[ARC5] Power supply for chirp-free op. ?

[Mike Morrow]

Doug wrote:

>If you folks know of a way of getting chirp-free operation without the relay
>as well as a way to use the unit without a tuner into a 50 ohm load that
>info would be helpful as well.

Doug,

This relay has nothing to do with chirp when the transmitter is used *as intended* by the set designers.  This relay and the antenna connect relay are transmitter select relays that are energized continuously as long as the transmitter is selected for use on the control box (i.e., transmitter in rack position one is selected when the control box's selector switch is at the number one position).  They do not cycle as the mic PTT or Morse key is cycled.  The original design keys the HV supplies to the transmitter with a HV keying relay in the modulator unit.

Keying a command transmitter with the relays in the transmitter is a ham innovation which is outside the intended function of the original design.  You could make your unit function in the original manner by wiring the circuits (PA cathodes and oscillator HV) as if the (missing) relay were energized, then key the HV inputs to the transmitter with an external relay.

I find it very interesting when this historic equipment is operated today as near as possible to the same manner as it was in original service.

Mike / KK5F