Test Equipment Anonymous (TEA) group therapy thread

[Zoli]

If anybody is interested in a HP rugged military scope:
https://vancouver.craigslist.org/bnc/ele/d/port-coquitlam-an-usm-338-hp-military/7850004960.html
And as usual, NAWTS.

[Shimonu]

Told my SO that I ordered a BM786. She laughed a bit as I've just gotten 2 bench multimeters, one of which is broken and she couldn't understand why I ordered another multimeter since I now have 2 bench multimeters but also 2 handheld.

Obviously it's because the BM786 is better than any of the handheld that I have. One of my handheld has fixed test leads so I can't plug other test leads in that one, but it auto ranges. My other handheld doesn't auto range and I noticed the bananaplugs don't have standard spacing so trying to put a BNC adapter didn't work at all. So I clearly need a third one that fixed all of this.

The working bench multimeter hasn't arrived yet and I'm working on fixing the one that has arrived but it got too frustrating with the handhelf that I have.

Today I got a supposedly defective current clamp, the seller didn't specify how it was broken though. I'm assuming it has to be the current clamp that doesn't work because I've tried everything else and there's nothing wrong with it.. 

[AVGresponding]

Told my SO that I ordered a BM786. She laughed a bit as I've just gotten 2 bench multimeters, one of which is broken and she couldn't understand why I ordered another multimeter since I now have 2 bench multimeters but also 2 handheld.

Obviously it's because the BM786 is better than any of the handheld that I have. One of my handheld has fixed test leads so I can't plug other test leads in that one, but it auto ranges. My other handheld doesn't auto range and I noticed the bananaplugs don't have standard spacing so trying to put a BNC adapter didn't work at all. So I clearly need a third one that fixed all of this.

The working bench multimeter hasn't arrived yet and I'm working on fixing the one that has arrived but it got too frustrating with the handhelf that I have.

Today I got a supposedly defective current clamp, the seller didn't specify how it was broken though. I'm assuming it has to be the current clamp that doesn't work because I've tried everything else and there's nothing wrong with it.. 

Laughing a bit is a lot better than shouting a bit!

[Cyclotron]

I have had the wants for a good example of a 3245A Universal Source.  That want landed me this very nicely kept unit this week.

[Addicted2AnalogTek]

Very nice 3245A! It looks very clean.  I see those 1991 date code Dallas NV SRAMS. Is it functional?

(edit add)  Also, whatever component that is next to U902 on B output board looks suspect, or maybe just dirty.

[Cyclotron]

Very nice 3245A! It looks very clean.  I see those 1991 date code Dallas NV SRAMS. Is it functional?

(edit add)  Also, whatever component that is next to U902 on B output board looks suspect, or maybe just dirty.

That B board had some bit of dust on it, I cleaned it up but don't recall that bit you identified. I'll go back and look at it.  The unit works perfectly from what I can tell.  I get my 7.5 digit back from calibration tomorrow so I'll check it against that. I'm happy its a fresh from the past unit that's not been touched.  I am going to put together a freshen up list of parts and get those Dallas units swapped out with some FRAM units.

And, I have to determine its place of honor in the home lab....

[Vince]

That Siemens motor (P/N 147-0035-00) is damn near impossible to find hence the high price from QService. The one in the 2465DMS shown in the picture was noisy and I was able to lubricate it and it's been quiet. But the Siemens motor in my 2465 no option shit the bed big time.
At that time I didn't realize that 400 series scopes use the same motor. So if you find a scrap 465/475 you can salvage the motor.

Thanks Papa Smurf, I take good note of that...

[tverbeure]

Electronics flea market loot.  A TDS 220 scope for $25 and one HP 5260A frequency divider for $30, but I was forced to take all 3 for that price because "only one is working and I don't know which one."



The TDS 220 works mostly fine, but the power board is drenched in capacitor electrolyte.



Once in a while, I also get this when connected to the probe compensation output. It's probably the well known BNC connector issues.



In other words: I bought myself a new project!

I expect that I'll be using this little scope more than my boat anchors...

[TERRA Operative]

I love these TDS200 scopes. I recently sold all four of mine though as I just don't have space.
They still get a decent price here in Japan with a test report (I used the Performance Verification software by Hakan Hintze).

What is cool with these is that if you have a communications or maths module fitted (TDS2CM or TDS2MM), you can run them through the adjustment procedure in the scope itself with no need for a PC or special GPIB hardware like the TDS500/600/700 scopes.

The TDS 2CM module can also be upgraded to a TDS2MM with a larger RAM chip and an EPROM with the TDS2MM firmware, I made a video on youtube about it if you are interested.

The BNC jacks are still available from Digikey and Mouser too, and on the earlier units you can upgrade the firmware simply by flashing a new EPROM and popping it in.

Yoirs seems to luckily have a good display (these often suffer from deteriorating polarisers) but replacements are available on aliexpress that work well if needed.

Keep us updated on your restoration, I'm more than happy to tell you all I know about these scopes.

[rdenney]

Haven't powered them up, yet. But I think (hope?) this will be the last test equipment acquisition for a while. This should fill in the gaps I had while still scratching the itch for the wonderful old HP stuff.

Yes, I had already acquired a HP339A distortion analyzer, but when it arrived it was so beat up I was afraid I would not be able to get it working properly. I pulled the trigger on an HP8903B, figuring I would throw the lesser of the two on the trade pile, but this one works so differently I think I will keep it (assuming it works or can be made to do so) and enjoy the 339A's oscillator source for other activities. For example, I could see mixing the two oscillators for an IMD test using an FFT display. Oscillators this clean are worth keeping.



To take advantage of the programmability of the 8903, I have also acquired an HP 82350B PCI HPIB card and five HPIB pass-through cables. If I can figure that bit out, my plan is to run the Keysight I/O libraries, WinGPIB, and Pete Millett's 8903 automation program. I'm replacing my main photo-editing workstation which will free up an old Xeon workstation-class computer that I can move to the shop.

And I've always been interested in FM radio, for some dumb reason, and have a bevy of tuners that are oldish and potentially in need of tuning up. They are all solid-state and most have digitally synthesized VFO's, so they may not need anything, but at least I can confirm that. And I can start trawling the local marketplace for restorable stereo junk to repair and sell if the motivation strikes. To that end, I picked up this Leader 3216 FM stereo generator. I think it will be pretty handy coupled to the distortion analyzers. These seem similar to Panasonic and especially Kenwood units of similar function, making me wonder who actually made what, or if they all just copied each other.



That sale came with a Leader LDC822 counter without the option. I already have a Tektronix CFC250 (made, I think, by Kenwood), which is probably in the same class, and an HP5334B, which is far better. This one does not appear to have the OCXO, and the specs call for a standard ceramic crystal accuracy of 5PPM. That's not really quite good enough for calibrating ham radios. But I can tweak it up now that I have a GPSDO reference (and a 5334B validated by that reference). Either it or the Tek will go, unless I find it useful on the ham radio table somehow. The word is out on the 3216 and the cheapest examples are uncommon--I certainly didn't get a screaming deal on this one--so selling one of these counters wouldn't bring much but it would take the edge off.

It is nice looking, though.



In other news, I have figured out which 200K precision resistor is bad in the highest decade of my General Radio 1434B Decade Resistor reported upthread, and have ordered a replacement. I went through the servicing procedure and except for that resistor it's exactly on spec.

Rick "still looking for the bottom of this rabbit hole" Denney

[wkb]

"Is that you down there?"

[rdenney]

"Is that you down there?"

You have to be looking back up to see that image.

Rick "still digging?" Denney

[Robert763]

I've done it again. Bought ANOTHER AC DC current clamp. Worse it's ANOTHER HEME 1000. That's 5 (plus a couple of spares units.
It did come with the leather case and 'scope output lead. The big positive is it was only £1.75 
I then did a search for them to see what others were asking for them (£60-160) and found a copy of the service manual. I had to have that even though it was 3 times the price of the meter...
They are very nice, auto-ranging 0-200 or 0-1000A Dc AC (TRMS) and with RMS and instant (AC / pulse) outputs.

It was the Dunstable Downs radio car boot sale on Sunday. I had a quick visit as I had a family commitment early afternoon. Not  lot of TE some expensive HP kit, I did miss (only just in one case) a couple of items. Not cheap but OK prices, a HP N SNA cal kit including 909A male and female loads for £100, and a 437A with two heads, lead and reference attenuator for £350 and a chinese copy of a Emco unimat lathe for £50.
What I did buy were a pair of Schaffner NSG 430 ESD simulator "pistols". Obvously been in storage for years but they were complete in cases and both work  absolute bargain at £20. Also got a Marconi 6587 levelling amplifier to add to my "real" VSWR measurement setup.
Also a box of bits that included two VeEx CX100+ CATV testers amongst some GPS receivers.. These have a 1MHz to 1GHz Spectrum analyser. As usual these were ex Virgin an locked out because they hadn't talked to mothership in a while. I know how to unlock them  . Both work fine. Also picked up a couple of smalls that I was specifically looking for including a specfic Nokia loudspeaker from a hands free kit. So overall OK. I studiousl ignored the boatanchors and "free" stuff.

Robert.

[factory]

Electronics flea market loot.  A TDS 220 scope for $25 and one HP 5260A frequency divider for $30, but I was forced to take all 3 for that price because "only one is working and I don't know which one."




I expect that I'll be using this little scope more than my boat anchors...

Nice find with those 5260A, hopefully the two faulty will be repairable, something like a PSU fault would be better than a dead front end, there is always a risk someone overloads the front end of TE with high frequency inputs (both old & new).

The fan seems kind of pointless in the 5260A, as everything in inside the cast alloy block.
Have you got a 5245L to use with them?

I've kind of got part of the 5260A, as it was used in this 5240A, still not got round to working on it, we can't access the mill to modify the replacement side, my fault for having too much TE. 



David

[factory]

The TDS 2CM module can also be upgraded to a TDS2MM with a larger RAM chip and an EPROM with the TDS2MM firmware, I made a video on youtube about it if you are interested.

Is there some reason why these modules are so overpriced? the TDS2MM & TDS2MEM* for example, are over £100 from feeBay sellers, there seems to be no shortage of them advertised either. 

*for TDS1000/2000 series.

David

[TERRA Operative]

The TDS 2CM module can also be upgraded to a TDS2MM with a larger RAM chip and an EPROM with the TDS2MM firmware, I made a video on youtube about it if you are interested.

Is there some reason why these modules are so overpriced? the TDS2MM & TDS2MEM* for example, are over £100 from feeBay sellers, there seems to be no shortage of them advertised either. 

*for TDS1000/2000 series.

David

"Just because" is the reason.... The usual overpricing bullshit.

There was a guy (he was on these forums actually) selling USB version modules on ebay, not sure if they are still available?

[Zoli]

...
There was a guy (he was on these forums actually) selling USB version modules on ebay, not sure if they are still available?

The guy published the design files(Gerbers, PLD):
https://www.eevblog.com/forum/testgear/enable-fft-function-on-tds210tds220tds224

[TERRA Operative]

Looks like it's the TDS2MM but without the communications function, There was a design made with USB port too, but I don't know if it was released.

[factory]

The TDS1000/2000 series has the extra measurement functions, a comms-less board isn't any use for my 2014, the main use is to get the scope to re-identify as a higher bandwidth model, really would prefer non USB based comms too.
Really not bothered with those on feeBay, as they cost more than the scope did.

David

[tverbeure]

What is cool with these is that if you have a communications or maths module fitted (TDS2CM or TDS2MM), you can run them through the adjustment procedure in the scope itself with no need for a PC or special GPIB hardware like the TDS500/600/700 scopes.

Yeah, it came with the TDS2CM and I have the components in a Digikey list to upgrade it to a TDS2MM.

I have a GPIB dongle, but I wasn't aware about the adjustment procedure. I'll need to read up on that.

Yoirs seems to luckily have a good display (these often suffer from deteriorating polarisers) but replacements are available on aliexpress that work well if needed.

After booting up, there are occasional flickers on the screen. I don't think it's the backlight, but the LCD panel itself. They go away quickly after warming up. The seller told me about it and thought it was related to the leaking caps, but I have my doubts... And right now, there's really no reason to replace it.

[m k]

Brightness control?

Laptops have cable problems, but they are usually less steady.

[tautech]

Yoirs seems to luckily have a good display (these often suffer from deteriorating polarisers) but replacements are available on aliexpress that work well if needed.

After booting up, there are occasional flickers on the screen. I don't think it's the backlight, but the LCD panel itself. They go away quickly after warming up. The seller told me about it and thought it was related to the leaking caps, but I have my doubts... And right now, there's really no reason to replace it.

Didn't these old TDS200 use CCFL for backlight ?
Maybe an upgrade to LED could be considered ?

[TERRA Operative]

Yep, they use CCFL, and LED upgrade is possible.
I never did the upgrade, and I always wondered if the noise floor would lower if the CCFL driver was to be disabled and replaced by a linear regulator for LED's.

There also might be a few small electrolytic caps on the LCD panel, but I can't remember.

A couple of my TDS200 scopes had leaky caps on the PSU, but after replacement with low-ESR, high ripple rated caps, the scopes were rock solid. Even found the noise floor was lower after the replacement due to lower ripple on the supply voltages.

[tautech]

Yep, they use CCFL, and LED upgrade is possible.
I never did the upgrade, and I always wondered if the noise floor would lower if the CCFL driver was to be disabled and replaced by a linear regulator for LED's.

There also might be a few small electrolytic caps on the LCD panel, but I can't remember.

A couple of my TDS200 scopes had leaky caps on the PSU, but after replacement with low-ESR, high ripple rated caps, the scopes were rock solid. Even found the noise floor was lower after the replacement due to lower ripple on the supply voltages.

IIRC TDS200 CCFL supply was direct from the PSU whereas in later designs it was from a separate inverter often with current limiting for when CCFL tubes failed/went outta spec.....or has it been too long since I had one apart ?

[tverbeure]

Nice find with those 5260A, hopefully the two faulty will be repairable, something like a PSU fault would be better than a dead front end, there is always a risk someone overloads the front end of TE with high frequency inputs (both old & new).

The fan seems kind of pointless in the 5260A, as everything in inside the cast alloy block.
Have you got a 5245L to use with them?

These 5260A were a case of "I have no idea what I could do with this, but $30 for 3 is too cheap to let it pass." They will probably find their way back to the same flea market in a few years...

I haven't powered them up yet, and I definitely don't have a 5245L. (I wish!) But I have a small platoon of frequency counters so I should be able to play with it.