One other solution.......... use a balanced feed system. If it is balanced,
no RF ground needed.
My shack is on the 2nd floor of a wood frame house. The antenna which does
not run over the house is 75 feet away fed with balanced feed line. Other
than 3rd pin safety ground, there is no ground on the radio equipment. I
often run legal limit 160M - 10M any mode with no RFI issues. No computer
noise either. Primary power is supplied to the station via #8 / 4 direct
from the beaker box to the operating position. The reason for 4 conductors
is L1, L2, Neutral & Ground. That run is about 75 ft. There it is a
disconnect in the shack which allows me to have 6 duplex outlets, 3 on each
side of the 230V line to neutral, plus a 30A 230V for the amp.
73
Bob, K4TAX
----- Original Message -----
From: "Rob Atkinson K5UJ" <k5uj@hotmail.com>
To: <tentec@contesting.com>
Cc: <k5uj@hotmail.com>
Sent: Thursday, April 22, 2004 10:18 AM
Subject: [TenTec] RFI and Orion Mic connector - bad info
> I used to have my basement shack at the end of a 20 foot ground cable. I
> was getting back into the game after being off HF for many years and I
> (obviously) had forgotten a lot about station building if I ever knew
> anything to begin with. I moved the whole shack and cut the ground run
down
> to about 5 feet. Are you really sure you can't get closer to your ground
> rods? If not, I can only think of 3 options: 1. Tuned ground
> "counterpoises" one for each band or a matching network for one wire (MFJ
> "artificial ground"). These are wires cut so that on whatever band you
want
> to use, one of them will be at a low impedence at your rig's ground lug.
2.
> Not having any ground at all. Some hams claim this works for them but I'm
> not convinced it's a good idea. 3. Drilling a hole or holes in your
> basement floor at your rig and sinking a rod or rods through the concrete.
>
> Invest in a bag of 20 or 30 split bead ferrite chokes and put them on
> equipment leads. (the brute force approach) Expensive but you will be
> amazed at how quickly you wind up using them. If a lead has a shield and
> the shield is only for that and is grounded at both ends try grounding it
at
> only one end (the nonOrion end).
>
> Take a look at this approach to deal with RF coming back in on the shield
of
> coax feedline:
> http://www.radioworks.com/nliinfo.html and coax ground loops.
> While this ham is naturally trying to sell his line isolators, the
> information contained here
> is still useful and worked for me as a solution.
> I had awful RF problems with a Omni VI running 1 kw because my antenna is
> only 20 or 30 feet from my shack. I shortened the ground run, used
ferrite
> chokes on equipment leads, employed line isolators and the radioworks
ground
> configuration and these techniques fixed my problems.
> since this could be overkill for you, try what Bob said about testing one
> lead at a time.
>
> Rob Atkinson
> K5UJ
>
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