Date: Wed, 13 Apr 2011 15:55:15 -0600
Reply-To: "John C..." <jcarp1910@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: "John C..." <jcarp1910@GMAIL.COM>
Subject: Re: radio whine - success, failure, success
In-Reply-To: <4da60cee.9247e60a.55f3.1d7a@mx.google.com>
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What is that grounded Shield Cylinder
around some of the Distrubutors?
I thought that was for the radio reception.
but that's just a wild guess on my part.
On Wed, Apr 13, 2011 at 2:35 PM, David Beierl <dbeierl@attglobal.net> wrote:
> At 08:07 PM 4/12/2011, Alistair Bell wrote:
>
>> So now I have determine if that kind of grounding through antenna is
>> normal, or a fault.
>>
>
> I don't actually know for certain, but I'd be fairly surprised if the
> shield on the antenna lead weren't connected to the mount. It's
> certainly not *meant* to be a power ground, and it might shield the
> lead as well or better if the mount were isolated - on a transmitting
> antenna this would be a crucial difference but not as much on a short
> receiving whip. One of the VHF hams would probably have a good
> opinion about how badly it's expecting to see a ground plane on FM;
> it's so far out of resonance on AM that in my ignorance I doubt it
> makes any difference. Back when people cared about AM car radios
> used to have trimming capacitors for antenna tuning (and they had a
> strong peak, too) but I haven't seen one since the '70s.
>
>
> You said you moved the supply/ground but didn't make entirely clear
> whether you've got a big fat ground connection directly between the
> two units. I don't think we got to the scribbling stage in that
> conversation, and there are a number of interrelated issues (and I'm
> not an expert by any means). I'm enclosing a diagram showing how one
> boutique manufacturer (Milbert Amps) thinks about grounding. It
> won't show up on the list and I don't see it on their site to point
> people to it but I'll send it to people who ask.
>
> As a practical matter though, I think the isolation transformer (aka
> ground loop isolator) we talked about in the signal grounds should
> take care of you.
> http://www.radioshack.com/product/index.jsp?productId=2062214
>
> :)
> d
>
--
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and the Alps is for children to climb! These here is God's finest
scupturings! And there ain't no laws for the brave ones! And there ain't no
asylums for the crazy ones! And there ain't no churches, except for this
right here! And there ain't no priests excepting the birds. By God, I are a
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I'll leave my bones on this great map of the magnificent...
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