Identification on this Speaker please? - UK Vintage Radio Repair and Restoration Discussion Forum

electronicskip · 20th Aug 2017, 1:16 pm

Someone has given me a small Speaker that came out of an old house recently , there is no identification and nothing to suggest power output.

Does anyone recognise it?

Edward Huggins · 20th Aug 2017, 1:48 pm

Welcome and thanks for your query. Speakers don't have any such thing as "power output", but they do have handling power. This one looks pre-war and without seeing the internals it probably handles about 3 watts of input power. Also we cannot assess the input impedance, it might be 3 ohms.

paulsherwin · 20th Aug 2017, 2:13 pm

A quick and dirty way of assessing the impedence is to measure the DC resistance and increase it by half.

Radio Wrangler · 20th Aug 2017, 2:42 pm

A photo of the drive unit inside that cabinet might help.

David

electronicskip · 20th Aug 2017, 3:34 pm

Its taken me about 40mins of gentle coaxing to get the back off the unit as it was screwed down plus, I don't think its ever been off by the look of it.

Here is what I found, but I'm still none the wiser due to having little knowledge of old audio equipment age wise or make.

AC/HL · 20th Aug 2017, 3:51 pm

Is/was there a hole in the centre of the front, the photo isn't clear? I'd guess the original moving iron speaker was replaced by the Rola at some time, at a cost of 24 shillings.

paulsherwin · 20th Aug 2017, 3:55 pm

The speaker appears to be a typical 1930s permanent magnet type.

I don't think the cabinet is as old as Bill suggests. I would guess it's a man-in-a-shed job. Extension speakers were popular home woodworking projects from the 30s through to the 60s. An uncle of mine built a floor standing corner enclosure with a frosted glass top and a bulb underneath - I still have it in the loft. These were mostly used in dining rooms, connected to a radio in the lounge.

electronicskip · 20th Aug 2017, 4:12 pm

Quote:

Originally Posted by AC/HL

Is/was there a hole in the centre of the front, the photo isn't clear?

I can't see a hole to be honest no.

I'm going it try it later and see if there is any life in the old beast.

ms660 · 20th Aug 2017, 4:37 pm

Looks like 1938 when the speaker itself came out:

http://www.americanradiohistory.com/...search=%22rola type 8z%22

Lawrence.

20th Aug 2017, 1:16 pm	#1
electronicskip Nonode Join Date: Oct 2010 Location: Gloucester, Glos. UK. Posts: 2,150	Identification on this Speaker please? Someone has given me a small Speaker that came out of an old house recently , there is no identification and nothing to suggest power output. Does anyone recognise it? Attached Thumbnails

20th Aug 2017, 1:48 pm	#2
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,331	Re: Identification on this Speaker please? Welcome and thanks for your query. Speakers don't have any such thing as "power output", but they do have handling power. This one looks pre-war and without seeing the internals it probably handles about 3 watts of input power. Also we cannot assess the input impedance, it might be 3 ohms. __________________ Edward.

20th Aug 2017, 2:13 pm	#3
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,947	Re: Identification on this Speaker please? A quick and dirty way of assessing the impedence is to measure the DC resistance and increase it by half.

20th Aug 2017, 2:42 pm	#4
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,879	Re: Identification on this Speaker please? A photo of the drive unit inside that cabinet might help. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

20th Aug 2017, 3:34 pm	#5
electronicskip Nonode Join Date: Oct 2010 Location: Gloucester, Glos. UK. Posts: 2,150	Re: Identification on this Speaker please? Its taken me about 40mins of gentle coaxing to get the back off the unit as it was screwed down plus, I don't think its ever been off by the look of it. Here is what I found, but I'm still none the wiser due to having little knowledge of old audio equipment age wise or make. Attached Thumbnails

20th Aug 2017, 3:51 pm	#6
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: Identification on this Speaker please? Is/was there a hole in the centre of the front, the photo isn't clear? I'd guess the original moving iron speaker was replaced by the Rola at some time, at a cost of 24 shillings.

20th Aug 2017, 3:55 pm	#7
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,947	Re: Identification on this Speaker please? The speaker appears to be a typical 1930s permanent magnet type. I don't think the cabinet is as old as Bill suggests. I would guess it's a man-in-a-shed job. Extension speakers were popular home woodworking projects from the 30s through to the 60s. An uncle of mine built a floor standing corner enclosure with a frosted glass top and a bulb underneath - I still have it in the loft. These were mostly used in dining rooms, connected to a radio in the lounge.

20th Aug 2017, 4:37 pm	#9
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Identification on this Speaker please? Looks like 1938 when the speaker itself came out: http://www.americanradiohistory.com/...search=%22rola type 8z%22 Lawrence.