Post Office 52A power supply - UK Vintage Radio Repair and Restoration Discussion Forum

ppppenguin · 12th Oct 2007, 10:14 pm

I have acquired one of these units. Looks like a solidly built unit in a wall mounted metal case. There's a transformer, finned metal rectifier bridge, 2x 2500uf caps and a chunky choke. There's also a 2nd transformer marked 6.5V, 6A which looks like it has been added after manufacture.

I'm guessing that the main supply is 50VDC for telephone kit. What were these units used for?

Sean Williams · 12th Oct 2007, 10:18 pm

http://web.ukonline.co.uk/freshwater/pugpo1.htm

This ought to tell you everything you need

Looks Fairly useful

Cheers
Sean

ppppenguin · 12th Oct 2007, 10:31 pm

Sean, thanks for the info.

AndiiT · 13th Oct 2007, 12:17 pm

Quote:

Originally Posted by ppppenguin

.....I'm guessing that the main supply is 50VDC for telephone kit. What were these units used for?

Hi,
The information on Bob Freshwaters site is, as you have probably already realised, relating to a number of different power supplies and their installation/uses.
Looking through that info the 52A power supply was designed for use with the 2/ and 4/ series of PMBX switchboards of the type shown in the following links -

http://www.britishtelephones.com/pmbx2.htm
http://www.britishtelephones.com/pmbx4.htm

Regards
Andrew

12th Oct 2007, 10:14 pm	#1
ppppenguin Retired Dormant Member Join Date: Dec 2003 Location: North London, UK. Posts: 6,168	Post Office 52A power supply I have acquired one of these units. Looks like a solidly built unit in a wall mounted metal case. There's a transformer, finned metal rectifier bridge, 2x 2500uf caps and a chunky choke. There's also a 2nd transformer marked 6.5V, 6A which looks like it has been added after manufacture. I'm guessing that the main supply is 50VDC for telephone kit. What were these units used for?

12th Oct 2007, 10:18 pm	#2
Sean Williams Dekatron Join Date: Feb 2005 Location: St.Ippolyts, Hitchin, Hertfordshire QRA IO91UW Posts: 3,517	Re: Post Office 52A power supply http://web.ukonline.co.uk/freshwater/pugpo1.htm This ought to tell you everything you need Looks Fairly useful Cheers Sean __________________ Engineers make things work and have spare bits when finished

12th Oct 2007, 10:31 pm	#3
ppppenguin Retired Dormant Member Join Date: Dec 2003 Location: North London, UK. Posts: 6,168	Re: Post Office 52A power supply Sean, thanks for the info.