[R-390] Positive ground (slightly off topic)

Tue, 3 Sep 2002 09:50:15 -0400

Thanks for your idea Bill. I have been toying with something similar to what
you suggest, insulating the base of the antenna (normally grounded), and
using coupling caps. However, I want to use this as a multi-band set-up, and
using caps may preclude that due to the different values of capacitive
reactance on each band.

My other thought is to use an auxiliary battery, with a DPDT switch. In
"normal" use, the second battery could be across the car's main battery, and
get charged from the vintage car's generator. Then, when I throw the DPDT
switch, I could ground the negative terminal of the secondary battery, and
feed the positive voltage to the rig. I may wind up doing that.

Vy 73, AI2Q, Alex  .-.-.

-----Original Message-----
From: Bill Smith [mailto:[email protected]]
Sent: Monday, September 02, 2002 5:19 PM
To: [email protected]; R-390 (E-mail)
Subject: Re: [R-390] Positive ground (slightly off topic)

How about coupling with large value capacitors (0.005, 0.01 mfd)?   Transmit
Mica caps should do the trick.  You should also "ground" your rig with
similar caps.  I am assuming your rig is insulated from the automobile
chassis due to reverse polarity (positive ground).

73 de Bill, AB6MT
[email protected]

----- Original Message -----
From: "AI2Q Alex" <[email protected]>
To: "R-390 (E-mail)" <[email protected]>
Sent: Monday, September 02, 2002 1:50 PM
Subject: [R-390] Positive ground (slightly off topic)

> Hello all:
>
> Given the pool of technical knowledge on this list, I wonder if anyone can
> suggest a way to feed a typical HF mobile whip antenna (center loaded,
with
> low-Z feedpoint) in an installation where the car's electrical system uses
a
> positive ground.
>
> I tried feeding a Hustler whip through a homemade toroidal coupling
> transformer in order to achieve DC isolation, but my transformer seems
> inadequate to achieve adequate coupling. I'm not interested in reversing
the
> vintage car's system polarity. The transceiver is an Atlas-210X.
>
> Any thoughts?
>
> Vy 73, AI2Q, Alex   .-.-.
>
>
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