Heat is indeed the enemy of RTTY. Air, air, and a lot more Air. I
recall the Portland, Oregon National ARRL convention a long while back.
Right next to Bill Henry and the Hal Communications booth was the famous
brick on the key amplifier company. They had this new amp that was
advertised at 100% duty cycle. I got to talking to the guy and told him
I would but it and then run it in an upcoming RTTY contest (which is
about 30% keydown BTW) after a couple of 30 minute RTTY ragchews (which
we used to have on the bands commonly).
He said, whoa...well we have this special option for this extra fan for
RTTY. Needless to say when my old buddy Ron K5DJ then AB5KD bought that
new shiny Alpha it came with the extra RTTY fan option.
And its not only the power supply but also the tank circuit in nearly
all amps that gets killed with RTTY. Even an old Henry has that
problem. Plenty of PS but I have melted the solder out of the tank on
several occassions. Until mounting fans above the tank and in many that
is very difficult. Note AL-1200 which used to have a rather small set
of holes over the tube exhaust was in later models increased greatly in
size. In their AL-1500's which we ran at the W5KFT ranch we always had
one or two muffin fans extra blowing air usually one in and one out.
As Joe sez more air means fine teletype that's MAMFT a new one for ya.
Jay WS7I
On 9/24/2012 12:49 PM, Joe Subich, W4TV wrote:
Even at 400 W, I would look for ways to add auxiliary cooling.
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