How can I maintain contact with mobile person

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Hi Steve,

to have continuous comms over 300 mile range you'll need think NVIS on 7Mhz or 3.5Mhz band. These will give you long term reliable communications.

5 or 10w power is the lowest to consider for reliability.

Morse code will be easiest and least expensive kit wise. Spoken word by SSB will be possible too but at extra cost.

You mentioned that large antennas are ok as long as they can be stowed. The antennas neded for these frequencies and for this technique are long horizontal wires than need to be rigged 6 to 20ft above the ground. Easiest is to use end fed half wave antennas. Using thin wire, this can easily be spooled on coarse fishing tackle trace holders for easy storage. Deployed length of the antennas is approx 20metres long for the 7 MHz frequency and 40 meters long for the 3.5 Mhz frequency.

End fed antennas are deployed APPOXIMATELY horzontally ( perfection is not important not do they have to nbe in a straight line). I do this by attaching a weight to the end of the wire and throwing it over tree limbs, bushes etc.

Why two frequencies? Well long term the 3.5Mhz frequency works best in hours of darkness and the 7Mhz frequency works best in daylight hours.

Kit you'll need are transmitters ( cost range £120 to £600), Antenna matching units (budget £120) and thin, insulated wire for teh antenna ( say £10.00)

The more expensive transmitters in this range will support both voice and Morse code transmission, and will operate on many more frequency bands. Suitable radios are the Yaesu FT817 and if you are lucky enough to find one the excellent Icom IC 703 which is my personal favorite. The 703 combines an Automatic Antenna Matching unit into the radio itself, which makes for easier carriage and deployment.

With this type of setup I reliably communicate over the distances you are planning for, and do so using my station in protable configuration.