"Double Pulse Generator"

I have one made by "Advance", most of the transistors are early germanium and (I vaguely remember) some avalanche devices to give sharp pulse edges. They were exotic specialised equipment used mainly in the nuclear and telecommunications industries.

As far as I know, their main use was producing pairs of pulses close together to check that devices like Geiger counters weren't missing pulses due to latency. They could also generate test waveforms for video links.

Wow. Thanks, Liz.

I have a unit made by Lloyd Instruments England which looks like it dates from late 1970s/early eighties built using TTL chips. I bought it at a flea market intending to use for researching Weinberg topology switchers but so far I haven’t used it.

Not heard of Lloyds Instruments, Piglet, but there were *many* small manufacturers of electronic test equipment back in those days. The one I have is made by Venner, also in England back in the late 1960s. I just plugged it in - throwing caution to the wind - and much to my surprise, it

a) didn't blow up b) actually output pulses.

Not bad for something that hasn't been used for *many* years (if not decades).The only fault I could find is that it's only putting out negative-going pulses, but that's probably just a dirty switch. Obviously there's a lot of noise when the controls are turned and switched in and out. That's only to be expected with vintage stuff that's been unused for so long. If you're into vintage equipment, I also discovered a R&S field strength meter from about the same era. Not sure how much of a market there is for any of this stuff nowadays, though. So many useful gadgets coming out of China it's made a lot of old gear obsolete.