Ed,
Good points – although if one were to do a 2 el it would quite nicely compete
with a beverage on receive (RDF’s very similar) so I’d not downplay its FB.
As for an elevated 4 sq... I had thought of that... will need to get into it
more to see if that might be the best overall way to go.
thanks,
Gary
K9RX
Its an interesting thread. A few comments.
- Its all about gain. You don't care about F/B because if you canconsider these
antennas, you are going to have beverages. And if you havegood beverages, you
will essentially never listen on your TX antenna again -except for certain
specific circumstances.
- If you have negatively sloping terrain of ANY kind towards EU,you need to
HFTA model it. Not NEC antenna model it. You do NOT have tohave the specific
data. You can create your own ray data to see what the effect will be. You do
NOT have to have the specific info to understand the effect of that slope.
Estimate it, and you will see the effect.
- 80M yagis are notoriously difficult to maintain, so personally,with negative
slope to EU, if budget and space are no object, I would do anelevated 4 square
- of 4 - 85 ft towers with the insulated adapter at the 20foot level. Do 4
radials under each one and then lay out a full groundscreen (ala K3LR style) in
the full square area of concern (essentiallyunder all area that has a radial on
it). That way you really don't carewhat your ground conductivity is.
Ed N1UR
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