Author Topic: Test Equipment Anonymous (TEA) group therapy thread (Read 18842106 times)

Cerebus · « **Reply #84025 on:** February 27, 2021, 05:38:37 pm »

Quote from: AVGresponding on February 27, 2021, 04:43:00 pm

~~British~~ Scottish engineering invented the modern world. Not with silly little 2.0 litre V10s though.

TFTFY. James Clark Maxwell, Alexander Graham Bell, Logie Baird, James Watt, the list goes on. I never cease to wonder at the way us Brits always say it's British if came from Scotland and is something to be proud of and it only becomes Scottish if it's dispreputable (Buckfast drinkers), yuckky (haggis*), or life threatening (Scottish Country Dancing).

*Personally I like haggis.

med6753 · « **Reply #84026 on:** February 27, 2021, 05:46:50 pm »

OK, Type 321A teardown.

7586 Nuvistor in vertical front end. Only tube (other than CRT) in scope. Later versions used an FET. I'd rather have the nuvistor. I have replacements and it is more resistant to overload. The probably difficult to source FET would pop if you looked at it sideways. And look at that crusty capacitor. That's just the tip of the iceberg.

More crusty capacitors.

Backside

Holy crusty capacitors Batman. No way is this scope gonna see power until all these are replaced. And since they are axial capacitors it's gonna cost...a lot.

Uh oh. Gorilla activity. That 2nd from the left diode has been replaced.

Battery compartment. Doesn't look like it has ever seen batteries. Nice and clean. There are all sorts of warnings and advisements concerning the use of heavy duty carbon-zinc and nicads and how to properly charge them. I have no intention of running this scope on batteries so I'm not installing any. I may in fact disable the charging circuit.

SilverSolder · « **Reply #84027 on:** February 27, 2021, 05:50:19 pm »

Quote from: Cerebus on February 27, 2021, 05:38:37 pm

[...]
*Personally I like haggis.

Me too, I was "converted" on a visit to Scotland 20 years ago!

bd139 · « **Reply #84028 on:** February 27, 2021, 05:51:19 pm »

Med: that’s in pretty good nick. The capacitors are to be expected but to not find any melted batteries in it is a win. Nice photos

med6753 · « **Reply #84029 on:** February 27, 2021, 05:52:24 pm »

Quote from: bd139 on February 27, 2021, 05:35:09 pm

Damn you hit the jackpot there. 422 is a really nice one too. Crack it open and take a look.

I'll teardown the Type 422 later. I don't want everyone to have pron overload.

bd139 · « **Reply #84030 on:** February 27, 2021, 05:53:18 pm »

Quote from: med6753 on February 27, 2021, 05:52:24 pm

Quote from: bd139 on February 27, 2021, 05:35:09 pm

Damn you hit the jackpot there. 422 is a really nice one too. Crack it open and take a look.

I'll teardown the Type 422 later. I don't want everyone to have pron overload.

Hey that’s what I’m here for

med6753 · « **Reply #84031 on:** February 27, 2021, 05:53:58 pm »

Quote from: bd139 on February 27, 2021, 05:51:19 pm

Med: that’s in pretty good nick. The capacitors are to be expected but to not find any melted batteries in it is a win. Nice photos

Yea, it does look to be in good shape other than the crusty caps. Mouser's gonna get a big order next week.

bd139 · « **Reply #84032 on:** February 27, 2021, 05:55:07 pm »

Quote from: med6753 on February 27, 2021, 05:53:58 pm

Quote from: bd139 on February 27, 2021, 05:51:19 pm
Med: that’s in pretty good nick. The capacitors are to be expected but to not find any melted batteries in it is a win. Nice photos

Yea, it does look to be in good shape other than the crusty caps. Mouser's gonna get a big order next week.

Yeah axials are annoyingly expensive. I notice in the vintage Tek museums page on the 321 they’ve replaced all the crusty bastards as well https://vintagetek.org/321-oscilloscope/

Specmaster · « **Reply #84033 on:** February 27, 2021, 05:59:01 pm »

@med, It looks like by just replacing those caps, it's going to fire straight up, it really is in good nick inside and the outside is not too shabby either, good snatch.

bd139 · « **Reply #84034 on:** February 27, 2021, 06:00:22 pm »

Don’t curse him. That thing is full of shonky germanium transistors

Saskia · « **Reply #84035 on:** February 27, 2021, 06:02:28 pm »

ok, my efforts at recycling.

Ho ho ho, I now have a machine ...

my somewhat Russian attempts re backplate show. But, it works, mate !

With 6 cores, 32 GB and a 2060 this thing is even usable.

Specmaster · « **Reply #84036 on:** February 27, 2021, 06:04:10 pm »

Quote from: bd139 on February 27, 2021, 05:55:07 pm

Quote from: med6753 on February 27, 2021, 05:53:58 pm
Quote from: bd139 on February 27, 2021, 05:51:19 pm
Med: that’s in pretty good nick. The capacitors are to be expected but to not find any melted batteries in it is a win. Nice photos

Yea, it does look to be in good shape other than the crusty caps. Mouser's gonna get a big order next week.

Yeah axials are annoyingly expensive. I notice in the vintage Tek museums page on the 321 they’ve replaced all the crusty bastards as well https://vintagetek.org/321-oscilloscope/

Thats where sleeving is your friend, extend the leads of normal caps and sleeve / heat shrink the leads, jobs done.

Cerebus · « **Reply #84037 on:** February 27, 2021, 06:04:55 pm »

There's something about a heatsink with a lonely TO-3 like that one that I find very appealing. I don't know if it's nostalgia for all the kit that looked that way in my youth, or whether it actually has sculptural or artistic merit, but I like it.

Cerebus · « **Reply #84038 on:** February 27, 2021, 06:06:14 pm »

Quote from: bd139 on February 27, 2021, 06:00:22 pm

Don’t curse him. That thing is full of shonky germanium transistors

Beat me to it. That's just what Med needs on a lonely weekend, someone to jinx his new toy.

med6753 · « **Reply #84039 on:** February 27, 2021, 06:07:41 pm »

Quote from: Saskia on February 27, 2021, 06:02:28 pm

ok, my efforts at recycling.

Ho ho ho, I now have a machine ...

my somewhat Russian attempts re backplate show. But, it works, mate !

With 6 cores, 32 GB and a 2060 this thing is even usable.

Specmaster · « **Reply #84040 on:** February 27, 2021, 06:17:00 pm »

That is one of my favourite tracks

tonyalbus · « **Reply #84041 on:** February 27, 2021, 06:18:47 pm »

Delta Elektronika Power Supply...from the '70 .. like new, i did have some help from there amazing Customer support, and its Dutch!

Zucca · « **Reply #84042 on:** February 27, 2021, 06:58:56 pm »

7,5 digit Keithely 2001 650€ German TEA Alert

med6753 · « **Reply #84043 on:** February 27, 2021, 07:05:20 pm »

OK, as requested. Type 422 pron. Please, no wanking.

The beat to crap covers and feet. Definitely gonna get paint.

Inside the front cover found a roll of silver solder.

The A/C supply pulls off the back. The Type 422 had a battery option that I guess would bolt on.

The inside is real clean. Has that distinctive old electronics smell.

And at first pass I see no evidence of any Gorilla activity. I was going to try to power it up but I think I'd best pull the A/C supply and check the capacitors first. But for now it's going back into the TEA closet.

Zucca · « **Reply #84044 on:** February 27, 2021, 07:11:39 pm »

Thanks med, best example what some pencils and skilled EE brains could produce back in those days.

tautech · « **Reply #84045 on:** February 27, 2021, 07:12:35 pm »

Quote from: bd139 on February 27, 2021, 06:00:22 pm

Don’t curse him. That thing is full of shonky germanium transistors

Those old HV ceramics might be toast too.

bd139 · « **Reply #84046 on:** February 27, 2021, 07:21:10 pm »

That 422 is a winner

PA0PBZ · « **Reply #84047 on:** February 27, 2021, 07:28:51 pm »

Quote from: tonyalbus on February 27, 2021, 06:18:47 pm

Delta Elektronika Power Supply...from the '70 .. like new, i did have some help from there amazing Customer support, and its Dutch!

Grats Tony for 1K subscribers!

nixiefreqq · « **Reply #84048 on:** February 27, 2021, 07:34:01 pm »

Quote from: med6753 on February 27, 2021, 05:46:50 pm

OK, Type 321A teardown.

7586 Nuvistor in vertical front end. Only tube (other than CRT) in scope. Later versions used an FET. I'd rather have the nuvistor. I have replacements and it is more resistant to overload. The probably difficult to source FET would pop if you looked at it sideways. And look at that crusty capacitor.

Holy crusty capacitors Batman. No way is this scope gonna see power until all these are replaced. And since they are axial capacitors it's gonna cost...a lot.

have seen that same type cap with crusty appearance on lots of HP gear and the caps always still tested good. (not that it matters to med the recap king).

does anyone know what causes the crusty-ness? it never appeared to be something coming out of the device, but more like just the surface deteriorating or maybe something actually growing on the outside?

anyone know for sure?

bd139 · « **Reply #84049 on:** February 27, 2021, 07:47:07 pm »

Think it’s polyurethane tubing and the problem is called blooming. Early PU wasn’t that stable. Capacitors might be fine even if they are pretty fugly. Worth testing some if you have an ESR meter.

That sprague black beauty to the right worries me more


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Author Topic: Test Equipment Anonymous (TEA) group therapy thread (Read 18842106 times)

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