[Lowfer] WC2XSR/13 - The Sage Continues!

[Ralph Hartwell]

Sigh...  If it weren't for bad luck...   Naw, just kidding!!  I guess
it's just the nature of working in a new area that the bugs have to be
worked out of things.  Or, in this case, burned out.

A couple of days ago, if you recall, the "T" insulator on the upper
loading coil burned up. Well, last evening, I shut the transmitter down
and replaced the loading coil support pipe portion of the insulator.
The connections were still "hanging in the air", but it was working.
Hmm.. air insulation,  I like that.  I can't burn THAT up!

Anyway, I had planned that today I would replace some of the feed wire
and connections between the bottom of the vertical antenna wire and the
output of the antenna tuner. I wanted to do this because when the wind
blows fairly briskly, the feed wire moves enough in the breeze to detune
the antenna.

So, I went outside this morning and started to measure for the
modifications, and when I looked up, I saw that the first PVC pipe
support for the feed wire had burned back about 14 inches towards the
tower.  Here we go again!!  Off to Home Depot for more antenna parts.

An hour later, I was back home with a couple of 10 foot lengths of 1/2
inch copper pipe, a bunch of copper elbows, and, of course, some more
PVC pipe!  Several hours of sawing, soldering and sweating later, I had
replaced the feed wire with pipe, and supported it with two new (I guess
I never learn!) PVC insulators, both of which now sport nifty #12 wire
corona rings.  We'll see how those hold up.

I had to retune the antenna due to the modifications.  I found that I
had to go one tap further up on the variometer coil switch, reducing the
inductance needed to tune the antenna. That means that the antenna has
more self-capacitance than it did with the wire instead of the copper
pipe.  That is what I expected, since the pipe passes closer to the
tuner cabinet and is a bit longer than the wire was.  It is also larger
in diameter, and will exhibit a greater capacitance-per-foot than the
wire it replaced.

Unfortunately, this higher self-capacitance will also reduce the
effective height of the antenna somewhat, resulting in a weaker signal.
OTOH, the transmitter loads a bit heavier, meaning that the loss
resistance in the antenna system is a bit less (fewer turns of wire on
the loading coil) so these effects may just about balance out.

I have placed the station log of WC2XSR/13 on line at my SHMRG web site.
I'll upload log changes as I make them, so you can see what's happening
pretty much as soon as I make changes or add to the station log.  The
log is the top link on my personal SHMRG file list link section.

73,

Ralph   W5JGV / WC2XSR / 13

http://home.att.net/~shmrg

http://home.att.net/~ralph.hartwell