Hi,
In an attempt to get back on RTTY, I've been able (thanks to the
many fine people on this reflector) to interface by TNC to my
rig, a JST-245.
By necessity my shack is on the second floor and I am currently
using a long wire antenna (175 feet) and an old (AEA-3000) tuner.
Everything loads up fine and I am able to work SSB without any
difficulty. RTTY is another matter. Every time I key up, the
station locks up... the computer freezes, the TNC has to be
turned off, reset, and reinitialized.
I attributed this to an excessive amount of RF and toward that
end I built a small RF sniffer using a 50uA meter and a few
parts. Needless to say I have a real RFI problem. Even at low
power of about 5 watts, the sniffer meter pegs. I've got about
20 feet of RG-8 that I use for a 'feed-line' and the radiation off
the shield is fantastic.
I attempted to remove the RG-8 and hook long wire directly to the
tuner. That reduced my radiation by about 20%, but did not solve
my problems. I installed a 'counterpoise' ground system and loading
is sharper, but the problem remains.
Oddly, in SSB operation, the radiation is inconsequential. Only when
I run RTTY does the duty cycle cause a radiation problem. Also, I've
noticed the radiation builds quickly after 5 seconds of operation
from little, if any, to excessive.
CW causes no troubles.
My thought is that I need to 'move' the RF away from the rig and
hopefully into the antenna.
Any assistance in this matter would be appreicated.
Thanks,
de Phil - N8PS
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