[From nobody Mon Jan 10 18:47:51 2011
From: "k5cr@juno.com" <k5cr@juno.com>
To: "john.clark@STATE.CO.US" <john.clark@STATE.CO.US>
Subject: Re: FW: HW-101 step 4
Date: Tue, 11 May 1999 09:30:06 -0600
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John:

I see you have received a couple of replies on your oscillator question.


I will give you a little theory.

As you peak the oscillator (using a VTVM to monitor the grid voltage)
you
will get a higher negative voltage the as the plate tank circuit is
tuned
to resonance.   (Oscillator run in Class C so there is grid current that
inturn drives the grid more negative).  On one side of resonance you
will
find the grid voltage has a nice gradual peak, while the other side of
resonance the tuning is sharper and falls off rapidly.    The higher
grid
voltage relates to a higher RF output voltage from the plate circuit.

The goal here is to get the highest output from the oscillator.
However,
you don't want to peak the plate tank circuit and leave it tuned to the
peak.   You want to peak the tank circuit but back off (on the slow
peaking side of resonance) to about 80 to 90 percent of the peak grid
voltage.    The reason for not leaving the oscillator tuned to the peak
is you want the oscillator to start oscillating each time it is turned
on.  If you peak the adjustment there is a good chance with aging the
oscillator won't start or it will quit oscillating when loaded.

I hope this helps answer your question.

73

Doug/K5CR


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