Test Equipment Anonymous

Here's a rare one. A Dumont 2100GA portable scope. Dumont Labs was bought by Fairchild in 1960 but the writing at the bottom of the scope says "Dumont Oscilloscope Labs". I've never seen or heard of any Dumont scope much past the early 1960's. From what little info I can find this one date...

This Scott 330C has a three position wide/normal/narrow bandwidth selection that would be interesting to hear an AM music station through. I'm thinking about pulling it off the shelf and doing a restoration and alignment on it. Does this sound like a good fall project? Excellent Fall project. But b...

I'd rather find a precision ACV cal source at a reasonable price. Good luck.

Finally got around to checking the calibration of the 175. It sat for 3 days straight powered up due to a distraction of working on Blondie's Honda Accord. It had an electrical issue which took some time to fix. I'm getting too old to be bending under the hood of a car and my back is letting me know...

The 175 has been re-capped. Reassembled and will burn in for 24 hours then verify calibration.



The banished to the trash.

I wonder how many times cats have gotten the blame for things they've had no involvement with? I know mine got blamed for a number of things that I later found out he wasn't responsible for. He never got into the test equipment but kitchenwares on the other hand... I cannot leave TE disassembled on...

Put back together and neat and tidy. So OK, I'm anal. We all have our faults.

Is the British bond system still based upon a lottery or is it now interest based like US savings bonds?

Things that go bump in the night. Last night I hear this loud crash coming from the lab. What did the cat get into now? :o Go into the lab and find my custom made probe rack on the floor in a twisted mess. And several pieces broken off the probe rack. So today repaired the rack and untangled all the...

BU508A wrote: ↑Sat Aug 10, 2024 6:55 pm

Sorry, seems I have taken a wrong turn (179 vs. 175)

Summertime needs to be ending, it is too hot.

Since both are Keithley's I decided to add to this thread rather than start a new one.

Zenith wrote: ↑Sat Aug 10, 2024 12:52 am Excellent! Although I must say I prefer LEDs to an LCD.

Agreed. And no backlight is provided which makes it hard to read in low light conditions. I have the same complaint with my Fluke 8010A and 8050A.

Rather than start a new thread I'll continue here. The Keithley 175 is here. In VG condition and initial checks of DCV and Ohms shows that it's spot on. I'll be doing my usual clean up and re-cap. While I'm not thrilled with the brown case it will remain as is. At least it's much better than the awf...

Decided to make an offer. We'll see.

There's a Keithley 175 on my local CL about 15 minutes away from a seller I've done business with before and he's legit. Price is good and supposedly works. Can't make up my mind to go for it or not. I have plenty of DMM's here but no Keithley's. Did I just say that? :lol: https://hudsonvalley.craig...

Finishing up this project. I made an executive decision to not replace the capacitor shown, plus one under it, on the TM503 supply at this time. In order to get the old ones out it will take major disassembly and lots of cursing to get the tabs unsoldered from the board. I have replacements in stoc...

Finishing up this project. I made an executive decision to not replace the capacitor shown, plus one under it, on the TM503 supply at this time. In order to get the old ones out it will take major disassembly and lots of cursing to get the tabs unsoldered from the board. I have replacements in stock...

You will pick up noise and fuzz up the trace with the cover off. I speak from experience.

Re-cap and initial check out of the PS503 Power Supply. Re-capped. https://imagizer.imageshack.com/v2/xq70/923/yrRTCg.jpg After replacing the electrolytics and before replacing the tants decided to do an initial test. The supply came up fine, for about 5 minutes, then the positive supply went into c...

Keyboard jam?

Chris, I never got any warnings on the phone that the battery was failing. The only indication I got was when the rear cover seal broke.

Surprise and a close call. This is my Moto 2021 Android phone. The rear case started separating. And the reason is clearly visible. The Lithium battery has swelled. Holy shit. :shock: I bought a new phone today. I'm leaving the old phone powered up but NOT charging until the battery goes completely ...

The calibration of the FG501 went smoothly with just minimal adjustments required. This unit is now done. https://imagizer.imageshack.com/v2/xq70/923/ZGV2gp.jpg Some sample waveforms. The output impedance of this function generator is 50 ohms so the 2465 vertical was set to 50 ohms. https://imagizer...

Re-cap of the FG501.




The vanquished.



Next step is final calibration.

I had the same issue (twice) with the HV divider resistors in a B&K 2120 20MHz scope.

Back on topic. Working the FG501 Function Generator. Checked the internally generated supply voltages and both the +17V and -17V were reading about 5.09V. U430, a 741 op amp, was dead. Replaced it and now voltages are correct. https://imagizer.imageshack.com/v2/xq70/922/zoAvQE.jpg We now have an out...