It's a new hole -- two days old now though. I am using an MFJ-1623
tuner which also includes tuning for the counterpoise ground which I'll be
using.
The wire will be enough to hold one small bird -- if necessary
I can always rebuild with heavier wire (the MKII version
I mentioned before)!
I checked carefully before I drilled and missed the glass
entirely which is unusual because Murphy lives with me! I've
never seen him, but his influence is always around!
The magnetic loop would not be using the
window frame -- I have some 1/2 inch flexible
copper tubing which I brought from my condo
(which will officially be off my books at noon today!)
Last week we had a flea market in Calgary. Having given
away all my precious ham radio parts (aka junk) I was in dire
need of a roller inductor and a variable capacitor or two
to build (if necessary) an artificial ground, or a matching
device of some sort for whatever purpose I might dream up.
I walked into the market, paid my admission, and the first
thing I saw was a box (about 4 cu ft) of variable caps of
assorted shapes and sizes. I bent down to have a closer
look since I could hardly believe my eyes, and asked the
seller 'How Much?' At the same time, I noticed another
box of the same size full of assorted inductors, some
roller inductors, some coil forms, some coil stock and
such. It was like a dream come true. The seller
responded '20 bucks for the whole box' and I asked
'How about 20 bucks for both boxes' and he
accepted! Talk about a lucky find -- some of that
stuff is hard to find nowadays, and to purchase would
cost a fortune. I have both boxes in the trunk of my
car as there is little room in my suite to allow me to
start collecting parts aka junk! I've brought the cream
of the crop up to my suite and have cleaned them off
using an electric toothbrush and a mildly abrasive
cleaner -- they look like new. I now have sufficient
L and C, both fixed and variable, or every sort and
description to keep me happy for a long while. The
rest I will store in my brother's garage until the next
flea market where I intend to recoup my $20 bucks
plus the admission price!
I've tested the MFJ-1623 and it will work 80 thru
10M with the wire -- the wire is basically the same as
the 12 foot whip only longer but thinner. If it doesn't,
I have another MFJ-949E which I got as junk because
the coil switch was burned (I replaced it in an hour
with a new single pole 12 position) and it's been
tested and used by a friend of mine for the last
couple years. If one or the other works or doesn't,
I've got all that LC stuff from the flea market so
if necessary I can put together enough to load a
wet noodle.
I did load a wet noodle once, and worked from
Penhold AB to Red Deer AB (about 10 miles)
just to show it could be done! I love antennas.
Does anyone recall reading a book on antennas
that had a Chapter subtitle saying 'Antennas are
Funny People!'? I'd love to find the book again.
My carpeting is wall to wall, so the chicken wire
ground would have to be on top of the carpet. I'm
sure though, that if anyone asked, I would simply
explain 'I'm a Ham' and they would shake their
heads understandingly and not ask any more
foolish questions!
One way or the other, with the planned
setup, I intend to get some signals out -- come
hell or high water. I don't give up on my hobby
after all these years, and I've helped many a ham
get on the air under worse (but not much worse)
circumstances.
Gotta get downstairs and vote -- we are having
our provincial election today!
73
Irv VE6BP
"Jeff Liebermann" wrote in message
...
On Sun, 22 Apr 2012 23:18:17 -0600, "Irv Finkleman"
wrote:
I just want something quick and cheap so I've ruled out
anything like copper clad steel and such.
Will your 25ft span of copper wire support a few birds? If not,
please reconsider copperweld.
Just to clear things up on the geometry, the wire will run
out the window horizontally to the tree (about 25 ft) and
then drop vertically (another 25 ft approx) through the
tree to just above the
ground. Sort of an inverted letter "L". It is just a
random wire, and the best I can do at the moment
given my current situation.
Do you have an antenna tuner? The FT-817ND does not have a built in
antenna tuner. You're going to need one with your random wire and
random configuration.
The hole through the window frame is too small (1/4 in.)
for conduit but I plan to use a heavy plastic kids drinking
straw, tilted down on the outside, and plugged with some
silicon seal at each end where the wire enters and exits.
Ummm... is this an existing hole are you going to drill a new hole?
The modern windows that I've seen have the glass extend almost to the
edge of the frame with only a sheet rubber spacer in between. You're
highly likely to drill through the glass if you decide to drill the
frame.
I may even try loading the window
frame (aluminum, 5 ft x 5 ft (approx)) using a handy
sheet metal screw for the connection.
With 5 watts, that might work. Forget about building a magnetically
coupled loop. You would need to split the frame at some point, and
install a variable capacitor. That's probably not going to happen.
If your window proves to be uncoated glass (unlikely), you might
consider two squares of aluminum foil on both sides of the window to
couple through the RF via a ladder line. You won't get much
capacitance so it won't work on the lower frequencies, but should be
tolerable for the higher bands.
A reminder -- the ground system will be tuned counterpoise
wires running along the wall inside my apartment. I have an
MFJ-1623 tuner which will handle tuning the antenna and
the counterpoise in a very nice compact arrangement with
only one meter to watch!
Good, you have a tuner. However, that's designed specifically to
handle a 12ft balcony mount HF antenna. I don't know what it will do
with a longer antenna. Looking at the schematic:
http://www.mfjenterprises.com/pdffiles/MFJ-1623.pdf
it seems to be a crude L match, which isn't going to match every
combination of reactance and frequency. The meter does NOT indicate
VSWR, so you really won't know if the tuner is effective. My
guess(tm) is you're going to purchasing a more elaborate antenna
tuner, a VSWR meter, or using a 12ft piece of wire.
I once used a large sheet of WELDED chicken wire under the carpet for
a "ground". It has to be welded to prevent the galvanizing from
forming diodes. It sorta worked but nobody wanted the lumpy carpet.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558