N2EA wrote:
..."Assuming you could efficiently match it and deliver power to it.
Figure 3dB loss in that scheme, and you'd net out with 7 or 8 dB fwd
gain, and a beamwidth which won't span europe. "...
Could be. I didn't include matching network loss or transmission line
loss, and for an antenna that covers 1200 ft that could be significant
(if you don't want to spend a fortune on coax).
Can you imagine trying to work with a fixed antenna that has a bandwidth
of 12 or 13 degrees? That's worse than the guy who built the 12 element
Sterba curtain for 20 meters (18.6 degrees). He already had it up, knew
the direction it was pointed, and wanted to know who he could work with
it. There were only a few countries where it was better than a dipole,
a few Russians, EP, YA, AP, VU, VU7, VQ9, 8Q, S7, 3B6, 3B8, 3B9, FR, FH,
5R, and KC4. It would be interesting to figure the same info for the 9
element Bobtail.
Jerry, K4SAV
jim Jarvis wrote:
> KZ4USA wrote:
>
>
>
>
>>Anyone ever take two or maybe three of these and make a 9El
>>vertical array.
>>
>>If you had the room would it outperform a 3El yagi for 80 meters in
>>one direction?
>>
>>Just wonder.
>>
>>KZ4USA
>>
>>
>>
>>
>>
>>
>
>You will need a space of about 1200 feet to build it and a method of
>accurately aiming it, 11.3 dBi gain, beamwidth 12.2 degrees.
>
>Jerry, K4SAV
>
>To which N2EA appended:
>
>Assuming you could efficiently match it and deliver power to it.
>Figure 3dB loss in that scheme, and you'd net out with 7 or 8 dB fwd
>gain,
>and a beamwidth which won't span europe. Plus, with 9 el, you'd have 8
>rear/side nulls/lobes which were maybe 10dB down from the fwd lobe.
>Yagi pattern would be cleaner.
>
>If you were to add the price of copper into a spreadsheet model, and
>plot
>$Cu/dB, you'd likely find things would optimize around 3 or 4
>vertical elements,
>in some configuration.
>
>Unless you had a specific reason for a rifle-shot, you'd be better
>off with
>something simpler to match and control. Like putting the money in
>steel instead
>of copper, and trying a pair of switchable, crossed inverted vees at
>100'?
>
>Good question. Good modelling. KISS?
>
>73/n2ea
>
>
>
>
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