Jerry
Thank you for this information, it is exactly the kind of information that I am
looking for.
Yes, I am totally alert to the fact that anyone can claim anything on the
internet, unlike in the old days when there was a lot of peer review and you
just could not publish without being scrutinised.
Means that I will need to go to plan B and that is put up a rotatable dipole
except it will be in a permanenet fixed direction.
Question will now be if I go with the CushCraft or the Hy-Gain. Unfortunately
neither of these can be viewed locally and by the time they are landed here
they are about triple the US price. I am gving serious thoughts towards just
obtaining the crucial parts ( synthetic parts ) and then homebrew the rest.
Fortunately the biggest aluminium wholesaler is just 3 Km down the road from
here.
Input towards this idea will also be appreciated,
73, Marinus ZL2ML
> From: K4SAV
> Subject: Re: [TowerTalk] Linear loaded KE4UYP vertical
> To: towertalk@contesting.com
> Message-ID:
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Don't believe everything you read in print. I just modeled an 80 meter
> version of that antenna, using the recommended dimensions, top wire at
> 31 ft and 65 ft long, with 82 ft of wire in the vertical portion with
> the bottom wire 5 ft above ground.
>
> It resonated at 3.69 MHz with an impedance of 26 ohms. He claims the
> longer wire on the vertical side off-center feeds the antenna and raises
> the impedance to 50 ohms. Didn't work for me. If you matched the
> antenna to 25 ohms the 2 to 1 SWR bandwidth would be about 70 KHz. (He
> claims 300 KHz). The gain is 2.9 dBi straight up. (He claims 1 dBi.)
> 2.9 dBi is about the same as an 80 meter dipole at 18.5 feet. He claims
> it is 80 to 85% efficient. EZNEC calculates 4.13 dB loss. That's
> equivalent to 38.6% efficiency. He claims it is totally
> omni-directional. At 30 degrees elevation it has a F/B of 3.6 dB.
>
> I didn't include the feedline or any metal support poles in the model.
>
> I didn't do the 160 meter version, but I would expect much poorer numbers.
>
> Jerry, K4SAV
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