At 09:37 PM 5/4/98 -0700, you wrote:
>
> Just wanted to get the word out about a new 80 meter beam design by W7CY
and NI6W.
>
>Photos and more info can be found at http://www.ulio.com/ants.html
>
> Check it out......
Still not good for small lots as the boom is 80' long. I do like the idea
of full size elements.
I have tried one design that worked and found another by antenna pioneer Rex
Bassett. Rex is know for his helium sealed mobile coils and his pre-war
beams...the one that first worked Tibet!
I tried a design that W6SAI featured in his CQ article in the early 60's.
This was the G3PTV array. I tested it out on an old Fortran based antenna
modeling program. It originally had two square dipoles. I found that even
with dual feed it was directive slightly but no gain over a dipole at the
same height. I switched the array to a yagi reflector (Create 57') and one
of the square dipoles (full size) for the driven element. I used part of an
old TET 3 el 40 for the boom and the part of the square dipole. Instead of
being square I made it rectangular with 40 foot elements from the boom and
21.6' wires between the 40 foot elements. This element tuned to almost 3.8
on the first try. I set the Create on 3690 and had about 70 Khz of 2 to 1
SWR bandwidth. It cut over about 3750 and 3830 to not really being a beam.
The elements were both driven by 300 ohm transmitting line with a half
twist. The model showed about 3.0dbd over a dipole and in practice it was
at least this with about 12 db F/B. F/S was 35 to 50DB (pattern over real
earth showed some interesting side nulls). It looked like a 3 el beam with
two 40' elements and one 57' elenment from the ground. The plus was it
worked well on 160, too (gee thats 2 80 meter elements fed together so makes
a 160 antenna of sorts). Stayed up one year and became unstable...now if
someone would donate a 5 el KLM 20 boom and 2 elements......and I had
another tower!!
The second antenna was used by Rex Bassett. He actually used his 80 meter
mobile traps and made a small beam (he used 24' spacing). This was written
up in a mid 50's CQ. The elements with the mobile traps were only 35'!!!!
But it worked. Rex worked VK on 75 meter AM most mornings when no one else
could. In those days most of us worked 3800 to 3820 so did not need much
bandwidth (he said 40Khz bandwidth). The VK's were on 3690 to 95. He
actually had two of the beams..one for 3.8 and the other for 3.95 for
ragchew and nets. The only other guy I remember who compared with him was a
guy with two full size 80 verts phased. He was 1 S unit below Rex most
mornings. I don;t remember Rex after SSB became the phone mode. He did
work Europe one night with W1BU and they were both 5-8 to 9. Nobody heard
and worked Eu better than W1FZJ Sam at W1BU on AM in the late 50's and SSB
in the early 60's.
All I could do is sit and wish and hope the DX could at least hear my lil
dipole.
73 Dave K4JRB
You have not worked low band DX unless you have tried several projects and
have the parts laying in your backyard or basement. Of course if they stay
up they are not BIG enough!
>
>
> ********************************************
> Richard Hallman N7TR N7TR@RNODX.ORG
> 11870 Heartpine St
> Reno NV 89506 EX: KI3V, HL9RH
> 702 677-1106 A92FN, N3AMK
> *********************************************
>
>
>
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