Absolutely you should ground your tower to your shack, as well as to your AC
ground with no less than a #4 conductor, which I believe is an NEC
requirement. The problem arises when there is a lightning strike, in which
case you want every single conductor in your home to have exactly the same
voltage so there is no potential difference that could kill you or your
equipment. Of course, with 20 megavolts, the tiniest of resistance will
cause a fairly big potential difference, but you want to do everything you
can to keep it as low as possible. That's why it's best to establish an
"entrance window" where everything is 'star' grounded to a master ground
point.
Of course, that's not an RF ground, but it may help in many cases,
especially on the lower frequencies. You can break up ground loops by using
ferrites, and a good place to start on this one might be in the cable from
the power supply to the radio and/or the power supply to the AC.
Ron N6IE
www.N6IE.com
(Formerly N6AHA)
----- Original Message -----
From: "Larry Menzel" <retire@means.net>
To: "'Discussion of Ten-Tec Equipment'" <tentec@contesting.com>
Sent: Friday, January 26, 2007 8:26 AM
Subject: Re: [TenTec] Orion RF issue
>I agree with others on this, it seems that the only time I suffered from
> this was with very high swr, significant voltage drop, or the wrong
> antenna.
>
> The Orion must have a solid 25 amp supply, so if it's only say an Astron
> RM25 you need to make sure that the radio is the only thing on that
> supply.
> An RS or RM 35 is a better bet, yet.
>
> I guess that would be my recommendation, as well, but I'm curious about
> your
> tying your shack ground to the tower ground; I remember well, many
> sources
> stating that under no circumstances should the two be connected.
>
> Anyone else have an opinion on this?
>
> It would seem foolhardy to me to do so, as a strike on the tower would be
> instantly transmitted to the station grounds and could cause significant
> damage...assuming of course that all other precautions had been taken,
> unplugging equipment, etc., but I never unhook my ground system on my
> shack.
>
> Curious.
>
> Larry, N0XB
>
>
> -----Original Message-----
> From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com]
> On Behalf Of Natan Huffman
> Sent: Friday, January 26, 2007 10:16 AM
> To: tentec@contesting.com
> Subject: [TenTec] Orion RF issue
>
> Ladies and Gentlemen,
>
>
>
> Today I took delivery of an Orion with version 2.056 firmware and
> integrated, with great ease, the rig into the station. Unfortunately I am
> having an issue while on 80 meters where my antenna is near the shack and
> only up 50 feet. The station is grounded well as is the house with each
> having two 15' ground rods and short ground wires < ¼ lamda at 80) .
> These
> grounds are tied into 4 more at the base of the tower about 50' away from
> the shack. I doubt the problem (white screen when transmitting) is due to
> lack of grounding but rather the presence of a strong RF field generated
> by
> the 80 antenna. Just for fun (done in 4 degree wx) I disconnected the
> large
> bus to the tower base and no change. I also checked VDC at the plug in
> the
> back providing power and it's fine.
>
>
>
> This problem is not seen on two other transceivers in the shack when used
> on
> 80, which also suggests the problem is RF from the antenna. Might there
> be
> some remedy so that I don't have a white screen when transmitting?
>
>
>
> Thanks in advance,
>
>
>
> Natan W6XR
>
>
>
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