Tektronix 2465B Oscilloscope Calibration Issues: Re-Powering the DS1225 (2013) [pdf]

A few years ago I almost got myself into beying a 2465B as it has 4 channels at a decent bandwidth. But I reconsidered, partly due to the BBRAM and U800 dying issues mentioned here, and got a Siglent instead. I kind of miss the cold war aesthetics of those old scopes though.

And i think this is the highest end monolithic real time CROs out there. The Tek 7104 goes up to 1 GHz but it is powered by plug in modules. And there is this sampling head with tunnel didoes that captures signals up to > 10 GHz.

I am really astonished by what Tektronix achieved half a century ago...

The Tek 2465B is the pinnacle of CRO (cathode ray oscilloscope) technology. It uses something called a “micro-channel plate” in the electron beam path inside the CRT. This device acts as an electron multiplier (electron equivalent of a photomultiplier) to amplify small signals. This makes it much easier to see transient events in single-sweep mode.

The downside of the MCP is that it makes it much easier to get phosphor burn-in if you’re not careful about adjusting the intensity down as low as it needs to be for your choice of time base. The CRT itself is also just much more difficult to replace because it’s specialized to just a couple of models.

These scopes were considered "instruments". Solid, precise, repeatable measuring devices. I have calibrated / adjusted / repaired probably a hundred of these. PMEL.

But, in 2023, $500 will buy you a good scope. It is really a USB interface for an ADC, but it is very usable. And will do things like decode digital protocols.

Design and repair of analog circuits is not as big as it was before the computer revolution.

All this old stuff is solid. HP generators and analyzers are top shelf.

But they are collectors items. Use the new, cheap throwaway test equipment on the new, cheap throwaway electronics.