"Tom Corker" wrote in message
oups.com...
OK, I've built my J-pole and it's looking quite good. In the end, I
went for 22mm copper tubing as I had some spare. I've still not
decided on the coax though. I've measured the run, and I'll be needing
12 meters (39 feet). In addition to the RG213, I've managed to find a
source of 'low-loss mini 8' (RG-8X). The RG213 is £1.40 per meter, and
the RG-8x is £0.65
per meter. Is the RG213 worth the difference on VHF?


Tom,

On VHF FM, a dB or two of signal will affect a marginal contact. In your
situation, however, the better cable provides only slightly more than half a
dB of signal, hardly worth the extra expense.

I used http://www.ocarc.ca/coax.htm for that comparison.

Other comparison tables and charts are widely available on the Internet with
a search for "Coaxial Cable" Loss. The sample table below will line up
nicely in a monospace font, like Courier.

Coax Cable Type Signal Loss per 100 ft
Loss* RG-174 RG-58 RG-8X RG-213 RG-6 RG-11 RF-9914 RF-9913
1MHz 1.9dB 0.4dB 0.5dB 0.2dB 0.2dB 0.2dB 0.3dB 0.2dB
10MHz 3.3dB 1.4dB 1.0dB 0.6dB 0.6dB 0.4dB 0.5dB 0.4dB
50MHz 6.6dB 3.3dB 2.5dB 1.6dB 1.4dB 1.0dB 1.1dB 0.9dB
100MHz 8.9dB 4.9dB 3.6dB 2.2dB 2.0dB 1.6dB 1.5dB 1.4dB
200MHz 11.9dB 7.3dB 5.4dB 3.3dB 2.8dB 2.3dB 2.0dB 1.8dB
400MHz 17.3dB 11.2dB 7.9dB 4.8dB 4.3dB 3.5dB 2.9dB 2.6dB
700MHz 26.0dB 16.9dB 11.0dB 6.6dB 5.6dB 4.7dB 3.8dB 3.6dB
900MHz 27.9dB 20.1dB 12.6dB 7.7dB 6.0dB 5.4dB 4.9dB 4.2dB
1GHz 32.0dB 21.5dB 13.5dB 8.3dB 6.1dB 5.6dB 5.3dB 4.5dB
Imped 50ohm 50ohm 50ohm 50ohm 75ohm 75ohm 50ohm 50ohm