Topband: Inverted L questions
w2irt at comcast.net
Mon Nov 20 10:47:26 EST 2006
This week my Inv. L should hopefully be going up. Couple of
questions, if I may:
1) What's the best way to match this? I've heard two options...first,
make the wire about 135-145' long and tune out the reactance with a
series cap. Well, all fine and dandy, but where would one find a cap
in the 700-1000pf range, capable of legal-limit operation these days?
I don't have a Trusty Junk Box to turn to for this project, alas.
Second suggestion was use 234/f and match with an inductor across the
feed to ground. I can't find dimensions for this, however. What is
the preferred matching method for those on-list who are using Ls? If
it makes any difference, I'm using a DX Engineering radiail
plate/SO-239 about 30 inches above ground as the feed point.
2) I can put the far end of the L in one of two directions. The
easiest, unfortunately, is northeast (i.e. Europe). Will this be a
problem or is the performance hit off the end minimal? I haven't
measured it yet, but I'm pretty sure the vertical portion is only
going to be around 60-70'.
The only other option is north-northwest, which I'd rather do, but
this puts it almost directly over the top of where I'm planning on
running my K9AY receiving loop in the back year. I'm thinking it's
probably better to separate these as much as possible, yes?
3) The feedpoint is between two closely-spaced trees, whose tops
diverge by about 4 or 5 feet. Could I put a second wire at the
feedpoint and have an 80m vertical going up one tree and the 160
Inv-L up the other? Any idea how I'd match a beast like this if it IS feasible?
Thanks to all in advance.
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