You might also consider Time Microwave LM400UF (Texas Towers and others have
it.) It's another semi-flexible foam-filled low-loss coax. Price is
comparable or better than 9913F.
I think the numbers speak for themselves on 2M and 6M. You want the
lowest-loss coax you can afford (some free CATV hardline would be even
better, but you'll need some baluns.) For the extra $35 or so that the 9913F
or equivalent will cost you over the RG/213, you're getting over 200 watts
more on 10M. At a conservative 6dB gain for the beam, that's the equivalent
of over 800 watts, which is about the cheapest extra power I can think of.
Go for it, and keep an eye out for some free hard line for that run, too. It
doesn't look like anything more than RG/213 is needed for 80M and 160M, so
you can save some money there. It's a toss-up for 40M, but you can probably
use RG/213 for that, too.
Consider yourself lucky. My run of LM400UF is about 260 feet to the base of
the tower. From there, I had to use RG/213 for the remaining 80 feet to the
top. The so-called ultra felxible low-loss stuff was too stiff for my
rotating tubular crankup. If anyone would like to compute the losses at 10M
for that combination, feel free -- it isn't pretty. Hopefully, next summer,
the long run gets replaced with hardline.
73, Dick, WC1M
-----Original Message-----
From: Scott.Neader.KA9FOX. <neader@centuryinter.net>
To: towertalk@contesting.com <towertalk@contesting.com>
To: <towertalk@contesting.com>
Date: Sunday, November 30, 1997 11:12 PM
Subject: [TowerTalk] Right coax for my station?
>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)
>
>-------
>
>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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>KA9FOX Contesting and DXing Site: http://www.QTH.com/KA9FOX
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>
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