[Amps] 2 more questions-- electrical

Gary Schafer garyschafer at comcast.net
Tue Apr 5 09:03:52 PDT 2011


Of course you can have RF in the shack from direct radiation off the
antenna. Your house wiring can pick it up and get it over to your mike as
well as having an unbalanced antenna system.

73
Gary  K4FMX

> -----Original Message-----
> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com]
> On Behalf Of Sam Carpenter
> Sent: Tuesday, April 05, 2011 11:51 AM
> To: dezrat1242 at yahoo.com; amps at contesting.com
> Subject: Re: [Amps] 2 more questions-- electrical
> 
> I have always (almost?) run either balanced antennas with Baluns
> (yagis-dipoles). My problems happened on 75 mostly with phased sloper
> arrays, corner fed delta loops, and flat top 75m dipoles at 80' directly
> overhead. 3 ground rods in good soil and common point shack ground and
> braded ground wire fixed it. I cannot be certain that a lot of it was
> not on
> braids of feedline coming in, but it should not have been on center fed
> resonant dipoles with baluns, nor should the delta loop. It can be
> argued
> that a sloper could use the vertical support (tower) as the primary
> radiator
> and the sloper as the counterpoise. That could render the ground radials
> below the tower useless. These were not balun fed. I had always assumed
> that
> I was in the path of a good level of radiation and not that I had
> feedline
> radiating. I have learned something. Thanks, Sam
> 
> -----Original Message-----
> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com]
> On
> Behalf Of Bill, W6WRT
> Sent: Tuesday, April 05, 2011 10:59 AM
> To: amps at contesting.com
> Subject: Re: [Amps] 2 more questions-- electrical
> 
> ORIGINAL MESSAGE:
> 
> On Tue, 5 Apr 2011 10:31:21 -0400, "Sam Carpenter"
> <sam at owenscommunication.com> wrote:
> 
> >I also notice that he asked about "Shack" ground. Anyone who has run
> QRO
> and
> >used only electrical grounds gets RF burns to the lips on a mic, to the
> >underside of the forearm on the corners of chairs and desks. Sometimes
> quite
> >embarrassing on a voice peak to burn the hell out of your self and
> create
> >another unwanted voice peak. The electric panel is not a suitable shack
> >"RF"ground and things get uglier the higher in power you go.
> 
> REPLY:
> 
> If you are getting RF in the shack, you do not have a grounding problem,
> you have an antenna problem. You do NOT need an RF ground at your shack
> in any way. The only grounds your shack needs are for safety of the AC
> mains and for lightning.
> 
> RF in the shack problems indicate an unbalance in the antenna and/or
> feedline system and can almost always be cured by proper application of
> a balun or unun.
> 
> RF energy is expensive to generate. Do not waste it by running it
> through dirt. Get it up in the air where it belongs.
> 
> 73, Bill W6WRT
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