Ron Hinds wrote:
Then of the three I mentioned, the RG-8/U would be best?

I think you have completely lost sight of what you are doing. The radio in
question is a handheld device, aka a "Handie-Talkie" or H/T. It is designed
to work with the whip antenna that comes with it.

It may not get better reception or transmission with a larger antenna,
and may actually do worse. The front end of the radio is not designed to
handle large signals and it could easily overload and hear nothing.

Obvioulsy an outside antenna is needed if you are inside metal or poured
concrete (due to the steel reinforcing bars) walls or in a car. In a wooden
or plasterboard house, you may not get a lot of improvement nor need it.

You might think that a high gain antenna will improve your reception, but
if there is a close station or repeater it will just blank out. It does not
have to a ham transmitter, paging, VHF (fire/EMS, etc) will wipe out 2m,
and UHF can disappear under a GMRS or land mobile system.

If you live out in the woods, then a decent outside antenna will help and
a random wire or dipole will help with HF reception. In a big city, the
ferrite bar (up to 7mHz) will be a noise magnet and you many not even be able
to receive anything at all.

As for coax, good quality RG-6 coax will do fine, and you can get it almost
anywhere. Make sure to use high quality COMPRESSION connectors and adaptors.
The radio uses an SMA connector so you will need to get an SMA to F to connect
it to the coax and the antenna will have a PL-259 (aka UHF) or "N" connector
on it so you will need to get the connectors from a specialty shop.

You also want to get an external speaker and microphone as if you connect
up a coax to it, you will destroy the radio. The stress on the antenna
connector will cause it to break, or crack the circuit board it is connected
to. If you epxect to hand hold the radio and talk on it, something stiff
such as RG/213 may not last out a day of activity. :-(

Geoff.

--
Geoffrey S. Mendelson N3OWJ/4X1GM
Those who cannot remember the past are condemned to misquote it.