Clansman VHF Radio Trials at Beachy Head

Preparations at Beachy Head Radio Site

Members of the BHRS group had arranged to meet at the site from 1230 with the intention being to make for distant sites by vehicle and establishing a net on VHF. The primary frequency to be used was 51.60MHz FM..

The Lister driven generator started easily and we quickly set about the task of raising the Tennamast complete with Ten element 2 metre beam and Clansman Dipole for HF. The 2m system was to be used for talkback with the main VHF aerial being an elevated VHF (Pineapple) on the Racal mast fitted to my Land Rover FFR. HF communications from the Clansman RT320 (PRC320) were also available as a back-up and if we had time for further tests. The main VHF set to be used at BHRS was an old favourite the RT353 covering 30-77 MHz.  As the RT353 can run up to 70W RF, which could be useful under difficult conditions, 24V power at 10 Amps would be provided by a Clansman PSU 50A weighing 40kg! This is the supply that is normally used with the RT322 High Power HF station and can provide 24V at a continuous load of 50 Amps.

BHRS Racal Mast carrying EVHF Antenna on FFR.  Dr Jon and Baxter at doorway of operating hut

With the basic station tasks completed, it was now time for food and refreshment, those departing to distant and high places would need fortification against the cold! Tom M6ONX volunteered to be duty Chef and a round of Sausage, Bacon & Egg sandwiches were quickly prepared and consumed even more rapidly. The Eggs were especially good being freshly laid by Tom’s Chickens. Apparently the Chickens’ Egg production is on a go-slow at the moment and Tom is hoping to appease them by building a new Chicken Coup. The results are awaited with great anticipation!  Suitably fed all that was required now was for the various teams and individuals to depart to their chosen destination and set up their station.

With the theme for the day being the use of Clansman equipment RT351 portables were to be used at all of the remote stations. The RT351 or PRC351 as it is better known by the British Army covers 30-76.975MHz with 4 Watts FM output. On this occasion the PRC351 sets would just be used with either their short flexible Patrol Whip or Titanium Battle-Whip. Andy M6GND departed for Firle Beacon with Richard M6EYO and his brother Dr Jon M0JAO heading for Crowborough.

Dr Jon M0JAO with RT351 in the back of his Series One Land Rover.

Dave G4XXM went mobile heading East and kept in contact with BHRS over the whole route even when in the RF shadow of Beachy Head. Whilst mobile Dave was using a quarter wave resonant on 4m, hardly ideal but working well on 6m! He arrived at Pevensey Levels near Rickney and was joined by Tom M6ONX. Dave was the first outstation to establish communications with G1KAR/P signals being fully quieting in both directions to BHRS.

Andy M6GND was the next station to check-in from the Western slopes of Firle Beacon with an excellent signal.  The RT353 being used at BHRS for G1KAR/P was initially set to the 15W power position but Andy could easily read our signals at 1 Watt RF output. Initially Andy was using the short Patrol Whip which was perfectly adequate but when he swapped over to the standard 1.2m Titanium Battle Whip his signal strength improved noticeably. Jon was the next to call-in but his signals were quite noisy. At the time he was using the Battle Whip with his RT351 in the back of his Series One. Fortunately Richard had brought his EVHF antenna which he raised just above the vehicle. When connected to the Clansman 351 the improvement in received signal at BHRS was considerable. We now had communications with Dave at Rickney, Andy at Firle Beacon and Jon at Kingstanding (Crowborough). BHRS could easily work all stations with “OK” signals. Andy could contact Jon and Dave but there was no direct path from Rickney to Kinstanding. This was probably due to Windmill Hill at Herstmonceux disrupting the direct path.

I can hear knowledgeable readers say that “they have done nothing new” and that going to high ground is almost certainly going to provide communications over the ranges established.

This is entirely true, but we were using equipment that is between 35-40 years old and under field conditions with vertical whip aerials.  Many of us are perhaps too used to using SSB into beam aerials and Repeaters to achieve long ranges on VHF/UHF. The back to basics approach can often teach us some useful lessons. Carrying a basic PRC351 weighing 9.3kg to a hilltop is also good healthy exercise!

The main object for the day was to have fun and check the Clansman RT351 range capabilities during the process. We intend to continue with such trials using  MF and other bands as required to establish contact from difficult locations. There has also been suggestions to practice message handling using many different modes and frequencies. This is very much in tune with the spirit of the Amateur Licence and “Operator Training”

Clansman RT352 (PRC352) RT351 Plus 20W RF Amplifier This must be used with the Ground Spike Antenna (GSA) when on High Power. 

New members are welcome to join us particularly those that have an interest in Military radio, Military Vehicles, Clansman, Larkspur or Data modes such as PSK31 and JT64 etc. Perhaps you just have an interest in radio, and like us, wish to learn more?

The contact form on this site can be used for further information.

Barry G8DXU