Topband: Inverted L Questions
Tue, 28 Nov 2000 10:17:47 -0600
Greetings Topband Gurus.
I need to tap some of the collective wisdom of The List as I am soon
about to embark upon my "160 m from a city lot" adventure.
Initially, I think that the weapon of choice will be an Inverted L for
both transmit and receive. I don't have room for much else (Beverages,
etc.) at the moment. I do have a couple of trees that will give me the
50-60 vertical feet and 100 or so horizontal feet that I need to string
it. Is there a formula for figuring the length or is "in the ballpark"
I have acquired a ~600-1800 pF variable cap of the air-dielectric
variety (refugee from an old tuner I think) which doesn't have much
plate-plate spacing but I think that it'll work. I have no amp so I'm
hoping that 100 W won't make it arc. Am I off in the right direction?
I hope to feed it with some RG-58-type coax as that is the only run I
have that is long enough to get from the shack to the antenna feedpoint
tree. Will this type of coax be OK? I have assumed "yes" since I don't
think that it will attenuate too much 1.8 MHz energy in the 100 feet or
less that the run covers. Is this a safe assumption?
Finally, the ingredient I am missing now is wire. As my wife and 2.5
small kids are still fond of eating and keeping the house heated, my
radio budget isn't exactly huge. I have officially put in my request
with Mr. Claus for one or two 500' spools of 12 gauge solid copper wire
(with black insulation for low neigbor-observability) which I am hoping
will serve equally well as both the radiator and the (buried?) radials.
This is where I really need the info. Is 12 AWG solid sufficient?
Would bare copper be better? What about the radials? Does insulated
wire work OK in this role? I can realistically only get two or three
1/4 wave radials in the ground. I might be able to get a few more 1/10
wave wires in the ground. Advice?
Please forgive all the verbiage for such an un-impressive setup. I just
want to get this done right the first time in my limited available
antenna construction time (the XYL does NOT understand) so that I have
something that will play on 160. With no special RX antennas and only
100 watts, I know that I will not be a Force To Be Reckoned With but I
at least want to be able to get in the game. I am going to miss ARRL
160, unfortunately, but perhaps there is hope for Stew Perry. I suppose
that I'll have to start going to bed early, too, if I want to cash in on
the darkness just prior to sun-up...bad news for a life-long night-owl
Thanks for any wisdom that you can pass along. I enjoy reading all the
stuff that you wizards kick around on this reflector. I've learned a
lot just by lurking.
73 from Nashville, Tennessee.
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