Re: [TenTec] RFI and Orion Mic connector - bad info

["Richard Detweiler" <rdetweil@hotmail.com>]

If you are having RF problems there may be many causes,  Close antenna, 
grounding, Bleeding, common mode, etc.

Grounding is not the end all answer to RFI problems,  ( although a good 
source of it ).  Too much grounding can cause problems.  Using the wrong 
grounding wire like untinned braid, could cause problems.  But look at other 
problems besides grounding.  The truth is, you may not have a RF Ground 
problem at all.

Taking a step by step approach will solve the problem,  The problem is what 
steps,  This takes some research

ARRL has a lot of info on their web site about grounding,  RFI and all this, 
 you may want to spend some time there to bone up on the subject.

Try to identify if a cable is the problem,  If you have one of those MFJ RFI 
meters ( abt $100) then you can wrap it around a cable to see how much RF 
current is on it.  Otherwise, remove them one by one to see if the problem 
goes away  (obviously the power cable makes the problem go away but it also 
stops transmitting :)

If something is found this way try to analyze why, then what can be done to 
fix it.

The Orion is pretty well RF neutrallized,  So Grounding isn't so much a 
problem,

Look at many peoples examples of solving problems,

In my case when I first set up my station,  and I pressed the key,  My pc 
would re-boot, my screen would go fuzzy, just all sorts of crap,  In 
checking around, I didn't have a grounding probem,  I had bleed problem, had 
to change out all my RG8/213 cabling which was new, to double shielded 
LMR-400 hardline,  That pretty much kicked the RFI problems in the butt, All 
my Station interference went away, including my PC noise.   Apparantely the 
lower velocity and lack of full shield of RG8 allowed too much RF out of the 
cable,  and into the shack.  Thus it wasn't a grounding problem

I did make changes after the fact to the ground,  I live on the second 
floor, so I've got a long ground wire,  I went in and used sheilded coax 
cable ( from the original RG8 which was New ) for the ground wire to 
reduce/prevent the ground from picking up or radiating RF,  Connected the 
shield and center conducter to the ground rod,  then connected only the 
center conductor to my ground at the station.  The ground rod is really a 
gounding system, it is many ground rods connected by wires all within a few 
feet.  With the Shielded Ground wire,  rf is less likely to pick up or 
radiate from ground system,  It's not perfect perfect ground, but it did 
help some.

There are other things to work on, but for now, all is quiet in the shack 
when I press the key.

73's
Rich
K5SF


> From: Kc9cdt@aol.com
> Reply-To: tentec@contesting.com
> To: tentec@contesting.com
> Subject: Re: [TenTec] RFI and Orion Mic connector - bad info
> Date: Thu, 22 Apr 2004 09:38:09 EDT
>
> I run 80-10 meters (like most folks) for my location of the ham shack
> (basement) there is no way to have a ground less than about 16 feet.
>
> So what to do?
>
> 73,
> Lee, KC9CDT
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec

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