the hole has an interest in YOU. 

mnem
"When you look into the abyss, it looks back into you. And it knows your name." ~mom

[Brumby]

(SNIP)
I have zero interest in falling into the black hole or rabbit hole thank you very much 

I think you spent too long staring over the edge; now the hole has an interest in YOU. 

mnem
"When you look into the abyss, it looks back into you. And it knows your name." ~mom

I was thinking along those very same lines.

However much someone declares their lack of interest in travelling a path, it is no guarantee that they will avoid doing so.

I'd keep a safety line attached at all times.  Not that it will prevent you from falling - or provide you with a means of escape.  No.  It is simply to inform .... when it's taught, you're down there!

[beanflying]

(SNIP)
I have zero interest in falling into the black hole or rabbit hole thank you very much 

I think you spent too long staring over the edge; now the hole has an interest in YOU. 

mnem
"When you look into the abyss, it looks back into you. And it knows your name." ~mom

I was thinking along those very same lines.

However much someone declares their lack of interest in travelling a path, it is no guarantee that they will avoid doing so.

I'd keep a safety line attached at all times.  Not that it will prevent you from falling - or provide you with a means of escape.  No.  It is simply to inform .... when it's taught, you're down there!

Beware of others sneaking up behind you and nudging you into that hole too @Brumby T- 4Hours 

[beanflying]

And in other non TEA the answer is just on $12 counted and seperated in 40 minutes. It seems I can make 460 more Bottle Openers without needing fresh stocks of Coinage 

[Kosmic]

The Heathkit Oscilloscope. It look worst then it is I think. The outside is really dirty. There is rust on the metal part around the screen. Med, if you want it, it's yours. Just cover shipping.

As I thought. Heathkit OL-1 3 inch scope. Thanks for taking the pictures. She's rough but she'll clean up. Obviously every one of those tubular caps will have to be replaced. That's a given. Probably many of the carbon comp resistors have drifted up too. Who ever wired it was kinda sloppy. There's only one thing that concerns me. That's not the original CRT. Original CRT was a 3GP1. That CRT is 3EP1 which I think is Russian. Please do me a favor. For some reason there's masking tape around the base of the CRT. Peel it back and there should be a silver "getter" like the tops of the tubes. Let me know if it's still silver. If it's grey or flaking off the CRT has air in it and no good.

If it's OK let me know how much to ship and I'll send you a postal money order. 

I don't see the typical "getter". Did my best to take some close up pics. Hope you can see something.

[Brumby]

Beware of others sneaking up behind you and nudging you into that hole too @Brumby T- 4Hours 

*@#$$#!!!*^%   

I missed it   

Been watching it for the last 5 days (including this morning) and remembered 8 minutes too late.    


.... breathe .... breathe ....

It had an opening bid which just sat there from early on.  A sniper came in at 4 seconds left, but didn't throw enough at it, so was unsuccessful.  While I would have sniped too, but at a higher amount, there is still the question of how much the opening bidder set as their max.

It is now time to be philosophical and allow myself to accept the possibility probability(?) that I would not have won the item, but merely have increased the amount the seller received.  <repeat until convinced>

[beanflying]

Live in hope the new owner will pop a hernia lifting it  Most likely a Dud and not worth fixing for the $20.52 AUD .......