GEC BC402 receiver. - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

Dorian27 · 6th May 2021, 11:00 pm

No I haven't checked its values I just noticed it got very hot

Cobaltblue · 6th May 2021, 11:13 pm

Ok if its got hot can you be sure of the colours?

That could be red violet brown or 270 ohms.

Is it the cathode resistor of the output valve ?

The output valve might be drawing too much current due to a leaky coupling capacitor. What value does the service sheet say it should be?

Cheers

Mike T

Station X · 7th May 2021, 7:31 am

A model number for the radio would help.

HamishBoxer · 7th May 2021, 8:10 am

I will go for 270 Ohm and there is possibly a service sheet top right of this page, instant download if you have not got one, for what ever the model is.

There will be a few waxy caps that need replacing , so a service sheet would help.

ms660 · 7th May 2021, 12:04 pm

GEC BC402....270 Ohms?

Lawrence.

Dorian27 · 7th May 2021, 4:00 pm

Yes it is a GEC402 RESISTOR IF THE COUPLING CAPACITOR IS MAKING THE RESISTOR HOT WHICH IS THE COUPLING CAPACITOR AS I AM ANOVICE AT THIS. AND WHAT TYPE OF CAPACITOR WOULD I NEED IN VALU AND TYPE PLEASE. SORRY ABOUT THIS BUT I'D RATHER GET IT CORRECT THANK YOU ALL FOR ANY HELP. FT

ms660 · 7th May 2021, 4:16 pm

C48 in the schematic I'm looking at (radiomuseum) Use one of these or similar:

https://www.cricklewoodelectronics.com/CFH47N.html

Lawrence.

snowman_al · 7th May 2021, 5:26 pm

That is C54 on the Trader Sheet 1489.
Same thing 0.047uF 400 volts.

Might be a good idea to measure the actual resistance of the 270Ω resistor (with the set off and disconnected) and then then actual voltage across it?

Station X · 7th May 2021, 5:41 pm

Threads merged.

6th May 2021, 11:00 pm	#21
Dorian27 Heptode Join Date: Jun 2018 Location: Carmarthenshire, Wales, UK. Posts: 564	Re: Gec Radio No I haven't checked its values I just noticed it got very hot

6th May 2021, 11:13 pm	#22
Cobaltblue Moderator Join Date: Dec 2010 Location: Exeter, Devon and Poole, Dorset UK. Posts: 6,865	Re: Gec Radio Ok if its got hot can you be sure of the colours? That could be red violet brown or 270 ohms. Is it the cathode resistor of the output valve ? The output valve might be drawing too much current due to a leaky coupling capacitor. What value does the service sheet say it should be? Cheers Mike T __________________ Invisible airwaves crackle with life or at least they used to Mike T BVWS member. www.cossor.co.uk

7th May 2021, 7:31 am	#23
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Gec Radio A model number for the radio would help. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

7th May 2021, 8:10 am	#24
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,932	Re: Gec Radio I will go for 270 Ohm and there is possibly a service sheet top right of this page, instant download if you have not got one, for what ever the model is. There will be a few waxy caps that need replacing , so a service sheet would help. __________________ G8JET BVWS Archivist and Member V.M.A.R.S

7th May 2021, 12:04 pm	#25
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: GEC Radio GEC BC402....270 Ohms? Lawrence.

7th May 2021, 4:00 pm	#26
Dorian27 Heptode Join Date: Jun 2018 Location: Carmarthenshire, Wales, UK. Posts: 564	Re: GEC Radio Yes it is a GEC402 RESISTOR IF THE COUPLING CAPACITOR IS MAKING THE RESISTOR HOT WHICH IS THE COUPLING CAPACITOR AS I AM ANOVICE AT THIS. AND WHAT TYPE OF CAPACITOR WOULD I NEED IN VALU AND TYPE PLEASE. SORRY ABOUT THIS BUT I'D RATHER GET IT CORRECT THANK YOU ALL FOR ANY HELP. FT

7th May 2021, 4:16 pm	#27
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: GEC Radio C48 in the schematic I'm looking at (radiomuseum) Use one of these or similar: https://www.cricklewoodelectronics.com/CFH47N.html Lawrence. Last edited by ms660; 7th May 2021 at 4:19 pm. Reason: extra info

7th May 2021, 5:26 pm	#28
snowman_al Octode Join Date: Dec 2018 Location: Llandeilo, West Wales, UK. Posts: 1,092	Re: GEC Radio That is C54 on the Trader Sheet 1489. Same thing 0.047uF 400 volts. Might be a good idea to measure the actual resistance of the 270Ω resistor (with the set off and disconnected) and then then actual voltage across it? Attached Thumbnails __________________ Never Leave Well Enough Alone...

7th May 2021, 5:41 pm	#29
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: GEC BC402 receiver. Threads merged. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.