HF v Satphone v CDMA

[LOADEDDOG]

I have been talking to the organiser of the Variety Bike Run and he would like some feedback on the best type of communications for the run.
they require car to car coms over 50 - 100 kms for both general and emergency communication through out the wheatbelt from New Norcia to Beverly.
The options they are considering are :
HF
SATPHONES
CDMA

ALL COMMENTS AND OPINIONS WELCOME

[vk6hgr]

I have been talking to the organiser of the Variety Bike Run and he would like some feedback on the best type of communications for the run.
they require car to car coms over 50 - 100 kms for both general and emergency communication through out the wheatbelt from New Norcia to Beverly.
The options they are considering are :
HF
SATPHONES
CDMA

If there's adequate CDMA coverage through the whole route then it's probably the cheapest option. The problem with CDMA and Satphones is that every phone will have to be preloaded with every other phone's number which could be quite a task

HF and Satphones have a high equipment cost and sometimes uncertain coverage, but when they work they should provide full coverage. HF is affected by the time of day it's used (may need to lease a few channels) and a relatively high operator training requirement to work the radio whereas Satphones are similar enough to 'normal' phones but don't work so well without a perfectly clear view of the sky.

Whatever technology you use it wouldn't hurt to also install UHF CB radios in all the vehicles for general car to car chatter within 3-5Kms of each other. In an emergency messages can be passed car to car fire bucket style.

[Nick]

The problem with HF is that unless it is set up for NVIS (near vertical incidence skywave) the signal will travel over the top of where it is needed. If chosen will need setting up at the base and mobiles as a short distance ( NO skywave type installation) . Hf IS GREAT but 0 to 300 km can be very difficult at times