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I wanted to do a little research before I replied regarding the 50 vs 75 ohm impedence issue, The atached quote should suffice.
Q. I thought RG6-U coax was not as good nor compatible to use as antenna cable for scanners. Is it also a good choice for transmitters in the 158.00MHz range? Thank you, Jim
A. This common misconception originated in the early days of scanner listening. Many misguided folks use long lengths of lossy RG-58/U coax for scanner reception (and VHF transmission) just because it has a 50 ohm impedance, convinced that coax of any other impedance simply won't work. The fact is that while a proper impedance match is desirable to avoid resistive losses through the inner dielectric (insulation) from high voltages which develop during a mismatch, very few antenna systems exactly match 50 ohms anyway, especially over wide frequency excursions. Although RG-6/U is 70 ohms, not 50 ohms, its low-loss characters tics more than make up for any theoretical impedance mismatch. If you substitute 100 feet of RG-6/U for RG-58/U in scanner monitoring above 30 MHz, I can guarantee you better reception, and the higher in frequency, the more the improvement. I use RG-6/U exclusively for my VHF/UHF monitoring, and use RG-58/U only for shortwave where its losses are not that severe. Coaxial cable, by its very construction, is virtually immune to outside electrical interference. The best shielded coax is always the better choice, and RG-6/U is very well shielded. It also has less loss in its dielectric (inner insulation) than competitive cable types. So that's the long answer which could have been shorter--"Yes!" Coax can be run underground, through water, alongside power cables, near satellite dishes and other electronics equipment without picking up interference. Try to keep it as short as possible, however, to avoid resistive losses from the longer lengths.
This link is for radios in addition to vhf marine, I must say though that I have about 3 yrs of telecommunications and radio training regarding vhf signals SNR SWR, The only point I was making was that it is possible to use Rg6 without problems. I contacted Uniden who makes Vhf marine radios and they recommended Rg59 which is an inferior grade of coax used 20 yrs ago in homes. The benefits it has makes up for any propagation loss.
Last edited by dflyin1; 04-18-2008 at 11:40 AM.
Reason: adding link and comment