Don't forget that Tuesday will be the first activity night for 222 MHz.
Well, not really the first, but at least an attempt to build some local
activity all over the country. I will be on looking for contacts and
using the ON4KST page along with HB9Q if there is activity there as
well. I encourage everyone who has 222 MHz to make an appearance and we
will see what happens. Conditions here in the NE are pretty punky now
with no tropo condx in sight anywhere, but the SE always seems to have
some tropo. This Tuesday, it will be slightly good in the gulf area. As
the warmer wx approaches, we can expect better results on 222, so lets
try every Tuesday evening.
I went up to the shack today to look into my Channel 11 TV overload
situation. When an antenna is aimed at 219 degrees, CH 11 is in the
pattern and overloaded something. I suspected the preamp. I had it all
working fine last fall, but the front end got wiped out by a winter snow
storm with static, and I swapped out the preamp with a replacement. Now
I had the noise and I suspected the preamp, so I changed the preamp and
put the old one back in after I repaired it. It is an HP AT10135
GaAsFET. The snow static had blown the FET gate along with one of the
source bypass capacitors! After re building the front end, I put it back
in line, and that noise seems to be gone. I see noise variations now as
I rotate the beam, but the variation is slight. It was 3 S units
before! It looks like the overload is gone and ,my LVA antenna now
seems to hear OK with stations at 218 degrees or so. The K1IIG beacon is
on that heading, so it is a good test.
While I was doing these tests, my receive just died. It turns out the
transverter had gone in to transmit all by itself. I unplugged the
keying line and it remained in a transmit state. I brought it down to
my house and opened it up. I measured 1.5 ohms to gnd on the PTT input.
Poking around there made the problem go away. Now I see 13 volts there
when un keyed. I suspected a bypass cap had gone bad, but it seems fine.
Heating and cooling it has no effect. I suspect I had some "schmutz"
causing the problem....most likely steel wool strand or ? Anyway, I will
put everything back together so I will be ready for Tuesday evening.
Remember APRIL 20 on 222.1 MHz CW, SSB, MSK144, FSK441, JT65B, FT8. I
will draw the line with modulated oscillators and spark rigs.
Dave K1WHS
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