Wireless Set No. 52 Canadian - Project

[Chris Suslowicz]

Originally Posted by David Dunlop

Congrats on the new switchboard, Chris.

Thanks I need to trace the switch paths and match that with the front panel markings. The odd part is that they appear to have used "inactive" switch terminals as anchor points, because the upper switches have three "OFF" positions and only a single "ON" marking.

Your switchboard (despite claiming to be a Mk.1) is later than, and different to both of mine. It also doesn't match the one that Guy (in Belgium) has got for his wireless truck. I'm convinced yours is (or was) an Air Ministry "special" that has been re-purposed before being sold off and gutted/rewired.

After a couple of days trying to figure out where that short black lead had originally come from in the switchboard wiring, I was about ready to set it aside and move on when I remembered I had just been looking at all the standard Switchboard, Charging No. 5C possibilities. This switchboard was actually a No. 5C Mk I, with two additional sets of Battery terminals, so I took a closer look at the two negative Terminal Posts.

Are they Battery terminals though? Starting at the top, you have:

*. *
12V+. Batt
BATT No.1. No.1
12V- CHARGE
* *

*
+
CHARGER
No.1
-
*

...and the equivalent terminals for BATTERY No.2, CHARGER No.2 and INTERIOR LIGHTING on the opposite side of the board.

I think the additional terminals were for the connection of an AC Mains powered trickle (or float) charger to maintain the batteries when not in use in the field and an AC supply was available. (To avoid the need to run the charging set(s), saving fuel and reducing noise, etc.)

From the back of the switchboard, the additional negative terminal on the right hand side was too far away from any negative terminal on the lower switch, that it could logically tie into. Likewise, the upper switch. On the left side, things were suddenly looking up big time. With the curve of the wire for engaging the new negative battery terminal, properly oriented on the terminal stud, the smaller end for wrapping around a switch terminal, was properly oriented for engaging a terminal on the left side of the lower switch, and just the right length to engage the same switch terminal as the standard negative battery terminal wire was connected to already.

The current school of thought for the creation of the Switchboard, Charging No. 5C Mk I Cdn is that it was developed to help solve the thirst for Amps that the 52- Set and 19-Set HP had, in comparison to the basic 19-Set.

I'll (politely) disagree on that. The Switchboard 5C that Guy has appears to have the same stores code (with CAN/BR/ inserted because it's Canadian manufactured), and was issued with the WS19 Truck & Ground Station as well as the WS52 - it's the same switchboard apart from the lettering changes (Vehicle Dynamo and Power Unit to Charger No.1 and Charger No.2).

I think that change was made for the WS 52 ground station which was supplied with two charging sets. (Some WW2 vehicles carried a pair because they had multiple wireless sets, e.g. command vehicles.)

The easiest way to do that is to connect a second set of wireless batteries in parallel with the original set of batteries. This preserves the critical 12 Volts DC in the system for providing the required Low Tension feed to the wireless set. The big gain, however, is that instead of say just 175 Amp Hours from the original set of wireless batteries, the available Amperage doubles from 175 to 350. The higher the available amperage, the longer the wireless set can run before the batteries need recharging. What I am unsure of at this point, however, is how lone would it take for the standard 300 Watt Chorehorse to fully recharge two sets of wireless batteries connected in parallel, and could it handle the load of doing so easily?

The WS19 was supplied with either 6 Volt 85 Amp Hour accumulators (in pairs) and a power lead with Niphan plugs that would connect them in series and to the set supply unit, or 6 volt 100/125 Amp Hour ones (with butterfly nut terminals) - Command vehicles and tanks could get 170 AH batteries (again, 6-volt units).

The WS52 (I think) got 6-volt 200 Amp Hour batteries, and a Chore Horse could recharge those in 10 hours, so not a problem - but you would need two Chore Horses to bring everything back from "flat".

"Front Line" (static) units would not have charging sets as they would give their position away, so freshly charged batteries would be delivered along with rations and ammunition on a regular basis and the discharged batteries returned to a central recharging station (with 1260 Watt (or larger) charging sets and dedicated maintenance crews).

Best regards,
Chris. (G8KGS)