Aloha Rich and others who have responded, hope
I have the following correct:
In response to my question,
> >Question: leave things just as they are now, or increase
> >the drive power to bring the SSB peak readings back up
> >near 1500 watts?
Rich wrote:
> tune for max out with max drive, provided that the anode
> current rating is observed.
Ok, hmmmm.....
Yes, in my Henry Amplifier manual, Henry publishes a full page
of your instructions on the importance of correct amplifier
tuning. They indicate that the info is reprinted from the March
1989 QST, an article by you, AG6K. But no specific details!
Now, Ok, here is the tricky part.
1. My amp has an Eimac 3CX3000A7
tube. The supply voltage, key up, is about 6200! Unit is
a Henry 8K. So per your method, I would set this puppy up
for the about 5+kW output on CW into the Bird Coax Resistor,
8890-300 dummy load load, for starters.
Presume I would use the 50 wpm dits for this tune up. Would
keep tweaking until the maximum output cababilities
of the amplifier seem to have been reached. Wow,
have no idea how high that might be!
Next step written by others:
2. Then adjust the loading control such that the output
decreases by about 50-75 watts. Said to lower IMD.
3. Reduce the drive to the amplifier to obtain maximum
legal output as seen on your dummy load/peak reading digital
meter.
Depending upon the band, this would cut the input drive to the
amp from about 200 to 275 watts down to about 60 or so,
approximately to come down from the 5000+ output to the Bird.
I have NEVER had the amp put out such power(5000+W) to the
dummy load or anywhere else. I might be afraid to, hi. These
200+ watt drive powers are from Paul Johnson at Henry in
the data sheets that came with my amplifier a few years ago.
4. Assuming that your antenna system is 50R +j0, switch
to the antenna system.
With the tuner between the amp output and the antenna feed, this
is possible.
5. You should see very little change in power output as
viewed on the peak reading watt meter whether you operate
in cw or ssb mode.
6. You can adjust the power output control of the exciter
slightly to achieve the maximum legal power output of the
amplifier as seen on the in-line peak reading watt meter.
Ok, have I got it correct? Bought the 8K a few years ago in
order to have very clean, cool, lowest possible distortion and
the legal output power.
73, Jim KH7M
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