[TowerTalk] Right coax for my station?
Scott Neader KA9FOX
neader@centuryinter.net
Sun, 30 Nov 1997 19:42:38 -0600
OK, guys, you aren't done with me yet! The tower is up, and the beam is
pretty much ready to be raised to the top. BUT, I still need to buy coax
cable!
Most guys I talk to are using RG-213 or are the hard core types with 7/8"
Heliax. I'm thinking about using Belden 9913F (tnx WE9V for the idea). It
is like the typical 9913, but instead of an air dialectric, it is filled...
and it is more flexible.
About the install: My tower is 72 feet tall and roughly 25 feet to the
radio room. The C4XL beam takes two feed lines (one for 10-15-20, and one
for 40), plus I'll need runs for a two meter beam (and maybe 6m), and
whatever I decide to do for 80m and 160m.
My question is... is the 9913F overkill, especially for whatever I do on
80m and 160m (and maybe even 40m)? Should I go with the cheaper RG-213 for
the lowbands? The AES catalog has the 9913F for about 60 cents per foot,
compared to about 37 cents per foot for RG-213. More info about the Belden
9913F:
Per Belden, in latest AES catalog:
--------
New 9913F High-Flex RF Transmission Cable: This low-loss RG-8/U type
coaxial cable is a high-flex version of Belden's popular 9913. It offers a
stranded center conductor for improved flexibility and flex life, a
patented high-flex cut and abrasion resistant jacket and a high felocity
foam insulation
* CENTER CONDUCTOR: 10 AWG (19x23) .108 bare copper (stranded)
* INSULATION TYPE: Foam Polyethylene (cellular polyethylene)
* JACKET TYPE: PVC
* SHIELD: Duobond II + 90% tinned copper braid; 100% foil shield
* NOMINAL IMPEDANCE: 50 ohms
* VELOCITY FACTOR: 83%
* DIAMETER: .405 inch
* NOMINAL CAPACITANCE: 24.5 pF/ft.
* LOSS PER 100 FT: 1.3db @ 100Mhz, 2.8db @ 400Mhz
Amateur Electronic Supply PRICE:
100 feet roll: .80 cents per foot ($ 79.95/roll)
250 feet roll: .64 cents per foot ($159.95/roll)
500 foot roll: .60 cents per foot ($299.95/roll)
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Chad, WE9V, was nice enough to run these numbers for me, for comparison of
different cable types:
150' run on 10M, 1500 watts to coax:
7/8" 50 ohm 1439 out
3/4" catv 1371 out
9913 1202 out
RG-213 991 out
RG8X 778 out
For 80M, 150' run, 1500 watts
9913 1385 out
RG-213 1320 out
RG8X 1186 out
For 2M, 150' run, 50W to coax
7/8" 50 ohm 45 out
3/4" catv 40 out
9913 28 out
RG-213 19 out
RG8X 10 out
-------
Thanks, in advance, for your advice!
73 - Scott KA9FOX
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Scott Neader (608)788-1234 / FAX (608)787-0100 / neader@QTH.com
3323 South 29th Street, La Crosse, WI 54601
KA9FOX Contesting and DXing Site: http://www.QTH.com/KA9FOX
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