Test Equipment Anonymous

Trolling through Aliexpress, there's a large selection of various kinds of display. It can be a matter of finding one with the right form factor. It may be possible to use a larger one than the original, if there's room. There are libraries in C and Python for most of the chips the displays use. It'...

Displays in vintage equipment can be an enormous problem. Very often they are specialised VFDs or LCDs and the original is expensive or unobtainable. The design can be quite elaborate. Sometimes analogue meters can also be very hard to replace. There's a huge market for small modern computer display...

I feel your pain. That 465 I bought for a tenner appears to work. It was only a lazy attempt to put it through its paces, but a proper probe on the calibrator produces a passable square wave in both channels. I haven't checked the delay sweep. It seems a shame to use it as a parts mule. The Wavetek ...

I haven't had a problem with the Petolta connectors, mainly because they are open frame so you can see whether the solid core is entering the inner socket correctly. If that wasn't the case then it would be easy to push a bit too hard and terminally (ho ho) bend the solid core. Peltola, definitely ...

On balance I'm glad I didn't spot that one. I did come away with a Tek 465 which is still in the car. I've been investigating a Wavetek function generator which came from there. I always feel a sense of relief when those Peltola connectors fit back successfully. They look very easy to damage. I have...

Cat's melting - impossible.

Friends had two black cats who liked to get under the log burning stove when it was fired up. After a time, the heat got too much even for them, and they'd dart out with their fur smoking.

Satellites are well tracked as is space junk. Commercial airliners also usually fly on predictable paths. Military aircraft are a different, but much rarer problem. It can't be all that difficult to manage time on the telescope to accommodate these things. Anyway, large numbers of satellites have be...

Exposure take 30s, which is relatively fast: https://rubinobservatory.org/explore/how-rubin-works/numbers . Nonetheless there will be trails, of course. "Time on telescope" is a scarce resource, so I imagine people will be reluctant to take the same picture multiple times. But what do I k...

It's a common technique, and increasingly common in amateur astronomy, to take hundreds of exposures and average them to get rid of atmospheric distortions, aircraft, satellites etc. This telescope is on top of a mountain in Chile, so well above most of the atmosphere, and it's not clear how wide a ...

I'd feel a bit uneasy about the amount of beryllia myself. It's OK unless you break it up, but even so.

Are you giving it to be believed that you've got, what's generally accepted as a complete horror show, to work - for the immediate future? Let's gloss over the calibration with the special Racal case/calibration jig.

"You're a better man than I am, Gunga Din".

Although one expects elected representatives of the people to present their views in the form of intelligent debate especially in the highest court in the land, Parliament ! The reason that the UK government and opposition party's benches are spaced apart as they are, is that was considered to be t...

Farnell started as a components seller in the UK in the late 30s. They branched into manufacturing in the 50s. They made PSUs, audio signal generators, function generators and the odd oscilloscope. My impression of their products is that the PSUs were well thought of. The signal generators were mid ...

I'm a bit sad after receiving my spectrum analyzer: This kind of instrument was the pinnacle of my TE-dreams, the kind of sophisticated instrument I thought it would still last a long time to finally find and acquire a decent one. And now it's here. The dream is gone. :( On the other hand: I can ch...

It does warn of interaction, though, but this seems to be just between the two controls and not adjacent bands. Less simple in the practical sense because you can't tune it "live" as the adjustments are inaccessible when it's in its screened box and if removed from the box with an extende...

I feel I should mention that, as with other RACAL equipment that I've worked on, the RACAL soldering approach is "long bent-over leads with distorted ends that don't fit back through the very tight PCB holes so it's a good idea to snip the ends off or risk pulling the terrible through hole met...

Definitely character building, although I believe you could have talked the seller down to £10, as I doubt he would have wanted to take it home. Then you could have built your character for £15 less, which is also character building in itself.

Per ardua ad astra!

Calibration of the 5B13N Time Base. As mentioned before the trigger works fine in both Normal and Auto mode but there is no baseline free run trace in the absence of a trigger in Auto mode. The manual states there should be. There isn't. All the trigger functions are contained in one IC. Here is th...

MED6753 wrote: ↑Tue May 27, 2025 7:44 pm This CRT is not as bright as I think it should be and it exhibits double peaking which indicates lots of hours.

You're much better at pictures of oscilloscope porn than I am.

Zenith's second picture of his 8600 shows the same mains socket insulation made of perforated paper. So clearly it was an aberrant line rather than a specific meter :( That's fish paper - it's a vulcanized fiber material that's lightweight, tough and tolerant of temperature extremes, and has been u...

450V - 0 - 450V transformers with connections made to bare tags on top - no cover, no attempt at safety insulation. Live chassis TVs and radios........ Some people don't like the mains wiring going to the front panel switch on the 8000 and 8600, and mains voltages close to sensitive metering circuit...

Med's first picture of his 8600 shows an block of what looks like silicone sealant, between the questionable IEC socket and the mains transformer. I suppose it was put there for reinforcement.

There's no doubt that a few iffy design decisions were taken with these things.

Those piano key switches were a 60s and 70s thing. I find the keys on the 8800A a PITA altogether. They are very small and I find it easiest to use them with a pencil with an eraser on the end. This is not ergonomic design. As plastic ages it becomes brittle. They might at least have made the on/off...

The 8800A has piano key switches and the mains switch is at the rear and in a compartment. It's operated by a rod, which is moved by a lever arrangement from the piano key. The lever can come loose and is a bit fiddly to reinstall, but generally causes no problems.

It does indeed route mains to the front panel switch. They could have used a plastic shaft to activate the mains switch on this, but there is space left for various options such as a data output card and they may not have had room. The mechanical link to the mains switch on the 8800A is a strange th...