[Milsurplus] LM-18 and AC PS Questions.. More

[brunneraa1p at comcast.net]

From: J Forster <jfor at quik.com>
> That still does not answer the question why are the capacitors switchable, when, 
> if properly set up, there is no need to change them. It it a design error?

The transmitter power supply load is mostly resistive, but must have some reactance which enters the equation.  The capacitors are set by observing filament voltage change key-up and key-down, selecting capacitance for best regulation.  Load reactance might change a bit with different transmitter loading, necessitating different capacitance settings.  That's my best guess.  The capacitance value could also be too critical to be satisfied with a generic factory value.  It could also change if there is other apparatus connected to the 120 volt 800 cycle line.

Richard Brunner, AA1P