[ARC5] Reducing BC-459A chirp: 12A6 replacement for 1626

[Henry Mei'l's]

Found this in on page 64 of Hints & Kinks, Vol. 5 (1955)(WN7RKY). Screen grid voltage derives (from osc. anode voltage?) via a 20k series resistor, bypassed witrh a 0.001uF cap. This is supposed to reduce chirp.

(This mod is almost invisible mod and shouldn't cause too much consternation among the purists among us -- and it's easy to retro ;0)

Any one tried the this tube switch ?  

(BTW: On page 40, there is also mention of RF causing 1625 filament voltages to rise to 18-22 volts, cured by grounding to a copper strip running across the chassis and feeding filament voltage via RF-lossy microphone cable with bypass caps at both ends. This is probably old hat; just thought I'd mention it, anyway.)

73

Henry OZ1UF, Cph.