Testing tubes

[Philcofan42]

Originally Posted by gadget73

The high pitch whine sounds like oscillation. I'd check the wire routing, and ensure that the volume control itself is good. If its open, it could cause the detector to be unloaded, which will make it oscillate. Also make sure that all tube shields are in place. I don't know anything about this particular radio, but radios designed to use shields or metal tubes will get funny with unshielded glass or missing shields.

Well, I'm sorry to say I didn't take a good enough look at the tubes until now. Some were in the wrong sockets, one of the tube shields was in the wrong place and some are just plain wrong. I know nothing about which substitutions are allowed so here is the list of what's going on with my tubes now:

1st & 2nd I.F. - both correct at 6U7G
Det-AVG - correct at 6J5G
Rect - should be a 35Z6G but is an 2576GT/G
Output - Should be a 25C6G but is an 25L6GT
A.F. - correct at 6F5G
OSC-Trans - no longer has any markings, but should be an 6K8G

Thanks again!
Dan