Unknown but working - UK Vintage Radio Repair and Restoration Discussion Forum

rsedwards1 · 3rd Apr 2018, 6:37 pm

Anyone know what this unit is? it aperars to be working thought it was a signal generator at first , but it has scale reading in ohms and micofarads mabe a capacitor tester the magic eye valve is working and the output terminals shows a sine wave varable . Had this over 30 years been in the garden shed , amazing it seams to work what ever it is.

llama · 3rd Apr 2018, 6:47 pm

I imagine it's a resistor and capacitor measuring bridge. An oscillator in there would be the input to the bridge and the magic eye would be across the bridge to identify the null.
Graham

Ed_Dinning · 3rd Apr 2018, 7:59 pm

It looks like a piece of home brew kit built into some ex-gov case.

There were several designs associated with PW, Radio constructor etc in the 50's.
If you know the valves it may be possible to trace its origins from there.

Ed

The Philpott · 3rd Apr 2018, 8:15 pm

Certainly is a bitzer- Belling Lee terminals and Paignton (Paynton?) knobs, and the indicator light and connectors look MOD origin. I bet you won't ever see another one..

Sideband · 3rd Apr 2018, 8:56 pm

Definitely home-brew. The scale gives it away as everything is hand-written. Yes it would be interesting to try and find the design so perhaps try to identify the valves used. Probably dates to the 50's when lots of Army Surplus gear was available.

rsedwards1 · 3rd Apr 2018, 9:33 pm

Quote:

Originally Posted by llama

I imagine it's a resistor and capacitor measuring bridge. An oscillator in there would be the input to the bridge and the magic eye would be across the bridge to identify the null.
Graham

I think you are right , i put a capacitor acreoss the terminals and the magic eye closed off to about half . The Valves have typical WD ^ markings on them not checked the part numbers

Refugee · 3rd Apr 2018, 10:33 pm

It does look like an AC R/C bridge.
I have got a Phillips factory made one that just does resistance but with an external decade box will also do capacitance.
It has been superseded by a very posh Marconi one that I recently restored.

3rd Apr 2018, 6:37 pm	#1
rsedwards1 Triode Join Date: Dec 2017 Location: Great Yarmouth, Norfolk, UK. Posts: 15	Unknown but working Anyone know what this unit is? it aperars to be working thought it was a signal generator at first , but it has scale reading in ohms and micofarads mabe a capacitor tester the magic eye valve is working and the output terminals shows a sine wave varable . Had this over 30 years been in the garden shed , amazing it seams to work what ever it is. Attached Thumbnails

3rd Apr 2018, 6:47 pm	#2
llama Octode Join Date: Jun 2006 Location: St Osyth, Nr Clacton, Essex, UK. Posts: 1,482	Re: Unknown but working I imagine it's a resistor and capacitor measuring bridge. An oscillator in there would be the input to the bridge and the magic eye would be across the bridge to identify the null. Graham __________________ Half my stuff is junk - trouble is, I don't know which half!

3rd Apr 2018, 7:59 pm	#3
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,194	Re: Unknown but working It looks like a piece of home brew kit built into some ex-gov case. There were several designs associated with PW, Radio constructor etc in the 50's. If you know the valves it may be possible to trace its origins from there. Ed

3rd Apr 2018, 8:15 pm	#4
The Philpott Dekatron Join Date: Aug 2016 Location: Colchester, Essex, UK. Posts: 4,104	Re: Unknown but working Certainly is a bitzer- Belling Lee terminals and Paignton (Paynton?) knobs, and the indicator light and connectors look MOD origin. I bet you won't ever see another one..

3rd Apr 2018, 8:56 pm	#5
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,566	Re: Unknown but working Definitely home-brew. The scale gives it away as everything is hand-written. Yes it would be interesting to try and find the design so perhaps try to identify the valves used. Probably dates to the 50's when lots of Army Surplus gear was available. __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

3rd Apr 2018, 10:33 pm	#7
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,553	Re: Unknown but working It does look like an AC R/C bridge. I have got a Phillips factory made one that just does resistance but with an external decade box will also do capacitance. It has been superseded by a very posh Marconi one that I recently restored.