Bob E wrote:
OK, Bob E - it appears that the ball is in your court. In the interests
of peace and harmony, and to prevent confusion, please could you please
tell us exactly (and I mean EXACTLY) which RG-6 vs RG-6Q parameters you
are concerned about?
Ian

OK, thanks for the discussions.

I have a VHF/UHF omnidirectional antenna with integral amplifier for TV
reception:

http://www.amazon.com/Antennacraft-5...mplified-HDTV-
Antenna/dp/B007Z7YOKS

Several broadcast towers surround me, from 40 to 50 miles:

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d5b9405cba93e1 5

Terrain is pretty flat.

The antenna is currently connected to RG6 located indoors, up high in a
1-story cathedral-ceiling home. Signal reception is marginal, gauged by the
HDTV's (relative) Signal Strength display; dropouts occur regularly on some
channels.

I plan to mount the antenna outdoors on the peak of the roof. I was planning
to use RG6 quad-shield, but wanted to check whether it is truly a better
solution or not.

Cable run indoors now is about 50 ft. From the roof location this will
increase to 75 or 100, depending on the route I choose, hence my question.

Thanks.

When you have an antenna with integrated amplifier, the loss of the
cable normally will not be a prime concern. Of course this only holds
true when the antenna+amplifier is well designed. I don't know the
situation in the USA, but here in Europe there are only very few good
manufacturers and all the rest sell crap and snake-oil. Don't know what
category your antenna is in.

With a bare antenna (without amplifier), loss is very important as the
signal from the antenna is attenuated and the noise at the input of
the receiver is constant, so your signal/noise ratio worsens.

However, with an amplifier near the antenna, the signal should be raised
sufficiently to be above the noise at the receiver, and the signal/noise
ratio at the input of the amplifier becomes the predominant factor.

In this case, the loss from your coax should not matter too much.
The good-quality shielding is often more important.

Note that in digital TV, the occurrence of dropouts is not only determined
by signal strength, but also by signal quality. This will improve
dramatically when you put the antenna on the roof, especially when this
results in a more or less clear view of the transmitter. What you
receive now is probably a jumble of reflections. While digital TV is
more tolerant to that than old analog TV, it still eats from the margin
that you need for dropout-free reception.