Test Equipment Anonymous

I'm lost for words, a shame that ChatGPT wasn't. "Item description from the seller The Hewlett 83711b Packard Synthesized Cow Generator is a unique and innovative product designed to convert organic waste into clean energy. With the brand name Hewlett known for its quality and reliability, this...

I wonder if the missing components provide a V & I measurement capability? Seems very likely, the command decoding arrangement looks the same, I didn't try playing "guess the ADC" but I did search the web for a Farnell supply that had V & I measurement to see if I could work out w...

Yes, it seems fine now, though I haven't replaced the "remote" LED (one of the leads fell off during reassembly), so it's not perfect. It's better than specified for harmonics currently so I'm going to leave the filter alone. VCO voltages are within the limits in the manual and it's lockin...

Mouser delivered my parts (well FedEx, really), so the proper diffuse green LEDs are in, switches freed up a bit (though unfortunately at a cost of a bit of plastic snapping off and one of the switches is now drooping slightly but it seems to be cosmetic), brand news 4041UBE fitted and bonus surpris...

Another item from the DDRC boot sale, this is the usual Farnell 30V 2A power supply in an unusual IEEE488 equipped form. I like the Farnell PSUs and it was £5 and have a use for another programmable supply so I bought it. IMG_3309.jpg When I got home I discovered that the internet had never heard of...

This morning I measured the OCXO's current draw while watching the frequency on the counter, my theory that it was cold was wrong. It's actually really well insulated and even after the specified warm-up time the outside of the oscillator remains cold. It runs from 5V and the cold current is 450mA, ...

That is perversely awkward! Oh yes, but not if you treat the whole instrument as a warped test. Want to remove the front panel eh? That'll be remove rear chassis, the top and bottom panels and slide the side trim back to reveal the front panel screws, then remove the attenuator knob and the RF outp...

The filter alignment is quite simple on paper, the HF end uses two variable inductors and the LF uses variable capacitors. There are only two things to tweak for each band and the suggested method is to connect a spectrum analyser with a tracking generator and then for each band tune for minimum out...

Heroic indeed! That logic implementation is interestingly old-skool! I wonder if they really did it to keep the noise down? Conceivable, but a bit perverse. It's the only reason that seems realistic, according to a few replies I got on Mastodon or Bluesky this was built for EMC performance above ev...

As I was preparing to leave the DDRC rally I thought I'd take a look for some tantalum capacitors so I could repair a RACAL-DANA 9084 that I hadn't bought yet. It's always nice to combine two rally buys like that. Having spent £17.50 on more capacitors than I really needed in not quite the value tha...

I had avoided reading this thread in case I ended up with a Fluke 760A (No chance of that now.) but I'm glad I read it this morning, it's very interesting. I can contribute StereoDataMaker , a project that overlaps slightly with CHDK . You get two identical Canon cameras, apply software tweaks that ...

Had a think about this. The symmetry issue is strange given the symmetry of the schematic! I reckon R12 and R34 would be fairly critical, being four times larger (together) than the VR that adjusts symmetry, they''d only need to be 20% off in both cases to make the VR''s job very tough. But I reckon...

The little 335 waited for me to post it to the facebook VETE group and then expired quietly while I wasn't looking. This time it was a CA3046 doing what old CA3046s do and one of my new old stock parts has brought it thundering back into action. U700 if anyone is playing at home. I did consider chan...

I made a silly error during repair, a zener transposed so it because a 0.65V reference instead of 5.1V. I had to dismantle almost everything to remove the low voltage regulator board so I could not only correct my mistake but test the board independently of the scary 2,000V supply. https://live.stat...

The manual told me to remove the wrong screws, which was annoying because it caused the EHT multiplier to fall out and the captive nuts aren't fully captive - luckily they didn't roll out of sight. I should've spotted the mistake, really. These are the connectors that need to be reconnected when I p...

I bought this early 1970s portable from Sony/Tek on Sunday for £10, because it was looking very sad. I wasn't expecting to get it working but after a lot of cleaning it was apparent that it had two faults, the front panel had taken an impact and was distorted around the trigger control switches and ...

On the subject of GNSS, my Bodnar gps locked oscillator has new firmware which defaults to a mix of US and Russian satellites, choosing not to involve China or Europe. The old firmware didn't use the Russian constellation but did use all the others. The chipset can support multiple constellations bu...

I must say I admire your dedication. It doesn't make me more inclined to be drawn into the world of HP 85XX, but it is admirable. They're strange systems, there's a mix of brilliant design and not so good design. This evening I've run into an issue with the labels, it seems the 8501A is not making ...

Update!

I spotted an ebay listing for the cable that connects the 8501A storage normalizer to the 8505A, it was £40 but they're quite rare…

It arrived and after a bit of jiggling of the innards of the 8501A it is working. Wobbly video link below.

https://flickr.com/photos/synx508/54178653351/

I panicked, perhaps, I think it's still settling down.

And oh dear. I shall be contacting the company tomorrow as I suspect there's a problem, possibly just the active antenna though. It's flipping between being able to see 35+ satellites and use >12 of them and being able to see 20 to 23 satellites and being able to use 3 or 4. I tried substituting the...

I've now got a Leo Bodnar LBE-1420 and I'm pleased with it, very small, does what it was supposed to do, easy to get working. The output level's perhaps a bit excessive so I've reduced it with a 50Ω 6dB attenuator. It's also a square wave output which I've filtered into a reasonable sine, but I was ...

5335As were peak usefulness in HPs counter range. Nothing they did afterwards has the same flexibility. It's a shame they're so large, the box is mostly empty, too. If you want nearly the same stuff in a small box with fewer digits and a life of weird faultfinding then get a RACAL-DANA 1992 3325B At...

It's necessary for all TE forums to have a thread on 5335As, so here goes… aaaaaa.jpg Despite already owning two completely working 5335As and a third parts unit I decided I needed another, as the well known eBay test equipment scrap dealer had been reducing the price every few weeks for what felt l...

Thanks for the circuit diagram, I think I have a slightly different version from a different source. The white stuff is thermal grease that someone clearly applied enthusiastically, I've left this and not cleaned it up at all - the oven part seems fine. The problem was really just the rubber tube ar...