Classic Rotary Phones Forum

Telephone Identification, Repair & Restoration => Telephone Component Identification => Topic started by: FABphones on July 01, 2018, 11:49:04 AM

Title: GPO fingerplate marked '50% Test'
Post by: FABphones on July 01, 2018, 11:49:04 AM
I was going through some of the joblot odds and ends this afternoon when I spotted a fingerplate that had received somewhat too much of a rub down. When I looked closer I saw written '50% Test'.

Does anyone know anything about this? It appears to be etched on so no amount of rubbing would remove it but it does look like someone has tried to rub it out.

Pic below.
Any info would be appreciated.
Thanks.
Title: Re: GPO fingerplate marked '50% Test'
Post by: tubaman on July 01, 2018, 01:00:09 PM
I don't have much detail but know that they were used on testers of some sort - probably for testing the extremes of the make/break ratio that should work on Strowger equipment.
Bob Freshwater's site talks about them at http://www.britishtelephones.com/dial1.htm (http://www.britishtelephones.com/dial1.htm), with dials of 50%, 66.6% and 80% break ratios.
:)

Title: Re: GPO fingerplate marked '50% Test'
Post by: Doug Rose on July 01, 2018, 02:38:58 PM
Quote from: FabPhones on July 01, 2018, 11:49:04 AM
I was going through some of the joblot odds and ends this afternoon when I spotted a fingerplate that had received somewhat too much of a rub down. When I looked closer I saw written '50% Test'.

Does anyone know anything about this? It appears to be etched on so no amount of rubbing would remove it but it does look like someone has tried to rub it out.

Pic below.
Any info would be appreciated.
Thanks.

i I think it looks great on the finger wheel. Myself, I would leave it. Are you using sandpaper or a wire brush on the metal?  It looks like it is scratching the metal.  ...Doug
Title: Re: GPO fingerplate marked '50% Test'
Post by: FABphones on July 02, 2018, 02:09:56 AM
It's as I found it at the moment Doug, it does look like someone has had the sandpaper on it. I'll try to polish the scratches out and tidy it up.

Not really sure what to do with it after that. Need a bit more info on it ideally.

Thanks tubaman, I'll check that page out.
Title: Re: GPO fingerplate marked '50% Test'
Post by: ThePillenwerfer on July 24, 2018, 06:18:38 PM
I've just come across the attached on page 10 of Engineering Instructions B5125.
Title: Re: GPO fingerplate marked '50% Test'
Post by: FABphones on July 24, 2018, 06:33:51 PM
Quote from: ThePillenwerfer on July 24, 2018, 06:18:38 PM
I've just come across the attached on page 10 of Engineering Instructions B5125.

Ah-ha.
Thanks for remembering this thread and posting the image.
Very helpful.
:)