Richard Clark wrote:
On Thu, 15 Mar 2007 21:12:03 GMT, Irv Finkleman
wrote:
Is a copper to copper contact always necessary in
an antenna or does solder provide the necessary
continuity when joining wire?
Hi Irv,
In the Navy, I taught (per the syllabus) that you made a gas-tight
electrical connection between conductors and sealed it with solder.
Solder was not expected to maintain the electrical or mechanical
connection. An example would be a Western Union Splice, then flowed
with solder.
Yep! The good old 'Western Union Splice' one of the first things
I learned way back when.
I am disregarding the special case of magnetic
loops where RsubA must be kept low. I am also
disregarding the matter of mechanical integrity.
That pretty much conforms to what I say above. However, having said
that, Lead, Tin and other alloys are usually good conductors when used
in suitable quantity (or with sufficient surface area). There is
nothing wrong with a soldered joint in a magnetic loop, although a
soldered loop can easily be done poorly.
I must have had a Senior's moment. I was thinking of a mechanical
joint rather than a soldered one. In a magloop, which is one of the
projects I'm working on now, I plan to use copper and silver-solder for
sure.
There are other issues of weathering of solder, and galvanic
reactions. This argues sealing the solder with rubber or synthetic
coating, and/or examining the metals involved. This is usually a rare
issue to be concerned about.
As per Owen's post I will consider a sealant or protection of some
sort. In any event, the major effort is installing radials which
will be soldered to a ring of copper wire around the base of the
antenna -- it will be readily accessible for inspection and
repair if required. I don't want to have to to that too often
though -- and I sure as heck don't want to run out and dig through
the snow when it's 30 below! :-)
In my case I am looking at soldering radials to
a piece of copper wire at the base of an antenna, and
also adding a bit of length to the radiating
element.
What about the use of wire nuts to join wires?
They enforce the gas-tight connection and preserve the seal of that
interface through spring force, but usually in a dry environment (I
suppose you can find weather proof versions).
Wire nuts with suitable protective coating after connection
may just be the easiest way to go. I only want to put out
8 radials. As for the radiating element, it doesn't have a lot
of strain on it either, but I think for temporary testing I'll just
use a quick twist of the wire and solder it until I find the
length I want -- then I'll do a Western Union bit with just a
few turns, then solder flood it. It is #12 and shouldn't
be a problem to twist in a fancy manner.
Thanks for the ideas.
Irv
The antenna is an HF marconi in an inverted-L configuration.
Thanks for any advice on the matter.
Irv VE6BP
73's
Richard Clark, KB7QHC
--
--------------------------------------
Visit my HomePage at
http://members.shaw.ca/finkirv/index.html
Visit my Baby Sofia website at
http://members.shaw.ca/finkirv4/index.htm
Visit my OLDTIMERS website at
http://members.shaw.ca/finkirv5/index.htm
--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada