Test Equipment Anonymous (TEA) group therapy thread

[BU508A]

bd139 is not the only one Ferengi in the bay. 

[bd139]

Well what do you know  , I have the £1 listing invitation for the next 4 days and the reason why I got and some of you didn't, I believe is because they have made the same offer to me many times lately and although have always accepted it, have failed miserably to list anything whereas you have managed it so it must be a profit related thingy.  You cost them loss of profits whereas if I sell something this time around, they make profit from me  Here I come.

Bingo so the answer is to take a few weeks off. I can manage that 

Edit: still no UPS delivery at 16:00. My TG320 is out for delivery and I really want it for the weekend 

[0culus]

Goodie box from Sphere came today...pics later. I got a really pristine Tek 191, the transistors I need to repair my second HP 3444A plugin, and the usual Sphere bag of extra goodies.

And here it is. The 191 works great. Recently calibrated, and looks exceptionally clean outside and in.

Here's my three. One of these days I suppose I'll spring for a Type 184. But after reading the frustrations You and Worsthorse had with the high frequency circuits I'm not sure I want that aggravation. 



Here's the difference between repaint (2 left) and original. Next to each other you can tell the difference. Apart you'd be hard pressed to know it's not original.

Nice! I'd say the type 184 isn't that bad as long as the example you find doesn't require extensive repairs. Mine boiled down to a bad Nuvistor and a bad socket on the the 500 MHz board. I robbed that board from worsthorse's parts unit he sent me and that solved that problem. I adjusted the crystal oven to 5 decimal places using my 53310A modulation domain analyzer (which is fed from the GPSDO). This provides far more than sufficient accuracy for an analog scope time base. The most fiddly part by far was getting the mutually coupled inductors on that board adjusted right. This requires much care and patience (and a fast oscilloscope...I used my 7104 for this). Your hand being present is enough to detune this circuit, so it becomes a matter of trying to find the adjustment that works better once you move your hand away!  And the big horse shoe shaped one has B+ on it so do not ground it with your hand!!!

[tggzzz]

Nice! I'd say the type 184 isn't that bad as long as the example you find doesn't require extensive repairs. Mine boiled down to a bad Nuvistor and a bad socket on the the 500 MHz board. I robbed that board from worsthorse's parts unit he sent me and that solved that problem. I adjusted the crystal oven to 5 decimal places using my 53310A modulation domain analyzer (which is fed from the GPSDO). This provides far more than sufficient accuracy for an analog scope time base. The most fiddly part by far was getting the mutually coupled inductors on that board adjusted right. This requires much care and patience (and a fast oscilloscope...I used my 7104 for this). Your hand being present is enough to detune this circuit, so it becomes a matter of trying to find the adjustment that works better once you move your hand away!  And the big horse shoe shaped one has B+ on it so do not ground it with your hand!!!

Remarkably, all I can say to that is "ditto on all counts".

[25 CPS]

As a heads up to any who may be interested, apparently someone on the bay of evil has stumbled onto a cache of those HP coffee mugs:


https://www.ebay.com/itm/114327183149?ul_noapp=true&shqty=2&isGTR=1#shId

There are allegedly more than ten available, and the price is not too insane compared to what I've seen them go for in the past.

Oh, my!

Nine gone, six left.  I wonder if she's surprised that they're selling so quickly?

Two left.

I just took a look and they're all sold out.  0 available / 15 sold according to the listing on eBay so now we know how many there were to start out with.

And I swear I'm going to get to the 3478A with the bad current fuse today plus a couple of other things.  Holy crow, life gets in the way sometimes.

[med6753]

Edit: still no UPS delivery at 16:00. My TG320 is out for delivery and I really want it for the weekend 

UPS is always consistent. Between 1100 hours and noon. You would think that USPS would be consistent since packages nearly always come with daily mail delivery. Not the case. Anytime between 1130 hours and 1400 hours.

FedEx is the loose cannon. You never know when they'll show up. I've had them deliver as late as 1830 hours.

[bd139]

UPS have turned up here at 9pm before. You just never know with them. Sometimes they don't even turn up 

[med6753]

Prepared a BOM for the PSU re-cap of the 5248L. Yes HP fan boys, I'm going to re-cap that beast. There's a lot of electrolytic cans to do but compared to the Type 535A I did earlier this year it's going to be a piece of cake. 

But I wasn't able to do this until I found a decent copy of the service manual. All the copies floating around on the net suck, big time. Including the copy on Aglient's website. Artek manuals had one, that you can read. It was $12.50 but worth it. 

[bd139]

I'd measure the cans myself (ESR and temperature) first. The big ass HP cans tend not to go bad even after 50 years or so. Save a small fortune

[mnementh]

Well what do you know  , I have the £1 listing invitation for the next 4 days and the reason why I got and some of you didn't, I believe is because they have made the same offer to me many times lately and although have always accepted it, have failed miserably to list anything whereas you have managed it so it must be a profit related thingy.  You cost them loss of profits whereas if I sell something this time around, they make profit from me  Here I come.

It's... Fuck eBay Friday. 

mnem

[mnementh]

Edit: still no UPS delivery at 16:00. My TG320 is out for delivery and I really want it for the weekend 

Careful what you wish for... 

mnem


Meanwhile, in some alternate universe...

[mnementh]

Goodie box from Sphere came today...pics later. I got a really pristine Tek 191, the transistors I need to repair my second HP 3444A plugin, and the usual Sphere bag of extra goodies.

And here it is. The 191 works great. Recently calibrated, and looks exceptionally clean outside and in.

Here's my three. One of these days I suppose I'll spring for a Type 184. But after reading the frustrations You and Worsthorse had with the high frequency circuits I'm not sure I want that aggravation... 

Nice! I'd say the type 184 isn't that bad as long as the example you find doesn't require extensive repairs. Mine boiled down to a bad Nuvistor and a bad socket on the the 500 MHz board. I robbed that board from worsthorse's parts unit he sent me and that solved that problem.

I adjusted the crystal oven to 5 decimal places using my 53310A modulation domain analyzer (which is fed from the GPSDO). This provides far more than sufficient accuracy for an analog scope time base. The most fiddly part by far was getting the mutually coupled inductors on that board adjusted right. This requires much care and patience (and a fast oscilloscope...I used my 7104 for this).

Your hand being present is enough to detune this circuit, so it becomes a matter of trying to find the adjustment that works better once you move your hand away!  And the big horse shoe shaped one has B+ on it so do not ground it with your hand!!!

   

I suspect that may be the exact use case for which Tek designed the big one in this set I got from Neomys Sapiens; it's 300mm long. 

mnem
I have 30cm and I know how to handle it. 

[bd139]

Fucking bastards 

Edit: ok so projects this weekend are limited to filing away the TME order and recapping the 8060a

[mnementh]

Sorry bd... I guess I jinxed ya.   

In OTHER pseud0-news...

https://newsthump.com/2020/07/31/oh-it-would-be-fckin-manchester-wouldnt-it-says-britain/

 

mnem
oy!

[bd139]

“The north”. Enough said. 

(Awaits flames)

[0culus]

Goodie box from Sphere came today...pics later. I got a really pristine Tek 191, the transistors I need to repair my second HP 3444A plugin, and the usual Sphere bag of extra goodies.

And here it is. The 191 works great. Recently calibrated, and looks exceptionally clean outside and in.

Here's my three. One of these days I suppose I'll spring for a Type 184. But after reading the frustrations You and Worsthorse had with the high frequency circuits I'm not sure I want that aggravation... 

Nice! I'd say the type 184 isn't that bad as long as the example you find doesn't require extensive repairs. Mine boiled down to a bad Nuvistor and a bad socket on the the 500 MHz board. I robbed that board from worsthorse's parts unit he sent me and that solved that problem.

I adjusted the crystal oven to 5 decimal places using my 53310A modulation domain analyzer (which is fed from the GPSDO). This provides far more than sufficient accuracy for an analog scope time base. The most fiddly part by far was getting the mutually coupled inductors on that board adjusted right. This requires much care and patience (and a fast oscilloscope...I used my 7104 for this).

Your hand being present is enough to detune this circuit, so it becomes a matter of trying to find the adjustment that works better once you move your hand away!  And the big horse shoe shaped one has B+ on it so do not ground it with your hand!!!

   

I suspect that may be the exact use case for which Tek designed the big one in this set I got from Neomys Sapiens; it's 300mm long. 

mnem
I have 30cm and I know how to handle it. 

Oh man. I wish I had that set. I used an insulated Wera screwdriver to help me manipulate it from a safe distance. If I had had a large noninductive tool it probably would have made the adjustments a lot easier to see too.

[med6753]

I'd measure the cans myself (ESR and temperature) first. The big ass HP cans tend not to go bad even after 50 years or so. Save a small fortune

HP uses the same cans as Tek (Sprague, CDE, or Mallory) and my attitude is the same. After 50+ years they gotta go. It really isn't all that expensive.

[mnementh]

At what point do we decide a cap is "old enough to retire"? I'd say if it's at the age where a man would be thinking about retirement, then a cap is also long-overdue. 

mnem
 

[mnementh]

   I suspect that may be the exact use case for which Tek designed the big one in this set I got from Neomys Sapiens; it's 300mm long. 

mnem
I have 30cm and I know how to handle it. 

Oh man. I wish I had that set. I used an insulated Wera screwdriver to help me manipulate it from a safe distance. If I had had a large noninductive tool it probably would have made the adjustments a lot easier to see too.

Ayup.

Next time let me know. I don't mind loaning by mail on these; at least in the Americas postage shouldn't be too painful.

Of course, this is also the type of tool that just screams "Print me!" 

mnem
 

[0culus]

I'd measure the cans myself (ESR and temperature) first. The big ass HP cans tend not to go bad even after 50 years or so. Save a small fortune

HP uses the same cans as Tek (Sprague, CDE, or Mallory) and my attitude is the same. After 50+ years they gotta go. It really isn't all that expensive.

I'm wondering if climate the instrument lived has something to do with how long these cans last. A lot of my stuff came from the desert, and I really only have a handful of things that have demonstrably bad caps and/or caps that I would condemn immediately (like paper caps or those "black beauty" type caps that audiophools love)

[med6753]

I'd measure the cans myself (ESR and temperature) first. The big ass HP cans tend not to go bad even after 50 years or so. Save a small fortune

HP uses the same cans as Tek (Sprague, CDE, or Mallory) and my attitude is the same. After 50+ years they gotta go. It really isn't all that expensive.

I'm wondering if climate the instrument lived has something to do with how long these cans last. A lot of my stuff came from the desert, and I really only have a handful of things that have demonstrably bad caps and/or caps that I would condemn immediately (like paper caps or those "black beauty" type caps that audiophools love)

Paper caps, wax caps, black beauties, etc regardless of climate WILL be leaky. The paper inside them degrades at a more or less fixed rate. Electrolytics are a crapshoot. Some could last a 100 years, some 5 years. My set point is once they qualify for an AARP card it's time to "retire" them. 

[factory]

I'd measure the cans myself (ESR and temperature) first. The big ass HP cans tend not to go bad even after 50 years or so. Save a small fortune

HP uses the same cans as Tek (Sprague, CDE, or Mallory) and my attitude is the same. After 50+ years they gotta go. It really isn't all that expensive.

Some of them do go open circuit, a couple of months ago I repaired a pair of HP 412A & 412AR meters, in both of them the low voltage can had failed open. In the case of the 412A cabinet model this one has the most inaccessible wiring.


Thankfully I have a box full of these RIFA caps, the 412A got re-stuffed in the original can & the 412AR got fitted underneath the chassis as there was lots of space (original disconnected).


BD139 may recognise one of these meters.



David

P.S. the picture fix (don't use the first) seems to be working well.

[bd139]

Nice. I’ve got my eye on the peak ESR meter to be honest. But I don’t need it because I built one which is good enough for the job.

I always test and only replace if there are signs of trouble.

[mnementh]

I'd measure the cans myself (ESR and temperature) first. The big ass HP cans tend not to go bad even after 50 years or so. Save a small fortune

HP uses the same cans as Tek (Sprague, CDE, or Mallory) and my attitude is the same. After 50+ years they gotta go. It really isn't all that expensive.

I'm wondering if climate the instrument lived has something to do with how long these cans last. A lot of my stuff came from the desert, and I really only have a handful of things that have demonstrably bad caps and/or caps that I would condemn immediately (like paper caps or those "black beauty" type caps that audiophools love)

Paper caps, wax caps, black beauties, etc regardless of climate WILL be leaky. The paper inside them degrades at a more or less fixed rate. Electrolytics are a crapshoot. Some could last a 100 years, some 5 years. My set point is once they qualify for an AARP card it's time to "retire" them.

So.... should we replace you with a newer production RIFA of similar value and voltage rating, or go sealed mylar instead...?

Agreed however... most non-ceramic capacitors, especially electrolytics, are livestock. They start dying of old age the minute they roll off the assembly line.

mnem
*definitely past my best by: date* 

[0culus]

I'd measure the cans myself (ESR and temperature) first. The big ass HP cans tend not to go bad even after 50 years or so. Save a small fortune

HP uses the same cans as Tek (Sprague, CDE, or Mallory) and my attitude is the same. After 50+ years they gotta go. It really isn't all that expensive.

I'm wondering if climate the instrument lived has something to do with how long these cans last. A lot of my stuff came from the desert, and I really only have a handful of things that have demonstrably bad caps and/or caps that I would condemn immediately (like paper caps or those "black beauty" type caps that audiophools love)

Paper caps, wax caps, black beauties, etc regardless of climate WILL be leaky. The paper inside them degrades at a more or less fixed rate. Electrolytics are a crapshoot. Some could last a 100 years, some 5 years. My set point is once they qualify for an AARP card it's time to "retire" them.

That's what I meant when I said "condemn immediately".