On Mon, 03 Mar 2008 02:57:37 GMT, Telamon
wrote:

In article ,
"Robert11" wrote:

Chances are I will be the only person to answer you that it matters.
Everyone else is of the opinion that it doesn't. You will lose received
signal power with the mismatch and the argument always revolves around
how much the loss is important to your reception.

Since you have the coax use it and if the performance is satisfactory
then I would not worry about it. If the performance is not good enough
then go buy the right impedance coax and for scanners at higher
frequencies the most important factor is loss per foot. You want the
lowest loss per foot in the frequency range you want to receive on.

For short wave the loss per foot is not as significant being in the 3 to
30MHz range. Coax loss goes up per foot at higher frequencies.

Although you will theoretically see losses, the front-end gain of your
receiver is so high that it will compensate for this mismatch. The end
result will be unnoticeable unless the desired signal is at the noise
level (i.e. where the additional 1.3 dB would have an impact). As
noted, the losses will be more negligible on MF/HF versus VHF/UHF.

RG6 does offer some advantages over say RG58/U or RG8/8x cable in RX
on MF/HF frequencies: Good RG6 has a much better shield which will be
more efficient at blocking-off the pickup of unwanted interference.
Equivalent "50 Ohm" cables would be similar to the LMR-400, etc.

______________________

The Traveller
Carlsbad, California