Ericsson PA System - Help Me Identify Please - UK Vintage Radio Repair and Restoration Discussion Forum

JulianKoster · 11th Sep 2015, 6:22 pm

Dear All,

This is my very first post on this forum, a quick greeting from the Netherlands! I will immediately start off with a question. I have recently managed to save an old Public Announcement system from being thrown in the garbage. It was placed in an old school that was going to be demolished, I simply cut the wires and boxed it without looking for any manuals/technical sheets (if there were any to begin with...).

Now my question to all you tech-savvy masterminds is; does any of you recognize this Ericsson PA system so I can start finding out how to make it function again?

All I've found so far is that it is an Ericsson, with the number;

10539_4=3 9.66 on the bottom, could not figure out what it means exactly but maybe someone can shed some light on it?

Unfortunately the "phone" that was attached to it has been cut off, as well as the power cord, however the problems probably won't stop there.

I would highly appreciate any push in the right direction of finding out more about this awesome piece of technology!

paulsherwin · 11th Sep 2015, 7:25 pm

It appears to be the school's branch telephone exchange (PABX). The cradle on the left would be for a telephone handset.

OscarFoxtrot · 11th Sep 2015, 8:33 pm

I don't think it is a PABX.

There's no dial, and the bottom right knob appears more like a volume control.

I think it's an intercom unit that had the ability to call each classroom, or all-call, and possibly switch each classroom to either a 'programme' or an 'announcement' bus. These were commonly used in the USA.

Basically a 70 or 100 volt line PA amp for announcements, and a second smaller amp used in reverse for intercom listening. 3 or 4 wires to each speaker and the speakers possibly had a relay in to switch them on/off to the audio bus.

Stromberg Carlson advert
https://www.etsy.com/uk/listing/2150...age?ref=market

Modern Bogen equipment
https://www.bogen-paging.com/catalog-product-pi35a.aspx

Herald1360 · 11th Sep 2015, 8:35 pm

9-66 is probably Sept 66 date.

Unless there's an amplifier in there somwhere, it's unlikely to have any direct use in a PA system.

vosperd · 15th Sep 2015, 4:46 pm

It could be the selector for a PA system with a remote amplifier.
When I moved into a modern school in 1956 we had a speaker and a slave clock in each classroom, I think that system was a Gents. I was convinced it was a 2-way system as the teachers had an uncanny knack of getting to the source of any disruption pretty quick.
Don m5aky

JulianKoster · 17th Sep 2015, 1:29 pm

Thank you all for your input; from what I know is that every classroom had it's own "phone" to communicate with the central system, with speakers being located around the school. Was able to retrieve a telephone unit but not a speaker.

11th Sep 2015, 6:22 pm	#1
JulianKoster Retired Dormant Member Join Date: Sep 2015 Location: Gouda, Netherlands Posts: 2	Ericsson PA System - Help Me Identify Please Dear All, This is my very first post on this forum, a quick greeting from the Netherlands! I will immediately start off with a question. I have recently managed to save an old Public Announcement system from being thrown in the garbage. It was placed in an old school that was going to be demolished, I simply cut the wires and boxed it without looking for any manuals/technical sheets (if there were any to begin with...). Now my question to all you tech-savvy masterminds is; does any of you recognize this Ericsson PA system so I can start finding out how to make it function again? All I've found so far is that it is an Ericsson, with the number; 10539_4=3 9.66 on the bottom, could not figure out what it means exactly but maybe someone can shed some light on it? Unfortunately the "phone" that was attached to it has been cut off, as well as the power cord, however the problems probably won't stop there. I would highly appreciate any push in the right direction of finding out more about this awesome piece of technology! Attached Thumbnails

11th Sep 2015, 7:25 pm	#2
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 28,012	Re: Ericsson PA System - Help Me Identify Please It appears to be the school's branch telephone exchange (PABX). The cradle on the left would be for a telephone handset.

11th Sep 2015, 8:33 pm	#3
OscarFoxtrot Heptode Join Date: Apr 2011 Location: Edinburgh, UK. Posts: 805	Re: Ericsson PA System - Help Me Identify Please I don't think it is a PABX. There's no dial, and the bottom right knob appears more like a volume control. I think it's an intercom unit that had the ability to call each classroom, or all-call, and possibly switch each classroom to either a 'programme' or an 'announcement' bus. These were commonly used in the USA. Basically a 70 or 100 volt line PA amp for announcements, and a second smaller amp used in reverse for intercom listening. 3 or 4 wires to each speaker and the speakers possibly had a relay in to switch them on/off to the audio bus. Stromberg Carlson advert https://www.etsy.com/uk/listing/2150...age?ref=market Modern Bogen equipment https://www.bogen-paging.com/catalog-product-pi35a.aspx

11th Sep 2015, 8:35 pm	#4
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,536	Re: Ericsson PA System - Help Me Identify Please 9-66 is probably Sept 66 date. Unless there's an amplifier in there somwhere, it's unlikely to have any direct use in a PA system. __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

15th Sep 2015, 4:46 pm	#5
vosperd Hexode Join Date: Oct 2007 Location: Bristol, UK. Posts: 446	Re: Ericsson PA System - Help Me Identify Please It could be the selector for a PA system with a remote amplifier. When I moved into a modern school in 1956 we had a speaker and a slave clock in each classroom, I think that system was a Gents. I was convinced it was a 2-way system as the teachers had an uncanny knack of getting to the source of any disruption pretty quick. Don m5aky

17th Sep 2015, 1:29 pm	#6
JulianKoster Retired Dormant Member Join Date: Sep 2015 Location: Gouda, Netherlands Posts: 2	Re: Ericsson PA System - Help Me Identify Please Thank you all for your input; from what I know is that every classroom had it's own "phone" to communicate with the central system, with speakers being located around the school. Was able to retrieve a telephone unit but not a speaker.