Test Equipment Anonymous (TEA) group therapy thread

[bitseeker]

This thread has become a veritable forum itself.

[xrunner]

This thread has become a veritable forum itself.

If it gets too big they might split us off from the Mothership. 

[mtdoc]

If it gets too big they might split us off from the Mothership. 

Nah, that ship is powered by GAS.

[neo]

I got my ID-22 and O-12 both recapped, the O-12 a while ago and the ID-22 today and i tested them together today. They work!

I now have a dual trace Heathkit 0-12 BUT it cuts into the bandwidth more than i thought. I figured it would only halve the bandwidth but now my top frequency, using the ID-22, is 2kHz whereas without it is 5 MHz.

I think it's the oscillator running slower than the sweep speed? That being the oscillator that switches channels.

[bitseeker]

Congrats on the successful recaps. That bandwidth drop does sound excessive, although I haven't used a setup like that before. I, too, would've expected to lose only half.

[Ero-Shan]

One might think that I might have enough toys to play with for the foreseeable future by now. This certainly is so, as I haven't even inventoried and checked all the gear that came rushing in. But I did make the mistake of looking at the bay the other day ... There was this counter that gave me a sudden urge, as it promised to strengthen my foothold in Nixieland. The seller accepted my offer, and so, about 1 year after my first universal counter (I always longed for counters - so many digits!) I can count to 5. (I ignore the ones in the MSO and DMMs).

The device was made by a german consumer electronics company, Nordmende, and counts up to 20 MHz. Of course it is not at eye level with test gear made by the usual suspects, it might have been an affordable device for radio/tv repair shops.

The housing is a bit sodden, and the handle is missing, but it works! Input was the 10 MHz ref from my PM6671:



Still fighting my guilty conscience!

[Cubdriver]

More nixies = good!  Congrats on your new acquisition!   

-Pat

[Cubdriver]

Oh, and if you gaze at the warmly glowing orange numerals for a bit, the guilt will fade away like it was never there.   

-Pat

[tggzzz]

SMDs are awesome for a lot of things in prototyping/one-offs... especially the smaller passives which lend themselves to being installed deadbug-style directly between pins of semis.

I had a Tek 485 with a faulty hybrid. Tacking an SMD resistor in the right place "repaired" it to the extent that its risetime was 1.25ns rather than 1ns. I pointed that out to the person that bought it; he was happy, so was I.

[beanflying]

I 'need' a Nixie testgear something but just what IDK 

 

[Cubdriver]

I 'need' a Nixie testgear something but just what IDK 

 

Counters


and digital meters


are always good options.  The nixie variety generally tend towards boat anchorishness, though, unless you go for smaller units like the Fluke 8100/8120/8200 for meters, and HP 5221/5321 or GenRad 1192 types for counters.  I'm sure there are other ones too, those are what I'm familiar with.

 

-Pat

[beanflying]

This one isn't far away but needs more Nixie Digits and Less $$ ones.

https://www.ebay.com.au/itm/Schlumberger-Solartron-A210-A-210-DIGITAL-VOLTMETER-TUBE-nixie-display-1975/122271040245?hash=item1c77ec02f5:g:mM0AAOSwo4pYUzjZ

[neo]

Congrats on the successful recaps. That bandwidth drop does sound excessive, although I haven't used a setup like that before. I, too, would've expected to lose only half.

I think what happens is that for the scope to see higher frequencies than 2k it has to run faster, then it runs so fast it see the switching rendering it useless. Maybe the switching is running slow?

[Ero-Shan]

  The nixie variety generally tend towards boat anchorishness, though, unless you go for smaller units like the Fluke 8100/8120/8200 for meters, and HP 5221/5321 or GenRad 1192 types for counters.  I'm sure there are other ones too, those are what I'm familiar with.

 

-Pat

That Nordmende counter is rather small and lightweight (maybe 1.5 kg). But half an hour ago I succumbed to another lure: a HP5325B "for parts, as no mains plug is available". 43 bucks with shipping, so even if it doesn't work and I can't fix it, I won't have to bite my own arse. Just to keep up the guilty feeling level. 

[Cubdriver]

  The nixie variety generally tend towards boat anchorishness, though, unless you go for smaller units like the Fluke 8100/8120/8200 for meters, and HP 5221/5321 or GenRad 1192 types for counters.  I'm sure there are other ones too, those are what I'm familiar with.

 

-Pat

That Nordmende counter is rather small and lightweight (maybe 1.5 kg). But half an hour ago I succumbed to another lure: a HP5325B "for parts, as no mains plug is available". 43 bucks with shipping, so even if it doesn't work and I can't fix it, I won't have to bite my own arse. Just to keep up the guilty feeling level. 

Excellent. The 5325B is a nice unit.  It's more than likely got the old PS-163 oval power connector.  It's got a switchable mains input, so it's happy on 120 or 230, and I'd be insurprised if it just works if you get power to it.

This is one I got a few years ago.  I haven't wrung it out yet, but it at least works partially based on what limited checking I've done so far:


More pics at
https://pmanning.smugmug.com/Electronics/HP-5325B-Universal-Counter

-Pat

[Ero-Shan]

Excellent. The 5325B is a nice unit.  It's more than likely got the old PS-163 oval power connector.  It's got a switchable mains input, so it's happy on 120 or 230, and I'd be unsurprised if it just works if you get power to it.

This is one I got a few years ago; I haven't yet fully wrung it out, but it seems to work at least partially based on some very limited testing.  The push button switch array mechanics may need some lubrication.


More pics at
https://pmanning.smugmug.com/Electronics/HP-5325B-Universal-Counter

-Pat

Thanks for the encouragement. IIRC, my HP 140A oscilloscope had the same power jack. First thing I did was to replace it with a IEC C14 standard connector, even it involved filing. The Nordmende counter came with a C10 jack, which I likewise exchanged with a C14 that fit quite well. And I still have quite a few of them. 

[Mr. Scram]

You can't win, can you? I had taken my oscilloscope apart to see what I could do about the somewhat noisy fan. I knew I lost one small nut, but couldn't find it anywhere. It must have fallen on the floor. To make sure it wasn't stuck somewhere in the device, I turned it both ways, knocked it, shook it and manipulated the power switch a couple of times. I had a box of the same sized nuts around, so replaced it upon reassembly. I fastened the inner shielding, turning the device on all side several times, fighting a few screws that wouldn't go back in and fastened the outer casing. Finally, after all was said and done, I put the oscilloscope back on the desk, turned it on and immediately heard a nice clink of the missing nut inside the inner shielding of the device.

Long story short, I took my oscilloscope apart twice today.

[bd139]

Every time you take something to bits you have to do it twice; it's the rules.

The other kind of TEA...

A few pages back I had a "fuck it" moment and decided to build a voltmeter because I missed my old HP 427A for poking around in RF circuits with an RF probe. Now I can't replicate that to any standard but I can get some of the way there.

Quick update ... enclosure sorted.

Gubbins:



Outside:



Todo: legend and divider (awaiting resistor delivery mid-next-week). Linearity is crazy good and it doesn't need zeroing regularly so slightly better than the average

[Specmaster]

Thank goodness you heard it fall, could have been really nasty had you not, and switched it on 

[Specmaster]

Every time you take something to bits you have to do it twice; it's the rules.

The other kind of TEA...

A few pages back I had a "fuck it" moment and decided to build a voltmeter because I missed my old HP 427A for poking around in RF circuits with an RF probe. Now I can't replicate that to any standard but I can get some of the way there.

Quick update ... enclosure sorted.

Gubbins:



Outside:



Todo: legend and divider (awaiting resistor delivery mid-next-week). Linearity is crazy good and it doesn't need zeroing regularly so slightly better than the average

Looking good, not so much bull shit but bloody smashing eh 

Whats the input impedance of this then?

[Mr. Scram]

Thank goodness you heard it fall, could have been really nasty had you not, and switched it on 

I heard it fall while I switched it on. 

But yeah, loose conductive bits inside your equipment typically are a bad thing. Considering the power supply is inside the inner shield, just plugging it in could have been bad. That one actually surprised me, but apparently it isn't too noisy as to ruin everything.

[bd139]

Whats the input impedance of this then?

10M. The divider, that doesn't exist yet, is responsible for setting the impedance between the terminals which is always less than the measurement amplifier. It's hacked up to measure direct without the divider at the moment so it's 10Tohm or the insulation resistance or leakage somewhere at the moment. If you put your hand near it, it pegs at the moment unless you stick a low impedance source on it.

Why 10M? Can use it with the RF probe I made for my VTVM then (if I chop the 1/4" jack off it):

[Mr. Scram]

Interesting. This oscilloscope has two AD9481 ADCs. Those do 250 MS/s each. I'm not sure how the total bandwidth ends up being 1 GS/s. I've heard of manufacturers interlocking hardware, but I can't imagine ending up with twice the samples each second.

I didn't check the bottom of the board. Maybe there are two more on there or something.

[Cerebus]

Interesting. This oscilloscope has two AD9481 ADCs. Those do 250 MS/s each. I'm not sure how the total bandwidth ends up being 1 GS/s. I've heard of manufacturers interlocking hardware, but I can't imagine ending up with twice the samples each second.

I didn't check the bottom of the board. Maybe there are two more on there or something.

Probably specsmanship, 1Gs/s with equivalent time sampling.

[Mr. Scram]

Probably specsmanship, 1Gs/s with equivalent time sampling.

I thought something similar, but the manual states 1 GS/s is the real-time sampling rate. Equivalent sampling is apparently equivalent to 25GS/s, or up to it.