Update on my Centaur's inability to properly function on 15 meters.
After testing and checking all the circuits of the amp and after
numerous conversations with Paul at Ten-Tec the problem still exists.
The amp is properly tuned up but initial output on 15 meters is 150/200
watts at 65 ma grid current and 750 ma plate current. If you "key down"
for abt 5 seconds the grid and plate current starts to rise and output
goes up accordingly. After several five second "key downs" in very
rapid succession it "is" possible to achieve 500 watts output with a
grid current of about 100 and plate of about 750. However, if you let
the amp sit to cool for 30 sec or so (and it gets HOT) then it reverts
to output levels of 150/200 watts until you do the drill all over
again. To maintain the 500 watts you must fiddle with tune and load and
not let things cool off.
Paul checked with the engineers at TT and we have decided that the
problem may not be with the feedline or amp (it worked fine for them
when I sent it to them last week) but rather with my Omni V. At 100
watts I have never noticed a problem but the engineers think that
something in the Omni is transmitting spurious frequency signals along
with the proper carrier...... and the amp can only amplify one frequency
at a time. As the bad component in the Omni V heats up when key down
into the amp the spurious elements of the output abate and the amp
starts to work properly.
I sent the Omni to TT today so I should hear back pretty soon. I hope
the problem is found in the Omni so I can solve this interesting
phenom. I'll post to the list when the solution is found. This is,
while frustrating, very interesting and I know the internal operations
and sections of my amp and Omni better then I ever expected to <grin>.
Thanks .... everyone for all the helpful suggestions !!
73 de Mike
--
Michael Melland, W9WIS
Winneconne, Wisconsin, USA
FISTS #4387, 10-10 #69281, QRP-L #1656,
QRP-ARCI #9875, AK/QRP #478, NorCal
CW, SSB, and Electronics
List Administrator: grundig@qth.net
http://www.qsl.net/w9wis
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