[TowerTalk] Yagiis

[jeremy-ca]

Sounds like a Hi Gain, they always liked to add extra elements.
I built PV 4el on 10/15/20 in 1983. They  performed right by the published 
curves and I used a (compensated) severe taper on 20M. BTW, its a 40' boom 
on 20M.

They are not as broadband as some newer designs and mine were cut to 
resonate about 100 kHz up from band edges on 20/15. VSWR got above 2:1 in 
the upper reaches of SSB bands. On 10 VSWR 2:1 bandwidth is about 900 kHz.

Some have complained about narrow FB bandwidth but I would subjectively say 
Ive not seen it below 20dB and its in the 30's at 100 kHz of center 
frequency .  When stacked 4 high (40/80/120/160') and I could select upper 
pair, lower pair and all 4 the FB sometimes went into the noise. Amazing 
what happens when the angles are perfect. The ability to independently 
rotate all 4 made for some interesting signal enhancements especially when 
signals were coming in SP/LP at the same time or even skewed.

I also had 3 stacked on 10 and 15. These days Im down to one on 10/15 and a 
3el on 20. Got out of the contest rat race and constant rotator maintenance.
Even took down the KLM 4el 40 at 180', talk about a maintenance headache! 
That may go back as a pair of 2el.

Carl
KM1H




----- Original Message ----- 
From: "Tom Rauch" <w8ji at contesting.com>
To: <towertalk at contesting.com>
Sent: Friday, June 01, 2007 9:26 PM
Subject: [TowerTalk] Yagiis


> What's the latest thought on Yagi antennas?  Is the old work
> by Lawson on Yagis still considered accurate so far as boom
> length, number of elements, and gain?
>
> Or is there some newer information that casts doubt on his
> work?
>
> I'm going to play with some 34 foot boom 20 meter antennas.
> They were originally 5 elements but it looks to me like I
> might as well throw one element in the dumpster.
>
> 73 Tom
>
>
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