If you are seeing blown tantalum caps carefully test the main power supply for excessive ripple, if there is too much ripple it stresses the tantalum caps and causes them to fail sooner.
Sometimes I hook my cans up to B+, and dangle the ins and outs to the analyzer/counter/generator/etc. to see if it makes sense. Good work! You are brave! Not to scare you, but it has 5 PLLs. They actually are quite fixable. Mine's still humming out it's phase noise rich sinewave. 73's! W3IHM
1. As you will discover soon enough, Wavetek had a near 100% failure rate with those tantalum capacitors. The smell of the recently dead cap is truly memorable. In the Wavetek test gear, it's the gift that just keeps giving. 2. Next major problem: +/-18V rails. These power most of the opamps. But this is at or beyond the absolute max supply voltage for those opamps. Wavetek: Designers for Disaster. 3. Construction method is what's possibly ok for prototyping, not production. What a total mess.
I recognize those little Teflon solder cups from a military ADF program I worked on back in the early 80's. Very similar construction techniques. Those tantalum teardrops caps have been a real issue in some of my old test equipment I have. They will just short all of a sudden and send that supply into protection or sometimes just take out the series pass transistor like a fuse. I've just went thru and replaced them all figuring if they made it 40 years I'll be gone before needing replacement again. 🙂 👍
Looking at the solder-blob circuits inside of this Wavetek reminds me of when I worked for Anritsu during the 90s. It was common practice to create synthesizers in dead-bug form. In those days engineers had their own workbenches in their cubes - with soldering irons and whatever lab equipment needed. This facilitated a creativity that has seemingly vanished in modern companies.
Whole pile of cool stuff there, and built to last, must get round to fixing the keyboard fault on my Marconi 2019, looking forward to seeing your wavetek up and running.
Wow, that's some amazing construction. Truly hand-crafted, artisanal test equipment from the "good old days." So many things going on, so many trimmers here and there, too.
Can you 1. Measure resistance of the dead Tants. 2. Measure the DC resistance of each module to see if there is a dead Tant in or something else shorting the DC input?
Turns out I will be back on my home turf in Palo Alto next week. I am planning to stop in to your favorite electronics store (Anchor Electronics) while I am in the area. Back in my day it was Red Johnson Electronics in Palo Alto and Haltek and Halted Electronics in Mountain View. All those are gone now.
red johnson before my time, but loved spending hours at Haltek. there were half a dozen others with names I've forgotten, or maybe they didn't have one. You just had to know where to look.
