GPO 332 conversion to plug and socket. - UK Vintage Radio Repair and Restoration Discussion Forum

Martyn K · 25th Mar 2021, 9:29 pm

Hi, I hope you can give me some advice. I HAVE NO EXPERIENCE AT ALL, but doing a Lockdown project with my son.

We are trying to get a GPO 332L working on a BT line.

I am NOT trying a Ringtone Conversion

I am trying to get it working on the old Pulse signal

So far we can:-

Ring in to the 332L from my mobile phone

The bells ring on the 332L

I can hear the person on the 332L speak to me clearly

BUT:-

The person on the 332L cannot hear me at all

Additionally, when I connect/plug into my home phone socket with the 332L my internet goes OFF until I unplug it

I have NOT been able to ring out from the 332L yet

Possibly the Dial is not good? (12FBR 62/2)

My Line colours are the new ones so I have transposed as below

See LIST below for colours and connections made

My Handset is complete – No. 164
New diaphragm fitted just in case
I am using the existing cord

Green – T3
White – T4
Red – T5

332L LINE cord colours
OLD-NEW BT Plug cord colours

Red-Yellow-B-T9
Blue-Green-Ringer-T11
White-Black-A-T1

Green-Red-spare-not used

Terminals Linked
T1 + T2
T8 + T9
T10 + T11 + T12

russell_w_b · 26th Mar 2021, 5:37 pm

Hi Martyn, and welcome to the forum.

You appear to have the telephone's own capacitor linked in and you shouldn't need that if you're plugging into a line-jack unit.

Could you connect your lead to your telephone as per the attached diagram? My diagram shows the 'traditional' colours that come with a BT standard plug and lead. The numbers on the BT plug read left to right as you look down on the contact side with the lead towards you and the plug-end away from you. Don't worry about a resistor between terminals 11 and 12 for now - a link will be fine.

Dave Moll · 26th Mar 2021, 7:47 pm

Although, as Russell says, you need to disconnect the internal capacitor if you are using the ringing wire from the master socket, I wouldn't expect this to cause the problems you describe, so you may still have a problem after doing so.

russell_w_b · 26th Mar 2021, 8:00 pm

Quote:

Originally Posted by Dave Moll

I wouldn't expect this to cause the problems you describe, so you may still have a problem after doing so.

I wouldn't either, Dave, but I thought better to start from a 'clean' plug and socket conversion and take things from there. I run my 1968 Ericsson Dialog with the internal capacitor connected and in parallel with the one in the LJU and it works fine.

Dave Moll · 26th Mar 2021, 8:22 pm

Indeed!

25th Mar 2021, 9:29 pm	#1
Martyn K Diode Join Date: Mar 2021 Location: Belfast, Northern Ireland, UK. Posts: 1	GPO 332 conversion to plug and socket. Hi, I hope you can give me some advice. I HAVE NO EXPERIENCE AT ALL, but doing a Lockdown project with my son. We are trying to get a GPO 332L working on a BT line. I am NOT trying a Ringtone Conversion I am trying to get it working on the old Pulse signal So far we can:- Ring in to the 332L from my mobile phone The bells ring on the 332L I can hear the person on the 332L speak to me clearly BUT:- The person on the 332L cannot hear me at all Additionally, when I connect/plug into my home phone socket with the 332L my internet goes OFF until I unplug it I have NOT been able to ring out from the 332L yet Possibly the Dial is not good? (12FBR 62/2) My Line colours are the new ones so I have transposed as below See LIST below for colours and connections made My Handset is complete – No. 164 New diaphragm fitted just in case I am using the existing cord Green – T3 White – T4 Red – T5 332L LINE cord colours OLD-NEW BT Plug cord colours Red-Yellow-B-T9 Blue-Green-Ringer-T11 White-Black-A-T1 Green-Red-spare-not used Terminals Linked T1 + T2 T8 + T9 T10 + T11 + T12

26th Mar 2021, 5:37 pm	#2
russell_w_b Dekatron Join Date: Jul 2007 Location: Penrith, Cumbria, UK. Posts: 3,687	Re: GPO 332 conversion to plug and socket. Hi Martyn, and welcome to the forum. You appear to have the telephone's own capacitor linked in and you shouldn't need that if you're plugging into a line-jack unit. Could you connect your lead to your telephone as per the attached diagram? My diagram shows the 'traditional' colours that come with a BT standard plug and lead. The numbers on the BT plug read left to right as you look down on the contact side with the lead towards you and the plug-end away from you. Don't worry about a resistor between terminals 11 and 12 for now - a link will be fine. Attached Thumbnails __________________ Regds, Russell W. B. G4YLI.

26th Mar 2021, 7:47 pm	#3
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,127	Re: GPO 332 conversion to plug and socket. Although, as Russell says, you need to disconnect the internal capacitor if you are using the ringing wire from the master socket, I wouldn't expect this to cause the problems you describe, so you may still have a problem after doing so. __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)

26th Mar 2021, 8:22 pm	#5
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,127	Re: GPO 332 conversion to plug and socket. Indeed! __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)