[R-390] 6C4-The Final Horse Beating?

[Ed Zeranski]

My little bit. Lets whup that horsies butt!!!

I've had several 'sticks' of new RCA 6C4s that developed fil-cathode type
leakage where the noise got worse as signal strength increased. It wasn't
the whole stick but 2 or 3 tubes out of 5, still a high count. The first
time it popped up was the OSC in an HQ-170-VHF. The 6C4s were boxed-NOS
given to me from a friends pile as thanks for re-working a Valiant.

EdZ