Author Topic: Grey 746 with a lock  (Read 2759 times)

Offline gpo706

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Re: Grey 746 with a lock
« Reply #15 on: July 30, 2011, 08:58:35 PM »
Interesting find on the bay which refers to the lock, says its Ministry of Defence modification -

"...these were factory modified by DFM for the UK Ministry of Defence and have a neat chrome plated keyswitch on the left hand side of the base. The key comes out in both positions so we guess it is used to acticvate or deactivate the phone. "

« Last Edit: July 30, 2011, 09:00:38 PM by gpo706 »
"now this should take five minutes, where's me screwdriver went now..?"

Offline gpo706

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Re: Grey 746 with a lock
« Reply #16 on: December 05, 2011, 11:12:22 AM »
I finally managed to get the key operative, I figured it was a simple switch so I shorted out the line - result - line cut off but when the key is in off position, the line was engaged on my PBX, ie off hook.

Slept on it and then thought why not just short the RX or TX on the handset?

So I shorted the RX, terminals 1 & 2, and that works perfectly, you can still dial out and transmit  but you cant hear anything.

Managed to break the dial surround and the blanking plate lugs which I had put a "on/off" bell switch in, so the switch was transplanted into a 746 topaz yellow and I will be glueing a grey blank on it, luckily the actual case didn't fragment so still have the U-shaped moueshole for the key.

I have never managed to break so much plastic with any other phone, its was a bloody nightmare trying to get the front, dial and the mousehole key lined up.

Never again, once its back together that's it done!

"now this should take five minutes, where's me screwdriver went now..?"

Offline Wallphone

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Re: Grey 746 with a lock
« Reply #17 on: December 05, 2011, 11:34:40 AM »
So I shorted the RX, terminals 1 & 2, and that works perfectly, you can still dial out and transmit  but you cant hear anything.
Is that so a person can yell for HELP! ?  :D
I thought that the key was to put the dial into a mode where only certain digits could be dialed.
Doug Pav

Offline GG

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Re: Grey 746 with a lock
« Reply #18 on: December 06, 2011, 04:33:49 AM »


Similar phones were used in Australia and Japan, with locks and keys, usually to short the dial pulse contacts entirely, the purpose of which being to prevent people making billable calls.  If BT wanted to enable the dial selectively for calling 999, and could use a payphone dial for that purpose, that would be an enhancement.


Offline Wallphone

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Re: Grey 746 with a lock
« Reply #19 on: December 06, 2011, 07:50:58 AM »
Scot, Did the first phone (746) have a #28 dial in it like Bob F. talked about in reply #7? On the second phone (pushbutton), did the manual say what the key was used for?
Doug Pav

Offline gpo706

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Re: Grey 746 with a lock
« Reply #20 on: December 06, 2011, 08:17:14 PM »
The second phone pic was for illustration only, I didn't buy it.

The dial looks standard for a 746, not a payphone variant.
"now this should take five minutes, where's me screwdriver went now..?"

Offline GG

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Re: Grey 746 with a lock
« Reply #21 on: December 06, 2011, 09:24:54 PM »


But where's the proof, aside from the seller's assertion, that the Tribune with key lock really was an MOD variation?  Judging from the number of red phones that are advertised as having been used for super-secret hot line conversations, I have to be somewhat skeptical.