ExplorOz Team replied:

Narelle,This is a good question and one which we will have to add to our trip preperation section. In a nut shell simplex is the mode of operation which means that you transmit and receive on the same frequency. Duplex means that you will transmit on one frequency and receive one another. OK, so what does this all mean.In most major cities and in certain rural areas repeaters have been established that allow you to talk over a greater distance (this works in duplex mode) - how this is acheived is that you talk the repeater station picks up your signal and then retransmits it on a different frequency. Hence the difference in the frequencies in duplex mode (If you transmitted and received on the same frequency you would over talk your own signal) - I hope this is making sense.Duplex mode is usually configured for channels 1 - 9 and uses channels 31-39 as the duplex frequencies. If you wish to check for a repeater then set your radio for duplex mode on channels 1 - 9 and press the button on the mic - most repeaters will respond with a tone or noise after you release the mic key (if you hear nothing then you cannot reach a repeater). If you get a tone back then try to talk to someone you may find that you are talking to someone who is quite a way away from you. Simplex mode means that you transmit and receive without the aid of a repeater (shorter distance transmission) If you are in a group and wish to talk with each other then you will use simplex mode i.e each user will select a none duplexed channel and you will talk to each other directly on the same frequency.I hope this helps and does not confuse. Good luck (dont worry it is easy just have a go and see what you get - You will have it in no time)

mark Callaghan replied:

Hi Narele We use UFH to communicate with drivers on all of our tag-along tours as sometimes our groups spread out over several Kms. Its not uncommon to talk to someone over 80 kms away. ŒŒSome little extra on this that you may find usefulŒThere are several channels that are used around the placeŒCh 40 is used by truckies - you can find out about road conditions etc from these guys - but they do use colourful language Ch 5 - the emergency channel - usually monitored by volunteers in major centres Ch 6 - community channel Just set your unit to scan and it will pick up other users in your area. Remember that UHF is an open system and that your conversation can be heard by anyone Now for the plug - check out our web at http://www.4wdadventuretours.com.au hopefully well see you on tour.