I went to a local electronics flea market recently, and came home with a couple pieces of gear that will be good additions to my test bench:

First up is the HP 53181A Frequency Counter, 0-225 MHz, 2 channels, and some basic math functions built in along with an external reference input. Seen here after powering on and warming up for a few minutes, measuring my GPSDO clock reference – spot on! Not bad for $80.

Then there’s this Tektronix 434 Storage Oscilloscope. This one was free: another patron at the flea market purchased it while mounted to a Tek scope cart, but only wanted the cart. It’s dirty, both outside and inside judging from the noisy and sticky controls, but it powers on and displays a trace. It’s a “storage oscilloscope” where there’s an extra set of grids that absorb a charge from the electron beam and reflect it onto the phosphor, giving a primitive view of where the beam has been – and accounting for the splotchy appearance on the screen. I think something is stuck with that circuitry, because it showed a clean trace the very first time it was powered on, but ever since it’s behaving like this.

The Tek 434 was a portable scope produced from 1971-1984, and it used an early switching power supply that’s basically impossible to service if it goes bad due to using a bunch of custom transformers and a custom controller chip. I’ll probably clean and recap this one eventually so it doesn’t die. That’s a low priority project, though: this is a pretty low-bandwidth (24 MHz) scope, and I already have a Tek 465 analog scope, plus an older 2-channel and a newer 4-channel Rigol digital scope.

I just need to find a decent spectrum analyzer, and that’ll be the last piece of gear I really need for the bench to do just about anything.