J - J Phasor Meter - UK Vintage Radio Repair and Restoration Discussion Forum

David Simpson · 15th Jun 2016, 2:59 pm

Just wondering, would these items have been used by degree students at a University back in the early 70's ? Obviously they have no use in vintage radio circles, but are jolly well made.
Yes, I can vaguely remember the j notation & basic phasor diagrams from ONC/HNC studies nearly 45 years ago. So don't need a maths lesson. But would like some background info,(&/or a circuit diagram), before contemplating using their components for other future workshop projects.

Regards, David

Radio Wrangler · 15th Jun 2016, 3:06 pm

Obviously power electronics courses are very interested in phase, then there's general circuit theory, but one big field where phase measurement is critical is navigation instrumentation. Decca, ADF, VOR etc.

I'll wait for the bits to turn up in photos of a valve tester

David

David Simpson · 15th Jun 2016, 4:09 pm

Yes David, those lovely sloped cabinets have already sparked thoughts of a another hybrid valve testing project. Me thinks that a recently acquired 45B might perhaps be re-clothed. I hope that not too many hands are being wringed in horror. However, with two or three other projects in the queue, it'll be 2017 before a decision is made.
Meanwhile, reminiscences from ex degree students would be of great interest, nae doot, and appreciated.
Decca eh ? I spent a couple of years working on the Decca Nav Mk8 equipment over 50 years ago. Boy, did I struggle. Much easier to work on 'Shipmate' when they adapted the transmissions in the 80's.

Regards, David

coil1234 · 15th Jun 2016, 4:43 pm

Hello David,
I would have said these were made by JJ Lloyd ( latterly Lloyd Instruments), who it would appear are still in business;
http://www.lloyd-instruments.co.uk.

When I worked in the standards room at Marconi Communications we had a JJ Lloyd resistance box as our working resistance standard.

These seem to date from the time when I did my transmission line theory, when j was the square root of -1.

Regards
Mike A

15th Jun 2016, 2:59 pm	#1
David Simpson Nonode Join Date: Mar 2008 Location: Aberdeen, UK. Posts: 2,859	J - J Phasor Meter Just wondering, would these items have been used by degree students at a University back in the early 70's ? Obviously they have no use in vintage radio circles, but are jolly well made. Yes, I can vaguely remember the j notation & basic phasor diagrams from ONC/HNC studies nearly 45 years ago. So don't need a maths lesson. But would like some background info,(&/or a circuit diagram), before contemplating using their components for other future workshop projects. Regards, David Attached Thumbnails

15th Jun 2016, 3:06 pm	#2
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,903	Re: J - J Phasor Meter Obviously power electronics courses are very interested in phase, then there's general circuit theory, but one big field where phase measurement is critical is navigation instrumentation. Decca, ADF, VOR etc. I'll wait for the bits to turn up in photos of a valve tester David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

15th Jun 2016, 4:09 pm	#3
David Simpson Nonode Join Date: Mar 2008 Location: Aberdeen, UK. Posts: 2,859	Re: J - J Phasor Meter Yes David, those lovely sloped cabinets have already sparked thoughts of a another hybrid valve testing project. Me thinks that a recently acquired 45B might perhaps be re-clothed. I hope that not too many hands are being wringed in horror. However, with two or three other projects in the queue, it'll be 2017 before a decision is made. Meanwhile, reminiscences from ex degree students would be of great interest, nae doot, and appreciated. Decca eh ? I spent a couple of years working on the Decca Nav Mk8 equipment over 50 years ago. Boy, did I struggle. Much easier to work on 'Shipmate' when they adapted the transmissions in the 80's. Regards, David

15th Jun 2016, 4:43 pm	#4
coil1234 Pentode Join Date: Jan 2006 Location: Almeria, Spain Posts: 221	Re: J - J Phasor Meter Hello David, I would have said these were made by JJ Lloyd ( latterly Lloyd Instruments), who it would appear are still in business; http://www.lloyd-instruments.co.uk. When I worked in the standards room at Marconi Communications we had a JJ Lloyd resistance box as our working resistance standard. These seem to date from the time when I did my transmission line theory, when j was the square root of -1. Regards Mike A