[Collins] Transformers

[Dr. Gerald N. Johnson]

The right value series capacitor drops voltage, the wrong value 
resonates the inductive load and raises the voltage. I have used a 
series capacitor to slow and quiet an AC fan. But I believe I could run 
a 220 volt fan on 120 with the right capacitor to come close to 
resonating the higher voltage winding. And have 220 volts RMS on the 
motor winding.

A receiver load is a bit volatile too, especially one with a standby 
switch and/or class AB or B audio. Generally in a communications 
receiver the RF gain changes the plate current of every gain stage but 
audio and oscillators, as does AGC.

73, Jerry, K0CQ

On 8/29/2013 5:49 PM, james.liles at comcast.net wrote:
> Hi Gerry:
> Might consider a polypropylene film capacitor in series with the
> primary. Provides about the same effect as a series resistor without the
> heat loss. Works well in receivers that use gas voltage regulation for
> the oscillators. Use 30uf per 100 watts for a 6 volt reduction in line
> voltage. Reduces in rush, has about the same line voltage regulation as
> the bucking transformer but regulation is sensitive to load like the
> series resistor. Can't be used in a transmitter where the load is
> volatile. There, the bucking transformer or autotransformer are the answer.
>
> Kindest regards Jim K9AXN
>
>