Electronics Test Equiptment

[WhiteWarlock]

Eico Model 377

[WhiteWarlock]

R.S.R. Electronics 234a

[WhiteWarlock]

[WhiteWarlock]

[WhiteWarlock]

[NoiseWiki]

I think I have one of these

[crochambeau]

I'm so glad I stopped collecting old test equipment before Hainbach drew attention to it.

There are still a few items I will avoid mentioning because I'm a curmudgeonly old fuck and I want the opportunity to buy spares without spending popularity pricing.

The Eico 377 is nice, sort of the pauper's HP-200 (but with SQUARE!). Tubed.
The Eico 378 is sort of the pauper's 377, stepped controls and loss of square (WHY WOULD THEY DO THAT?). Tubed.
Eico 488 electronic switch is nice for ultra choppy tremolo, or switching channels back and forth at speed. Tubed.

Heathkit also has versions of all of this stuff, but I sort of fell on the Eico side of the fence based on an earlier love affair with their amplifiers (discussions for a different thread).

Beware of original purpose, usually decipherable based on frequency ranges. There was a lot of (more than audio?) test gear built for radio and TV, and those signals often need a bit of "assistance" for direct work in audio ranges. Sometimes modification can be had with some internal value adjustments, but often the active elements, interstage transformers, etc. are not selected with mind bogglingly low frequencies (with respect to radio) and are not as glorious as one would hope.

Old Tek scopes are often too heavy to ship (I have one that weighs something like 95 pounds, I know - I bought it by weight) and have been crazy cheap in the past (I should widen this to scopes in general, but I only write about that which I have had hands on experience), look for something with a "vertical out" tap. Example, the 545. This will allow audio passage through the often modular preamplifiers. Take something like a type 53/54 or CA plug in (I think one of those is a tube/transistor hybrid, but I don't feel like pulling to modules to find out which is which) which (hah!) is a "dual trace" plug in, or a far more sophisticated electronic switch than the Eico 488, and you can sync the switch with horizontal refresh with itself can be driven from an external pulse/signal.

Mind you, these are tubed, and often need a healthy external signal. Example:

I know Hainbach posted a video in which he was using the Tek 161/162 (might have been a 163 in there as well, which can provide a shorter pulse, which is not as lush for audio); the 161/162/163 are simply function modules for the 360 o-scope system. I notice he was not exploiting external sync, which needs something on the order of 20 volts to trip. I have plugged the speaker outputs of 50-100 watt (SOLID STATE as we're working into high impedance here, and as usual it's best to know if your given amplifier topology can do unexpected things of it - I don't and will not be blamed for any BBQs that happen by following paths I speak of) amplifier, and driven the 162 waveform generator (that is driving the pulse generators with a roughly 70 volt sawtooth) via any bog standard audio. Tons of fun, I'm sure anyone can run this idea farther along without my spelling it out.

Apologies, I'm sure that reads like a mess. I'm not fixing it.

By now, pretty much any old tubed stuff is going to want a proper service, which can cost hundreds if you don't DIY.

[WhiteWarlock]

Your post makes total sense for me & was highly informative/entertaining reading...
Personally had no clue who Heinbach was until semi recently... trends... whatever...
hmmm been into test gear for ages for practical & experimental purposes...
plus test gear tends being so hot as audio oscillators with that pure authentic vintage sound...
also my old mentor got me hooked on his vintage RCA "lunchbox" Audio Generator...
anyways... tend using Heathkit sine/square... since have 4 of them