[Lowfer] Isolation Transformers

[Les Rayburn]

At 04:06 PM 8/19/2002 -0500, you wrote:
>John Andrews' technique of isolation at both ends of the cable sounds like
>the best way to go. If there is noise pickup anywhere along the cable, some
>fraction of it can make its way to either end. But if I had only one set of
>isolation components, my preference would be to put them at the shack end,
>and ground the cables only at the preamp end. This assumes that the noise
>level is higher at the shack, which is usually true unless you've picked a
>really poor location for the remote antenna :-)
>
>Lyle, K0LR


With respect to all, this seems to be a case of "more than one
way to skin a cat". However, this humble student wants only
to complete this installation with a minimum of "trail and error".

As I mentioned, I'll be using quad-shielded cable for the feedlines,
all run in a 16" deep trench back to the shack. I've got isolation
transformers ordered from Mini-Circuits and also snagged some
chokes today for the DC feeds if needed.

I'll be powering both the pre-amps and tuning circuits
from batteries in the shack, and the receiver is
also powered from another battery supply.

So, two questions:

1. Best to install a virgin ground at the base of the active
whip and also the loop? (They're about 60 feet apart)

Or better to just isolate the transformer and have no ground
on that end?

2. Should I use the DC chokes on the +12 V running to the
pre-amp and also the 1-9V tuning signal or not? If so, should
they be installed near the antenna or near the battery in the
shack?

Thanks again...this list is a godsend to me. The advice is always
appreciated!

73,

Les Rayburn, N1LF