I’ve had an old Clansman PRC-320 for a while now and recently modified it to add lower side band modulation (LSB) to make it more useful on the amateur radio bands. It’s had a little testing at home but with the Christmas holidays starting it seemed like now would be a good time to test it properly.

I bought the radio to use for POTA and SOTA activation’s, however the Clansman fleet of radios was initially designed as the British Army’s combat-net radio system, for mobile military operations so I wanted to give it the test it deserved. The PRC-320 is the systems man-portable HF radio set, designed to be carried on a soldiers back in the field and provide ‘theater-range’ communications from a mobile patrol back to a headquarters somewhere.

With the radio came a patrol bag however this is missing a couple of pouches (now on order from eBay) so at the moment I only have the parts for carrying the radio and the batteries. With this in mind I dropped the kit into an old British Army issue bergan (rucksack) with a dipole kit, the headset, a VNA for testing the antenna and a warm jumper for some comfort.

For the first test I decided to do some milsim and walk (insert appropriate military term here – march, tab, yomp, patrol etc) an 8 mile route from my home to my closest POTA location and back – GB-5078 Warsash Common Nature Reserve & Country Park. The weather was atrocious, rain, flooding, mud and very cold. I arrived soaked and spent a fair amount of time in a sea of mud building an inverted V dipole for the 40m band to test my LSB modification. I resolved to make the minimum of 10 QSOs for a successful activation or operate for 30 minutes whichever came first to avoid hypothermia. Thankfully after 25 minutes of operation I had made 15 QSOs and was able to pack up and wade (literally) home for a warm coffee and shower.

For my second activation I took the same kit – weighing in at 45lbs in weight (20kg) to my local summits on the air location – G/SE-004 Butser Hill which is also a POTA location GB-0130. For a challenge we did a couple of laps of the hill, covering 12km and climbing to the top 4 times before setting up in the mist at the top. This time I used a resonant end-fed wire at around 45 degrees elevation into a tree. The weather was dry although cold and I applied the same system as before, operating for 40 minutes and achieving 16 QSOs before retreating to the handy coffee shop for a warm drink.

All in all the PRC-320 performed well, as expected it’s well suited to operation in the cold and wet outdoors and although it’s a heavy burden to carry it can do the business! The LSB modification worked perfectly. The next job will be to replace the original Tantalum capacitors with some modern equivalents as it does drift off frequency a little during operation. You can read about this issue here.