Next: The tunnel diode oscillator.

Another point: The military hasn't dumped surplus equipment by the shipload since the '40s. J.I.T manufacturing and less on shore electronics manufacturing has dried up the flow of replacement inventory. Companies shed so little surplus that it's easier to let an employee or radio club have it, then they can sell off what they didn't want.

I recently bought a Tektronix 2465 for some knobs and shaft extenders on Ebay for $66 + shipping. The damn thing worked when I fired it up, so now I need even more knobs. The CRT is a little weak, but still quite usable. :)

Might find what you need here

The 366-2049-03 knobs always break on those scopes. They're $15 each, though...

What often breaks is the delayed-trigger clutch. One of the very few design flaws in this scope series, they made the plastic too thin. But all it does is operate an internal slide switch, so one could kludge a fix. A client found a guy in Greece who seems to make such knobs and ordered a whole new set. That made the scope look really nice.

Sometimes I need to build some interface right away, as in today. It has to be decent looking. Then Radio Shack can still save the day. I usually have all the parts I need but not the enclosure, connectors and such.

They are fun to work with and results can be mystifying - especially if your FM band amplifier decides to also oscillate (say) in the

All this talk about buying parts brought back some memories. When i was a kid i frequented Sunnyvale Electronics. At about age 14 i learned how to do will call at the "local" Newark in Mountain View (about 10 mi on bicycle). Call them up, work through the parts list, they give you an order number, write it down carefully, jump on the bike and it is ready by the time you get there. Pay cash. Take parts home.

?-)