[Milsurplus] TBW Key Clicks/ Chirps

[Richard Brunner]

About the series capacitor...
The power circuit can be modeled as a perfect generator in series with 
(generator)reactance, capacitance, plus the transmitter load, which is 
mostly resistive.  The capacitive and reactive voltages are in 
quadrature with the load, so big voltages can appear across the 
capacitor.  In the TBW the line voltmeter is connected at the input to 
the transmitter, effectively between the reactance and the capacitor, 
and when not optimally adjusted, key-down there are large voltage 
excursions as it reads the load plus jX voltage. When the capacitor is 
properly adjusted there is hardly any voltage change on the meter as the 
capacitive and inductive reactances nearly cancel, though there are 
about 100 volts measured directly across the capacitor.

Richard Brunner, AA1P