Vortexion reel to reel tape recorder WVA series 5 - Page 4 - UK Vintage Radio Repair and Restoration Discussion Forum

Luxman1050 · 28th Oct 2020, 8:42 pm

Is it a shockley diode

Luxman1050 · 28th Oct 2020, 9:07 pm

Em interesting so thyroristor. So it's either on or off no inbetween. So not enough current no latching. So in effect you need to force an increase in current to get it to latch. Plus having a snubber network resistor capacitor. So in effect it seems I've increased the current hence caused it to latch ie open so there obviously was not enough current going through it. I know it's a bit more complicated than that but interesting. So it's not your typical bridge rectifier at all. Or even a normal type of diode.
W V B is different gz30 I have the ez81. Plus 32uf cap not 8uf. So that resistor I changed linked to the valve rectifier depending on switch mode as well as heaters. Em.
Good check tomorrow.

ms660 · 28th Oct 2020, 9:14 pm

I've lost the plot now.

Lawrence.

DMcMahon · 29th Oct 2020, 1:21 pm

Hope I have not confused the issue by suggesting that the bridge rectifier may be at fault.

It was just another area to check out in terms of the bias measurement/set-up, if the bias generation circuitry checked out OK.

David

ms660 · 29th Oct 2020, 1:58 pm

The bridge rectifier/meter circuit would have been the first thing I would have checked.

Lawrence.

barrymagrec · 29th Oct 2020, 7:00 pm

Quote:

Originally Posted by cdm1christopher

Anyone know the exact spec of this diode like I say I've never seen one before its obviously a bridge vf rectifier so low voltage but as usual not having the correct schematic or parts list don't help.
Cheers Chris

It`s a Westinghouse copper oxide rectifier bridge designed specifically as a meter rectifier. They were common in the fifties and sixties, probably before that - I`m fairly sure they are used in some AVOs

If you need to replace it in this application probably a bridge made from any small signal diode would do, germanium or schottky types would be best.

28th Oct 2020, 8:42 pm	#61
Luxman1050 Octode Join Date: Apr 2019 Location: Margate, Kent, UK. Posts: 1,728	Re: Vortexion reel to reel tape recorder WVA series 5 Is it a shockley diode

28th Oct 2020, 9:07 pm	#62
Luxman1050 Octode Join Date: Apr 2019 Location: Margate, Kent, UK. Posts: 1,728	Re: Vortexion reel to reel tape recorder WVA series 5 Em interesting so thyroristor. So it's either on or off no inbetween. So not enough current no latching. So in effect you need to force an increase in current to get it to latch. Plus having a snubber network resistor capacitor. So in effect it seems I've increased the current hence caused it to latch ie open so there obviously was not enough current going through it. I know it's a bit more complicated than that but interesting. So it's not your typical bridge rectifier at all. Or even a normal type of diode. W V B is different gz30 I have the ez81. Plus 32uf cap not 8uf. So that resistor I changed linked to the valve rectifier depending on switch mode as well as heaters. Em. Good check tomorrow.

28th Oct 2020, 9:14 pm	#63
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Vortexion reel to reel tape recorder WVA series 5 I've lost the plot now. Lawrence.

29th Oct 2020, 1:21 pm	#64
DMcMahon Dekatron Join Date: Apr 2019 Location: Worthing, West Sussex, UK. Posts: 6,600	Re: Vortexion reel to reel tape recorder WVA series 5 Hope I have not confused the issue by suggesting that the bridge rectifier may be at fault. It was just another area to check out in terms of the bias measurement/set-up, if the bias generation circuitry checked out OK. David

29th Oct 2020, 1:58 pm	#65
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Vortexion reel to reel tape recorder WVA series 5 The bridge rectifier/meter circuit would have been the first thing I would have checked. Lawrence.