I currently use European PMR - Private Mobile Radio, (called FRS-Family Radio Service in the US). This is fine for the short distance bike to bike and bike to car comms. that I have used it for, but due to the high operating frequencies (446-467MHz) and low power, only works reliably when you can see the other vehicle (no terrain blocking the line of sight) and then only up to 2-3k.

It has it's plus points; cheap ($80/GBP50 per person), widely available, legal (in many developed countries), compact, standard batteries & I guess hard to detect where used illegally, due to the low power.

My current set-up is as follows:
----
Cobra PMR ($30/GB20), due to the standard headset connection, keylock function & price. (NB the MT700 model has pillion intercom facility too).

Bike headset ($25/GB15) with bar-mount talk button
http://www.maplin.co.uk/Products/Mod...eNo=27212&MR=N

Koss 'The Plug' earphones $25/GB15, as when riding at speed, or with earplugs, the standard speaker in the bike headset is inaudible.
http://www.fixup.net/tips/earbud/30d...d_earphone.htm
----

However, it would be useful to have a radio with a range of at least 20k, to allow a different pace/itinerary between vehicles and for rider to base camp comms- NB I'm not talking about places with mobile phone coverage.

Does anyone have experience of a radio system that will achieve 20k or more, where at least one of the 2 radios must be hand-portable for use on a bike? (I could probably live with a bit less between bikes & can put a 'full size' radio in the 4x4) Will CB do this? What about marine VHF?

Any ideas or experience would be appreciated.

Thanks,

Ian