Test Equipment Anonymous (TEA) group therapy thread

[bitseeker]

  Light weight cardboard stuffed with peanuts only. Way to screwup a tidy bit of gear!

Ugh! That's a drag. Sorry, beanflying. Heavy items are so scary in the hands of inexperienced (to put it nicely) sellers. Hope they take proper care of the situation.

[beanflying]

The glow of semi accurate Nixies read with the help of unobtanium connections is helping the calm....  Ohm Ohm Ohm....

Can't find a good thread on these so one coming up.

[Cubdriver]

I need to come up with a replacement voltage reference for the unobtanium mercury battery that is missing from mine.  It's been sitting on its side in the hall forever.

Sucks that yours was damaged in shipment.  I wish people would learn to pack things, it's not that difficult a concept (at least I don't think it is...)

-Pat

[Brumby]

Ah .... isn't it wonderful to see the pixies in the nixies playing nice....

[beanflying]

Just something over the front of it would have helped 

As the HP has warmed up now sitting within 9mV of my 34401 and the GW121 off my noisy 12V fixed supply with a little needle bouncing. Dropped it onto a clean switchmode (oxymoron <5mV ripple) at about 12V for the same 9mV.

The quick peek inside looks good when I bodged the power into it, tiny smear of oil coming from most of the 'sealed' inductors it seems.

[neo]

Cheap resistor decade box, that i can't buy, here, https://www.ebay.com/itm/Ohmite-OHM-Ranger-Stock-3420-pre-owned-used-untested/132487515267?_trksid=p2485497.m4902.l9144

[beanflying]

Happy 50th Birthday for the 740B last May making it a full year older than me. Which of us will survive the longest and still be the most accurate. Does old test gear become more forgetful or just lose it's capacitance to continue working

Down under 7mV differential on the New toys.

[Specmaster]

Cheap resistor decade box, that i can't buy, here, https://www.ebay.com/itm/Ohmite-OHM-Ranger-Stock-3420-pre-owned-used-untested/132487515267?_trksid=p2485497.m4902.l9144

Why can't you buy it then?

[neo]

Cheap resistor decade box, that i can't buy, here, https://www.ebay.com/itm/Ohmite-OHM-Ranger-Stock-3420-pre-owned-used-untested/132487515267?_trksid=p2485497.m4902.l9144

Why can't you buy it then?

The wallet said that if bought one more thing this month i would be sleeping in the snow, what can i say? After seeing the bill if i win this nixie tube bench meter i believe her. 

[Specmaster]

Cheap resistor decade box, that i can't buy, here, https://www.ebay.com/itm/Ohmite-OHM-Ranger-Stock-3420-pre-owned-used-untested/132487515267?_trksid=p2485497.m4902.l9144

Why can't you buy it then?

The wallet said i bought one more thing this month i would be sleeping in the snow 

Oh, thought for a moment Ebay was dicking about again [emoji23]

[beanflying]

Look on the bright side at least your internal postal charges are a heap better than export. My freight bill alone in the last few weeks from evilbay is at least a months food.

Dried beans and lentils for the next few weeks ....... 

[neo]

Oh, thought for a moment Ebay was dicking about again [emoji23]

Their certainly good at that, but in this instance their not.

Look on the bright side at least your internal postal charges are a heap better than export. My freight bill alone in the last few weeks from evilbay is at least a months food.

Dried beans and lentils for the next few weeks ....... 

Very true, so very true.

[Specmaster]

Look on the bright side at least your internal postal charges are a heap better than export. My freight bill alone in the last few weeks from evilbay is at least a months food.

Dried beans and lentils for the next few weeks ....... 

That's a good healthy diet, all washed down with generous portions of lovely glow from LEDS and nixie tubes, what could be better?

[CatCow]

  Light weight cardboard stuffed with peanuts only. Way to screwup a tidy bit of gear!

Had something similar with a Fluke 6060B recently. Soft box, 1 1/2 loose wraps of thin bubble wrap, and a week in a FedEx truck. Bent handle, bent rack ear, and the corner of the chassis was pretty messed up. Also shattered the cooling fan in the back, and tore it off the anti-vibration mounts.

Then I find out there is no output below 245 MHz - well, there was something, just not what it was supposed to be. The output amplifier was working properly as I was getting the correct power output from the front up to a certain frequency, later found out that was because the bad mix was getting knocked out by the 245 MHz LPF. I narrowed it down to either the 800 MHz oscillator or the mixer stage, and had to visit a friend with better gear to look at it. Finally figured out that the 800M signal was WAAAAY too low(IIRC service manual says 0 dBm, was getting more like -34 and way low in freq). 3 hours later we finally find a short to ground that just shouldn’t exist - in the third pic you can see the VCO on the left, PLL is off screen on the right. R161/159 and L62 and C177 all shared a common connection where it seemed to be shorting out, and was right between the PLL output and the VCO input. My friend suggested reflowing those solder joints that were accessible(C177 would require removing the PCB), and all of a sudden it has output!

[Mr. Scram]

Oh bother. After months of waiting my TF930 finally showed up. My luck persists, as contrary to the other examples here mine is horribly yellowed and comes with various nicks and scrapes. Even the knob on the front is loose and scrapes against the case when turned. It must be one of the worst ones in the bunch, as it's as bad or worse than the "worst case example" in the ad.

I'm sure it'll be better when I let the disappointment subside, but at this point I'd rather just chuck it in the bin and forget about it.

[Specmaster]

Are you sure the heater isn't supposed to be left floating? You could experiment with an additional transformer to power your DC-DC converter and see if the problem goes away.

Considering how small your current requirement is, you could easily hand wind a 1:1 toroidal transformer to power from the heater transformer; or even a small AF DC-blocking transformer would probably work. If the DC-DC converter doesn't want to play nicely, a simple zener diode regulator circuit, or like I suggested earlier, a voltage divider across the output of something like an AM1117-3.3 linear which should keep your overall current draw down to a few milliamps.

mnem
Bees do not taste like honey.

Problem solved, it was the full wave rectification, replace that with a single diode for half wave, followed by that 1000uF 25v cap and bingo, everything works and not a hint of volt drop anywhere, all rail AC and DC rock solid, now to transfer it from bread board to pcb and install it.

[Specmaster]

Oh bother. After months of waiting my TF930 finally showed up. My luck persists, as contrary to the other examples here mine is horribly yellowed and comes with various nicks and scrapes. Even the knob on the front is loose and scrapes against the case when turned. It must be one of the worst ones in the bunch, as it's as bad or worse than the "worst case example" in the ad.

I'm sure it'll be better when I let the disappointment subside, but at this point I'd rather just chuck it in the bin and forget about it.

Oh dear so sorry to hear that, have you informed them of your disappointment, maybe a partial refund or something might help make you feel better about it? I have to say that I'm extremely pleased with my 2, their condidtion is as if I had brought them new in sealed cartons and just removed the plastic bag for the first time.

[Mr. Scram]

Oh dear so sorry to hear that, have you informed them of your disappointment, maybe a partial refund or something might help make you feel better about it? I have to say that I'm extremely pleased with my 2, their condidtion is as if I had brought them new in sealed cartons and just removed the plastic bag for the first time.

No, but I don't think it makes much of a difference. Their ad stated it was used and showed a yellowed example and that's what I got. Plus that it's not the money, I just want a counter in a decent condition. Even giving me back my money thrice over won't help that. Though shipping has taken ages, they've been very helpful otherwise. I don't want to complain about something they didn't even do wrong. They seem to be good people.

Considering all the luck you lot had with your pristine specimens, I had hoped for something better. Bugger. I'll go mumble bad words to myself in a corner now.

Guess I'll get to try the retrobright unyellowing technique.

[Specmaster]

Oh dear so sorry to hear that, have you informed them of your disappointment, maybe a partial refund or something might help make you feel better about it? I have to say that I'm extremely pleased with my 2, their condidtion is as if I had brought them new in sealed cartons and just removed the plastic bag for the first time.

No, but I don't think it makes much of a difference. Their ad stated it was used and showed a yellowed example and that's what I got. Plus that it's not the money, I just want a counter in a decent condition. Even giving me back my money thrice over won't help that. Though shipping has taken ages, they've been very helpful otherwise. I don't want to complain about something they didn't even do wrong. They seem to be good people.

Considering all the luck you lot had with your pristine specimens, I had hoped for something better. Bugger. I'll go mumble bad words to myself in a corner now.

Guess I'll get to try the retrobright unyellowing technique.

Post a photo here anyway.

[med6753]

Cheap resistor decade box, that i can't buy, here, https://www.ebay.com/itm/Ohmite-OHM-Ranger-Stock-3420-pre-owned-used-untested/132487515267?_trksid=p2485497.m4902.l9144

Why can't you buy it then?

The wallet said that if bought one more thing this month i would be sleeping in the snow, what can i say? After seeing the bill if i win this nixie tube bench meter i believe her. 

I'm so glad that I am the wallet and I answer to NO ONE 

[Specmaster]

Cheap resistor decade box, that i can't buy, here, https://www.ebay.com/itm/Ohmite-OHM-Ranger-Stock-3420-pre-owned-used-untested/132487515267?_trksid=p2485497.m4902.l9144

Why can't you buy it then?

The wallet said that if bought one more thing this month i would be sleeping in the snow, what can i say? After seeing the bill if i win this nixie tube bench meter i believe her. 

I'm so glad that I am the wallet and I answer to NO ONE 

You know sometimes its good to answer to someone, it does have its advantages as well. 

[AF6LJ]

  Light weight cardboard stuffed with peanuts only. Way to screwup a tidy bit of gear!

Had something similar with a Fluke 6060B recently. Soft box, 1 1/2 loose wraps of thin bubble wrap, and a week in a FedEx truck. Bent handle, bent rack ear, and the corner of the chassis was pretty messed up. Also shattered the cooling fan in the back, and tore it off the anti-vibration mounts.

Then I find out there is no output below 245 MHz - well, there was something, just not what it was supposed to be. The output amplifier was working properly as I was getting the correct power output from the front up to a certain frequency, later found out that was because the bad mix was getting knocked out by the 245 MHz LPF. I narrowed it down to either the 800 MHz oscillator or the mixer stage, and had to visit a friend with better gear to look at it. Finally figured out that the 800M signal was WAAAAY too low(IIRC service manual says 0 dBm, was getting more like -34 and way low in freq). 3 hours later we finally find a short to ground that just shouldn’t exist - in the third pic you can see the VCO on the left, PLL is off screen on the right. R161/159 and L62 and C177 all shared a common connection where it seemed to be shorting out, and was right between the PLL output and the VCO input. My friend suggested reflowing those solder joints that were accessible(C177 would require removing the PCB), and all of a sudden it has output!

ETA pics not working from iPad, will reupload in the morning when I get home.

I really hate to see gear damaged like that.. The person who packed the box should be packed up and sent across country like that.

[med6753]

Cheap resistor decade box, that i can't buy, here, https://www.ebay.com/itm/Ohmite-OHM-Ranger-Stock-3420-pre-owned-used-untested/132487515267?_trksid=p2485497.m4902.l9144

Why can't you buy it then?

The wallet said that if bought one more thing this month i would be sleeping in the snow, what can i say? After seeing the bill if i win this nixie tube bench meter i believe her. 

I'm so glad that I am the wallet and I answer to NO ONE 

You know sometimes its good to answer to someone, it does have its advantages as well. 

She has her own place. I have mine. She spends her money on clothes and shoes. I spend mine on TEA. No conflicts. No questions. Life is good. 

[Specmaster]

Successfully transferred the circuit from breadboard to PCB and installed, tested and calibrated, works like a charm, no more worries about battery leakage, especially as its a piece of equipment that does not get used all that often and judging by the state of some of them offered for sale on eBay is pretty the same for most owners. This one wont be suffering from battery corrosion in the future 

You can just about read the heater voltage on the HP 3466A (5.385vac) in the background while the F27 (1.504vdc) on the left reads the output from the DC to DC converter and the F27 (6.66vdc) on the right reads the half wave smoothed DC input to DC to DC converter.

Winner winner.... reading VAC, VDC and resistance all on the same jacks without having change input jacks just can't use the original Heathkit RF probe which would shared the DC i/4" socket with the DCV input, and as I don't have a probe, it would be safer to convert to a more conventional way of using a multimeter.

If anyone else is interested in doing a similar thing, the schematic below is a copy of the hand drawn battery replacement that Heathkit engineers designed and fitted to a lot of meters in the factory prior to shipping according an ex Heathkit employee. I did not use this method however, just dc to dc converter 5-6V in and 1.5v out and fed it with power taken from the same source as the alleged Heathkit drawing via a IN4001 and 1000uF 25VDC cap.

[Specmaster]

Cheap resistor decade box, that i can't buy, here, https://www.ebay.com/itm/Ohmite-OHM-Ranger-Stock-3420-pre-owned-used-untested/132487515267?_trksid=p2485497.m4902.l9144

Why can't you buy it then?

The wallet said that if bought one more thing this month i would be sleeping in the snow, what can i say? After seeing the bill if i win this nixie tube bench meter i believe her. 

I'm so glad that I am the wallet and I answer to NO ONE 

You know sometimes its good to answer to someone, it does have its advantages as well. 

She has her own place. I have mine. She spends her money on clothes and shoes. I spend mine on TEA. No conflicts. No questions. Life is good. 

Until somebody wants to have a closer relationship and then the shit hits the fan and suddenly TEA gets more complicated as a result