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 Attaching a modern plug to a PMG 400 series phone.
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 Return to top of page · Post #: 1 · Written at 9:34:06 PM on 12 May 2012.
Fraggle's Gravatar
 Location: Allenstown, QLD
 Member since 12 May 2012
 Member #: 1146
 Postcount: 7

Hi Guys,

I recently acquired a PMG 400 series desktop phone, unfortunately someone has cut the plug off the end. Stripping back the black outer covering on whats left of the cord I have a red, a blue and a white wire.

My question is does anyone know how to wire this into a standard RJ12 socket so I can see if the phone still works.

Thanks.


 
 Return to top of page · Post #: 2 · Written at 11:01:34 PM on 12 May 2012.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 5511

Mine has a green wire instead of blue and I have the green and white set up as a pair. It is a guess but the blue and white may be the way to go for you.

You will not get these cables to terminate in an RJ plug though as the strands are very pliable and interwoven with cotton. You'd be better off using a standard Telecom plug and then purchasing a Telecom-RJ adaptor from Jaycar or Dick Smith.


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 3 · Written at 2:08:45 AM on 13 May 2012.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 5263

Blue and white sound correct.

That tinsel type wire is very difficult to deal with and is designed to be terminated via crimped-on connectors. I agree with Brad about using a 605 plug and 610 to RJ adapter.

http://www.jaycar.com.au/productView.asp?ID=PP1400&form=CAT2&SUBCATID=1047#6.

http://dicksmith.com.au/product/F2172/std-socket-to-rj12-45-adaptor-610-rj12-plug-rj45-rs2.


 
 Return to top of page · Post #: 4 · Written at 3:05:17 PM on 13 May 2012.
Fraggle's Gravatar
 Location: Allenstown, QLD
 Member since 12 May 2012
 Member #: 1146
 Postcount: 7

Thanks guys, the blue and the white were the winners.

I have a dial tone, but no ringer and the dial needs adjusting. These are jobs to tackle when I get back from work next week.

If you have any ideas or webpages you could point me to for these next two problems it would be greatly appreciated.

On a side note if you are connecting the phone to a RJ12 plug its pins 4+5 and on a RJ45 plug its pins 5+6 (found this on the whirlpool forums.)

Thanks again.


 
 Return to top of page · Post #: 5 · Written at 12:18:21 PM on 21 May 2012.
Duconbuster's Gravatar
 Location: Melbourne, VIC
 Member since 7 August 2009
 Member #: 526
 Postcount: 111

Hiya Fraggle, to make the phone ring you need to link terminals 1&2 in the phone. The phone was originally wired to work in a socket "610" which contained a strap enabling the internal bell or wiring to ext bell. If after you you do this a CND phone on same line or socket will no longer show incoming call numbers then add a 1k resistor in place of link 11-12. These old phone bells sound fantastic, enjoy
Paul


 
 Return to top of page · Post #: 6 · Written at 1:20:29 PM on 21 May 2012.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 5263

These old phone bells sound fantastic

Individually, I agree, but an office full of them going on and on could send you crazy. I was so glad when the 800 series arrived at work with the ability to silence the bells.


 
 Return to top of page · Post #: 7 · Written at 3:40:36 PM on 26 October 2012.
Fraggle's Gravatar
 Location: Allenstown, QLD
 Member since 12 May 2012
 Member #: 1146
 Postcount: 7

Sorry about taking so long to get back to you guys.

Events out in the real world sidelined this project for a while.

Thanks Duconbuster the bell now rings loud and clear.

I ended up changing out the old phone cable for a new black cable and attaching it straight to the screw board inside the phone. I was having too much trouble with that old piece of cable.

The only problem I have now is that when talking on it the sound coming from the reciever is very quite and the person you are talking to can also only just hear you.

Thanks again guys for the help so far, any ideas would be appreciated.


 
 Return to top of page · Post #: 8 · Written at 9:32:59 PM on 26 October 2012.
MonochromeTV's avatar
 Location: Melbourne, VIC
 Member since 20 September 2011
 Member #: 1009
 Postcount: 1043

Hi,

Is your phone a APO or BPO 400 series? Circuit wise, they are identical. Construction wise they are different. The APO versions are made in Australia by AWA or STC. All their circuitry and mechanisms are built into the base, and they often have round vents in sides. The BPO versions have their circuitry and mechanisms mounted in to the casing and the base has a bakelite blanking piece. As for line-cord, the APO terminal 1 inside the phone is the white wire, 2, red or green* and 3 blue or red*. The terminals in the plug and socket are 2, 3 & 6 respectively with 2 & 3 (socket only) linked for the bell. (The bell link inside both types of phones is 1 & 2) The BPO version is as follows: 1 white, 2 red or green* and 9 blue or red* The terminals on the plug and socket are the same as above. The phone line into the socket is: 2, white & blue, 6. (* = the older style of hard wired cords). The line cord wired incorrectly is a cause weak sound but also can be caused by faulty earpiece or microphone.

Cheers.

B19 400 APO telephone circuit diagram
B20 400 APO telephone circuit diagram


 
 Return to top of page · Post #: 9 · Written at 11:01:43 PM on 26 October 2012.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 5263

As above, could be a few things, including the mike.

Carbon granule microphones suffered from granule compaction which both attenuated the voice and also created a hissing sound on the line caused by the granules "frying".

Both symptoms caused the party at the other end to say: "What? Speak up! We have a bad line."

A good hard tap of the mike was often needed to loosen them up again.


 
 Return to top of page · Post #: 10 · Written at 12:24:13 PM on 27 October 2012.
Fraggle's Gravatar
 Location: Allenstown, QLD
 Member since 12 May 2012
 Member #: 1146
 Postcount: 7

The phone is a BPO series 400.

The diagram inside the base plate is the same as the second one minus the right diagram showing the extension bell wiring.

Got the sound levels right. I had the 1 & 2 wires around the wrong way in relation to how they fell in the RJ12 plug.

It works beautifully now.

Thanks for all your help guys.


 
 Return to top of page · Post #: 11 · Written at 9:58:32 PM on 21 January 2017.
Alexschipperen's Gravatar
 Location: Chewton, VIC
 Member since 21 January 2017
 Member #: 2049
 Postcount: 1

Hello. I was given a PMG 400 and it is fitted with a modern plug. I can make and receive calls except that the bell doesn't ring. The volume in the earpiece is very low. It has 3 wires connected: yellow in 1 (bridged to 2) green in 3 and red in 11. Black has been cut short and is not connected. Any help appreciated!

Alex, Chewton


 
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