I have used similar antennas for years. If you have only one pole or
tree, then use it in a diamond shape. Tie the corners out with string
if you do not (or cannot) use a horizontal spreader.
The bottom of the diamond should be as high off the ground
as possible, but for a long time I used a 40m loop as low as 3 feet at
the base. To get that clearance I had to drag the bottom of the loop
sideways about ten feet from the metal pole.
Oh yes. Why not feed the thing at the top if you can (applies mainly
to diamond versions)? I now use heavy duty ladderline which goes to a
balun outside my home. Its very much lighter than coax and has low
losses. Then I have 20 feet of RG-8 from the balun to the 253 ATU.
The 20m diamond with its base 20 feet up (fed at the base before I
knew any better) was a flame thrower. It was several S points better
than a half wave vertical with 80-odd radials. I used the 40m diamond
to work D2CW on all bands 160-10, but 160 was pushing it a lot. It did
work fairly well on 80 (VR6BB first call) and it was certainly good on
40/30.
John G3JAG - recuperating from Dayton.
On 20-May-99 Leonard J Popyack wrote:
>
> Since I wrote this up for one guy who was interested in my antenna,
> I will
> share it with the group. 73 Len WF2V:
> -----------------
> Could you describe your loop for me?
>>I need something like that.
>>Thanks.
>>Bill W5EC
>
> you bet. it follows the basic formula 1005/14.100 for total length
> (about
> 71 feet, 3 inches more or less -- I added about 1 foot to this for
> placing
> rope holder loops in each corner).
>
>
> o--------o
> | |
> | |
> | |
> o----v---o
>
> just make a one or two turn loop in each corner of the square, so
> that you
> can hook rope to each corner. the "v" is an insulator. You can just
> hook
> your 50 ohm coax up to each side of the wire, or better yet, place
> a short
> section of 75 ohm coax as the first 8- 10 feet of coax leaving the
> loop,
> then into 50 ohm coax. This is what I do. I think i use RG-6 for
> the
> matching section. But these things work ok by simply connecting to
> them.
>
> Good luck. This was a field day antenna for our group which I
> slapped up 3
> years ago. Needless to say, I never took it down!
>
> 73 Len
>
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To: <tentec@contesting.com>
Date: 20-May-99
Time: 22:34:27
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