Hi Bill;
We are sorry to learn of the damage to the phasing line, and glad the
horse culprit was arrested! :)
ALL four lines should be equal; wether using one-half wave of RG-213 to
the one-quarter RG-11 75 ohm, or using 3/4 wave RG-11 to all four. The
array should not have a mixture of the two combinations above.
Multiples of 1/4 wave lines, ie, 1/4 wave or 3/4 wave to physically reach
the feed points, should be used.
Comtek Systems stocks 97% shield RG-11 Foam, RG-213, RG-11A and RG-83 (35
ohm for stacks) coax primarily for our customers and amateurs in general.
We can FedEx or UPS overnight for Friday delivery if desired.
Good luck in getting the lines repaired and in CWSS.
73,
Jim Miller, K4SQR
http://www.comteksystems.com
4-Square Experts, Stack Yagi
& Remote Antenna Switching Systems
On Wed, 31 Oct 2001 10:38:24 -0800 (PST) BILL STRAW <wb0o@yahoo.com>
writes:
>
> A question to the experts:
> I have a 40M and an 80M 4 square, each has been up
> 6-7 years. They are both made of Rohn 25, and the
> base of each vertical is elevated 15 feet. Thus, a
> simple 1/4 wavelength 75 ohm phasing line won't
> reach from the phasebox on the ground to the "base"
> of each vertical.
> When I built the 40M 4 square, the then owner of
> Comtek told me to use a multiple of 1/4 wavelength
> 75 ohm coax (I think I have 3/4) so it would reach
> between the box and base. A lot of coax, but it works
> great.
> When I built the 80M 4 square, the owner of DX
> Engineering told me to just use equal lengths of 50
> ohm coax to drop down from the elevated bases to the
> ground, then hook up the 1/4 wavelength 75 ohm coax.
> This also works great.
> Now, I find one of the 40M 3/4 wave 75 ohm phasing
> coaxes is destroyed. (A horse was implicated and
> arrested). It is just 3 days before CWSS and I have no
> way to get any 75 ohm coax.
> Questions: Are these two feed methods equivilant?
> I plan to feed the 40M like the 80M, all I would
> have to do is cut the good 75 ohm into 1/4 wave
> pieces, cut up some 50 ohm coax and solder a few
> plugs. I guess I could elevate the 40M phasebox on
> a pole and string 1/4 wave phasing lines to the
> elevated bases, but the 50 ohm drop down line
> method sure would be quicker.
>
> Any ideas?
> Thanks, Bill WB0O in northern North Dakota, 10 miles
> south of VE4 land.
>
>
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> -----
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>
>
Jim Miller, K4SQR
http://www.comteksystems.com
4-Square Experts, Stack Yagi
& Remote Antenna Switching Systems
List Sponsored by AN Wireless: AN Wireless handles Rohn tower systems,
Trylon Titan towers, coax, hardline and more. Also check out our self
supporting towers up to 100 feet for under $1500!! http://www.anwireless.com
-----
FAQ on WWW: http://www.contesting.com/FAQ/towertalk
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Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
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