LRDG Wireless set up

[Mike Cecil]

Charlie,

As far as I'm aware, only the top view of the battery will tell you the voltage (by the number of cells visible).

Mike

[Charlie Down]

Ok. Found these LRDG Documents, I think originally marked 'TOP SECRET'.
So they used 2 standard 6 volt truck batteries, one from the truck and one mounted next to it on the side step. They were used in series for wireless operation and in parallel for charging, via a 'special series Parallel switch'. The trucks generator charged the batteries and if on road watch for several days batteries were swapped with batteries from another truck. This required no chore horse charging set.
The second document shows the maintenance procedure for the wireless equipment in the field.
So does that mean the panel only needed one knife switch, and they used a standard 4 switch panel and removed the other 3 knife switches, or a 2 knife switch panel with a knife switch removed? The 2 positions of the switch would be series and parallel.
Looking at the attached compilation of switch panels I think I'm leaning towards a 2 switch panel with one switch removed.
Also what is involved with setting a truck up to be wireless suppressed?
Could the photo at the start be another truck waiting to swap batteries, based on this new information?

[Lynn Eades]

There is quite a lot involved in radio suppression on a veh. Lots of earth / bond straps every where. A suppressor on the generator and the distributor, some shielded wiring (generator to regulator) etc. and filter boxes. Have a look at Jeeps, and Dodges. The American manuals give pretty good info on this sort of thing, with lots of photos. Most American production rolled out of the factories with it all done from around 1941. The thing is that its not just the veh. with the radio in it, It's all of the vehicles in proximity that cause a problem.

[Ron Pier]

Yes this is like the earth grounding kit I fitted to my Jeep many years ago, just to dress it up. Along with all the required filters and suppression parts that Lynn mentioned.
https://www.mvspares.com/WWII-JEEP-P...iijeep-418.htm

In line suppressors were fitted in the HT leads of motorcycles which was detrimental to their use, as magnetos don't work as well through a suppressor.

Ron

[Charlie Down]

So, having thought about it and looked at other documents and photos, my current conclusion is that the LRDG used the same set up throughout the Desert campaign on all their trucks-Chevrolet WA, 1533X2 and Ford F30s. They used a WS11 High Power unit with Windom centre feed or sometimes end feed aerials on 16' duraluminium poles stowed on the trucks, and the 4' rod aerials for local (100 mile range) communication between Patrols. The power supply was fed through a 'Special' series/parallel switch for trickle charging/wireless use, from 2 standard 6 Volt batteries, one the truck battery, the other a 'booster' battery to provide the necessary 12 volts with the truck battery for the wireless. The 'booster' was mounted on the side step in front of the driver. During long periods of stationary Patrol, Road Watch, the Patrol would either take a chore horse to recharge the batteries or swap batteries with the other trucks in the Patrol. Very high levels of training were given to the signallers, this being the primary reason for the successful long range communication, not the limitations of the wireless. Very high levels of maintenance were given to the wireless and accessories throughout the Patrol. No information is given on what periods of the campaign chore horses are used, but it seems they were more common later on. I suspect that all the Chevrolet 1533X2 trucks, and most likely the CMP Ford F30s were fitted with wireless suppression fittings as standard, but on the WA's not so sure. Most likely the ones from the Egyptian Army would be suppressed, which would therefore be primary choice for wireless trucks, but not the ones sourced from the civilian dealership in Alexandria.

I've put a drawing together of the series/parallel switch based on the photos (not dimensionally accurate and most likely wrong with some details, but its something to work on!), and on the assumption its the same switch, but on the Chevrolet WAs it had a protective edge due to its external mounting on the outside of the rear body, but on the Chevrolet 1533X2 no protection was needed because it was mounted in the cab behind the Drivers seat. No photos found yet of its location on the Ford F30's, but its not externally mounted on the rear body, or in the cab, based on the limited number of photos showing those area of wireless trucks. It may be mounted in the plywood wireless compartment, or possibly in one of the tool boxes below the wireless compartment. Hopefully something will turn up.