Old tube Tek sig generator - what's good in there?

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My best dumpster dive at the recycling center for years.... an almost intact Tektronix 50TU tube signal generator. I can't find a schematic for it. Not sure of age except that it pre-dates the "modular" Tektronix designs. A square-wave generator, time base generator and crystal-controlled RF source, but all integrated into one BIG box. I plan to scrap it (but if this item is valuable maybe not...)

Lots of nice knobs and switches. A bunch of selenium rectifiers that I'll toss. A big blue power tranny. And LOTS of small signal tubes, maybe a couple dozen.

How likely are the tubes any good?
While I'm familiar with virtually all of the old Tektronix equipment, I've never heard of a 50TU generator. Either you have a custom (never marketed) in house piece, or something extremely old, or the wrong number. Although the blue color does set a date limit. My catalogs go back to the late 50's. Can you post a picture?
As I think about it more you probably have an in house "test unit" that was never offered for the public. It may be a collectable worth some money as it is.
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Here are some pictures.

12 x 5965
12 x 6AL5
13 x 12AU7A
6 x 12BY7
6 x 6AU6
and some others...


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Wow, so cool. :cool: Definitely an in house piece. Tek and the Government are probably the only ones that ever had one. A typical giant footprint of the time. The signal generator needs a special attenuator head that feedback is taken from to assure a level output at the connector just like the Tek 190. The 5965s are better versions of the 12AU7 with slightly higher heater current. They were meant to withstand cathode interface degradation from long off periods. I'll bet they are in the time mark section.

I can see that the ceramic connection strips are the push in style verses the earlier threaded stud type. This puts the date around the late 50s to early 60s. If you reuse these, solder and unsolder quickly lest you damage the bond to the ceramic. That's why Tek used low temperature silver bearing solder.
I agree that it seems a shame to tear down such an unusual item. I'll keep it intact if and until the urge to yank out that transformer is keeping me up at night. :D

I'm going to see what things like it sell on e-Bay, but frankly I've already worked it out as worth a couple hundred dollars in parts if I used it that way, so I'd have to set a pretty high price.

Anyone have an idea of how much life the tubes may likely have left in them? Without a tube tester is there an easy way for me to check with an o-scope, signal generator and multimeter?

Not sure if you're in Portland, but I do wonder if the guys at Tek up in Beaverton might be able to help you out with some extra info about this very cool piece of equipment.

I'm within a reasonable drive, usually taken so my wife and daughter can go shopping in the "big city".

I sent a photo to the "discontinued products" support e-mail at Tek. If nothing else it should give them a laugh...
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