[RFI] RFI/EMI MAJOR Problems
Rob Atkinson, K5UJ
k5uj at hotmail.com
Thu Nov 30 13:37:28 EST 2006
one other thing--ur conductors to all ur rods are too long and too small.
Get rid of anything stranded and or braided. Use flat copper strap, at
least 1 inch diameter but 2 or 3 inches is much much better. I'd try
running the vertical without any line to a ground rod after you install
enough radials. The shack ground run should be no more than 8 feet long.
If there is no way to have a shack ground run that short (for example the
minumum has to be 20 feet) then I'd think about operating without a shack
ground. There's usually a way to do it however, such as moving your station
to be near your service panel so everything, feedlines, cable tv etc. can
enter through a grounded plate that's bonded to rods outside that are also
used for telephone and AC service ground. Wherever your shack ground comes
in, strap all your gear directly to it with discreet lines, one for each
piece of active equipment (feedline tuner included), and don't use any thin
lines--use at least 1" copper strap.
rob / k5uj
From: "Bob Gates" <regates at hughes.net>
To: <rfi at contesting.com>
Subject: [RFI] RFI/EMI MAJOR Problems
Date: Wed, 29 Nov 2006 20:17:20 -0800
I wish all I had to deal with were little noises in my receiver. All of my
little noises are in my head. I apologize if the problems I'm about to
describe are not best suited to this forum, but I can't find one that seems
better suited. If there is, you certainly won't hurt my feelings if you
tell me to look elsewhere.
My problems start when I turn on the linear, at anything over about 500w
output. At that point I generate major TVI, to the tune of completely
blanking out the screen. All cordless phones receive my signal S9, before
disconnecting the phone altogether. I start tripping GFCIs in some parts of
the house, and can even lock up my PC on one band, after listening to
audio/cw coming through the PC speakers. I have mix 43 toroids, in various
combinations, all through the house, to the tune of 48 of them.
I have 8 of them forming a common mode choke at three points on my single
antenna feed line. I have another choke on the power line for my UPS, which
has my PC hooked through it. I've got the AC power lines for all the TVs
and base unit for the phones wrapped w/ 12 turns around a toroid. And I
have an 8 toroid choke on the amplifier's power line.
Since adding all these chokes, I've gone band by band to see if one is worse
than the other. Haven't checked 10M since I don't use it. On 15M, my PC
locks up and sound comes through the PC speakers. TVI is not too bad, and
minor interference on the phones. No GFCIs seem to trip. 20M is the only
band with no problems of any kind. 40 and 80M are the most serious. Almost
ALL of the problems I described in the second paragraph. Major TVI, cuts
out the cordless phones, trips GFCIs. But no problem with the PC.
Antenna is Butternut HF6V on the roof of our two story house, and the shack
is on the lower level. Antenna ground is about 60' of 2x14 romex. Don't
know what the solid wire equivalent of 3 #14 wires is offhand. But it
terminates on the opposite side of the house from the station ground,
clamped to an 8' ground rod driven in 7-1/2'. My station ground system has
all major components connected to #2 stranded copper wire, about 30' total
length, which terminates clamped to a 1/2"x8' electrical ground rod, driven
in to within about 4" of the surface. Nothing else is connected to either
the antenna or station ground. There is a ground wire for the house
electrical panel that seems to be #2 stranded copper, but I can't tell where
it's terminated underground since the ground here is a tad bit frozen right
now. Everything in the shack connected to AC is on a separate circuit run
directly to the panel, as is the 220V amp. Rig is a FT1000MP Mk 5 and the
linear is an Emtron DX-3.
Hope I haven't overwhelmed you with useless information. I would certainly
appreciate any advice on the source of this mess, and potential cures.
Thanks in advance.
73, Bob W7BJ
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