[ARC5] ARC-5 VFO question

[David Stinson]

Neil Barnett wrote:
> 
> In the ARC-5 transmitter, why is the return side
> of the 1626 heater connected to the (cathode) tap
> on the oscillator tank coil?

This is designed to put the cathode and 
heater at the same RF potential, thus preventing
drift due to thermal motions of the heater
and heater variations from tube to tube.
>From the manual:
"...T-53B is a biilar winding wound with the master-oscillator 
coil from the ground the the cathode tap  in order that variations 
of cathode-to-heater capacitance within the tube will not affect
the frequency of oscillation.  It is essentially an RF choke."
73 Dave S. AB5S