Dave,
If you ground the top of the wire of a quarter-wave sloper to the tower
and feed the bottom of the slant wire instead (assuming a ground rod and
some radials laying on the ground at the feed point) you will IMHO do
much better. Some matching may be required at the feed point but it may
be no more than a series capacitor to remove the reactance of the wire.
There my be a very slight bit of directivity in the direction of the
slant wire, but the overall efficiency of this as a TB radiator may be
significantly better even with a short tower of 50-60 feet. If the
tower is more than 60 feet tall and with a beam on top I would suggest
shunt feeding the tower with a cage feed again assuming you can have at
least 4 or more radials on the ground even if you need to fold or bend
the ends a bit to fit in your yard.
All half slopers from metal towers do IMHO is try to backward excite the
tower with RF. Losses can be high and performance is generally less
than adequate. If you are able to shorten the slant wire to get your
feed point closer to 50 ohms may also be beneficial and should also be
considered.
Good luck,
Herb Schoenbohm, KV4FZ
On 3/16/2012 10:57 PM, David Novoa, W4DN wrote:
> Has anyone in this reflector installed a Cushcraft MA-160 short vertical
> with a couple of elevated radials or the K2AV Folded Counterpoise? If
> so, results? Any recommendations? I need to do something before the TB
> season ends. My quarter-wave sloper doesn't work properly.
> Thanks,
> Dave, W4DN
>
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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