Wireless Set No. 52 Canadian - Project

[David Dunlop]

Well, a final close inspection of this Receiver chassis shows it to be in very good condition with only two wiring issues turning up and one missing valve shield cap. Valves not yet tested, however.

I have a wire on the ground side of the speaker that has broken free from the Meter Switch. This should be a simple resolder job once the correct terminal to attach it to on the switch has been confirmed.

On a more serious note, the middle terminal wafer on the Mode of Operation switch has been shattered. These switches were designed to be taken apart for situations such as this. Just need to determine best repair/replacement option. Dealing with the middle wafer only involves 6 soldered terminals to deal with. To replace the entire switch means dealing with 23 soldered terminals.

David

[David Dunlop]

The power socket on the back of the 52-Set receiver has 7 clips in it.

Can anyone post a photo of the corresponding plug on the Remote Receiver Supply cable? I am guessing there are fewer than 7 tabs on the cable plug since when the receiver is in remote mode, the transmitter and main set PSU connections would be irrelevant.

I am trying to sort out the various circuit diagrams this morning, when compared with reality, and I don’t think the coffee is kicking in yet.

David

[Chris Suslowicz]

I think you need +12V, +250V, Aerial and Earth/Chassis.

The remote receiver cable has an aerial terminal on the back of the plug and a cable to the AC/vibrator supply unit.

(Not that I've ever seen one in real life.)

Chris.

[David Dunlop]

That was my thought as well, Chris.

The Remote Supply output is through a three tab Jones plug setup and I was thinking the +12 and the +150 (lower HT value) were two likely candidates, along with a ground circuit.

When I compare the tab layout on the Supply Cable I have, two tabs indeed match up with the +12 and +150 clips on the receiver socket. However, the third tab on the cable plug goes into a dead space with no designated clip on the receiver socket.

No sign of Bubba being at the receiver, but maybe he was playing with the cable at some point. Adding to the puzzle, there are no labels on the cable plug tabs to ID them.

David

[Chris Suslowicz]

Maybe you don't have a remote receiver?

I have some stripped-out sockets downstairs and will have a look later tonight - they have decals with the connection details on them.

Chris.

[David Dunlop]

Thanks, Chris.

When I read through the manual, I was left with the impression the Main Set Receiver and the Remote Receiver were virtually interchangeable. The only difference was the wording on their respective data plates. Wouldn’t be the first time I have been confused, however.

David

[David Dunlop]

Well, another 45 minutes of research and I think I have it sorted out.

As Chris stated, one needs +12 and the lower HT voltage (+150) feed, along with a suitable Ground/Earth connection to make the Remote Supply and the 52-Set Receiver play nice with each other. So basically three connections, either end.

The Supply Connector Cable assembly does, indeed have three tabs inside it at the receiver end box. Two feed the required plus voltages to the set. The third one goes nowhere at the receiver. Turns out this is absolutely correct for the 52-Set. Ground/Earth between the 52-Set Receiver and Remote Supply is achieved by the long burled locking screw that secures the Connector Plug to the Receiver Socket.

The mystery third tab in the Connector Cable Plug, going nowhere, is also correct. It feeds to the Aerial Terminal on the end of the Connector Cable Plug. Turns out the Connector Cable (CMC 106-560) was developed by Marconi for the Wireless Set No. 9 Mk I Cdn for it’s remote receiver. In that particular No. 9 Set Remote Receiver, that Aerial Terminal tab in the Connector Cable is functional. Totally redundant for the 52-Set Remote Receiver, but more efficient for Marconi not to bother changing the design.

Apparently there is a colour difference, however. If the cover on the back of the Remote Supply Connector Cable plug is wrinkle green, the cable was built for the WS No. 9 Mk I. If it is No. 2 Brown, the cable was part of 52-Set Cdn production.

As long as the Connector Cable is a CMC 106-560, it is good for either wireless set.

David

[Chris Suslowicz]

Originally Posted by David Dunlop

On a more serious note, the middle terminal wafer on the Mode of Operation switch has been shattered. These switches were designed to be taken apart for situations such as this. Just need to determine best repair/replacement option. Dealing with the middle wafer only involves 6 soldered terminals to deal with. To replace the entire switch means dealing with 23 soldered terminals.

David

The 'Second to Fourth Echelon' EMER (F 524) has the wiring diagrams for the switch wafers, complete with wire colour codes. This may well be helpful.

Chris.
(I also note that it has a section on "Dismantling the Flick mechanism" (though not how to reassemble it from the resulting heap of small parts). I may have to write another article at some point.)