Posted by
Rick WA6NHC-2 on
Feb 25, 2018; 9:52am
URL: http://elecraft.85.s1.nabble.com/Re-KPA500-faulting-on-high-VSWR-on-power-rise-tp7638513p7638565.html
Hi Erik,
I'll keep this short as the thread will likely be closed soon (or
should). What I have up now is Field Day style, simple antennas (the
inverted L for example, an 80M dipole, R7) shot into the trees so I
could get on, pending the install of 'the real station', hi. The water
pipe (300+' in two directions, deep enough to never freeze) is the L
counterpoise, for now. It isn't ideal but it works and isn't meant for
forever.
I will be installing a lightning protection and counterpoise system with
lots of copper, ground rods etc, which will come to box (for feed line,
rotor control) at the tower end of the conduit to the shack (AND tie
into the house grounding per code). The box will have hardline from the
house, coax for the tower, matching network for the Inverted L and the
surge and lightning devices on each feed (static or lightning stays
OUTside). I'll also put an AC power outlet at the base, for occasional
power tool use and a wifi web cam (may as well, I have to power the
electric winch motor).
I DX, I don't contest, so I don't need SO2R (other than the second rx
for DX chasing on splits). Should that someday change, I'm blessed with
the space for a tower farm or I'll put the EDZ up (kind of a favorite, I
worked a LOT of DX on that dipole). With the KAT500 (or KPA1500), rapid
QSY isn't an issue on the EDZ.
No slam was inferred or taken on the Cushcraft; only that the
compromises add up to make it work, but not as well as a tuned dipole.
I'm not sure that an end fed wire antenna will work well on multiple
bands without a fair amount of effort (remote tuner at least, absolutely
a CMC to back that up). The voltages at radical SWR (non-resonant
afterall) can be high. Isolating the radiation to the wire is a major
issue, that antenna tends to want the feedline (coax commonly) as the
counterpoise, bringing RF into the shack (and why I went with the
inverted L which partly warms the worms).
73,
Rick NHC
On 2/24/2018 10:53 PM, Erik Basilier wrote:
> Your antenna farm is a separate subject, as is mine, and in this thread I will just comment briefly on those subjects. I got interested in SO2R, but don't have space for two towers/beams. You may not be thinking about SO2R, but if you are, and if you too can't put up a second tower/beam, then you might want to think twice about using SteppIR. With a beam that can work multiple bands without retuning, I use a multiplexer that allows two transmitters to use the same beam as if I had two separate ones. (Minus the capability to point them in different directions!). If an end-fed wire antenna works well without tuner on multiple bands, it can also be used with a multiplexer to perform instantly on another band, without retuning. Not so with a simple center-fed dipole (but a fan or trapped dipole would be ok). My other comment is about your verticals fed against a pipe in the ground. When I was using inverted L's for 160 and 80, I first tried them against a single, 4" wide copper strap going part way around the house and tied to a few ground rods here and there. Then I tried it against two zigging wires used as elevated radials. This worked much much better. Like others have said so often and so well: If you are going to bury radials, it will take many of them.
>
> 73,
> Erik K7TV
>
>
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