On Tue, 15 Mar 2005 12:53:33 -0500, clvrmnky
wrote:
I've had an epiphany of sorts, and I think you may be partially to
blame! Well, that and "Basic Electronics" published by the US Navy.
Hi OM,
I was an Instructor at the Navy's Electronic Technician School at
Treasure Island. Get yourself a copy of Terman's "Electronic and
Radio Engineering" (the 1955 version) to find the level of coursework
that was offered at this school. It is very accessible reading and
noteworthy for being comprehensive without being a sleeping pill.
However, last night I realized that I can think about a RX antenna as an
HF AC current /generator/ running with a small voltage potential (i.e.,
~1 uV), and that my receiver completes this AC circuit.
Good that you picked this up yourself. It is a useful metaphor.
Then it follows that a longwire needs an RF ground (of some nature) to
"complete" the circuit. Hence, the use of a counterpoise in some
situations. My receiver is one part of an AC circuit that wants some
kind of RF ground to see the voltage potential being generated by the
antenna. Crystal radio sets seem less like magic now.
Quite so.
It follows that all the ground I should need (for good
operation) is a good chassis ground, even if that is only the neutral
side of the wall-wart (is that where it is?).
Well, this is getting close to the mystery of your understanding. As
simple as ground is, it is so often taken for granted that many don't
really understand it at all.
As for the Neutral connection of the mains NO THAT IS NOT GROUND!
DO NOT PROCEED FURTHER with any wire work at that service until you
research this completely.
However, as a point of intuition, ground is so tightly coupled to this
wire (at RF) so as to be the missing half of the longwire system.
This is why I commented on the distinction of being completely battery
operated (hence no ground coupling).
Other issues like ground
loops, reduction of common-mode noise &etc. is a separate issue; these
can *sometimes* be solved by different devices on the antenna system,
but I see now how they could also add problems.
This goes again to the common misunderstanding. You won't suffer a
ground loop until it occurs. Solving it will be one of life's
greatest struggles, and the solution, if stumbled upon, will appear to
be one of life's greatest mysteries. Again, battery operation creates
its own bubble of isolation from these issues - however, adding a
charger brings the prospects back into the equation.
So, when people complain about balance/unbalanced situations, ...
Here you get into uncharted waters. Spend some more time here before
you solo again.
73's
Richard Clark, KB7QHC
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