Hi all:
I have used my Ten Tec 420 in the mobile for several years with very little
trouble.
I did fry two of the final transistors once due to a short in the antenna.
I needed
to get back on the air fast. I didn't have the motorola transistors that
Ten Tec uses
and was unable to find any at a reasonable price. I had several 2SC2879
transistors
which are spares for a KW homebrew amplifier I built. I replaced all the
transistors
in the Ten Tec with these. After readjusting the bias to the correct idling
current I
was back in business. No other changes were needed. The gain was higher
so I
had to keep the drive level down in order not to exceed the 600 watt output
levels.
I found out this is necessary the hard way when I was pumping along at about
800 watts and lost a capacitor in the 20 meter bandpass filter.
At about $16 each the 2SC2879 is an idea transistor and I'm sold on it. My
homebrew amp uses 8 200 watt modules for a total of 16 transistors. This
has been running for about 4 years without a single failure.
73 Don KH6DX/mobile
kh6dx@arrl.net
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