I'm in the process of "re-restoring" my RCA Victor television model 730TV1. I noticed that the set was had a 5U4G in the socket instead of the spec 5V4G. Are these interchangeable in a damper circuit?

I'm in the process of "re-restoring" my RCA Victor television model 730TV1. I noticed that the set was had a 5U4G in the socket instead of the spec 5V4G. Are these interchangeable in a damper circuit?

I've seen it done too! The 5V4 is an indirectly heated cathode. Heater is rated a two amps, where the 5U4 is three amps.
The power transformer has a separate winding rated at two amps, but insulated for the high potential found in the damper circuit.
Best to replace it with a 5V4G. :yes:

I believe the 5V4 has a lower drop and thus may do a better job.

I recall replacing 5Y3s with 5V4s to get more B+.