GEC BC5442 receiver. - UK Vintage Radio Repair and Restoration Discussion Forum

bikelectro · 27th Oct 2018, 1:42 pm

Have to do an economic repair/overhaul on this set.
Main fault was the dial cord. The set has been in a warm house all its life and worked fairly well when I tried it, repaired dial drive, cleaned switches, controls and valve pins, quick rub over with scratch cover and cabinet quite nice.
The brown GEC waxies seem fine but the light coloured Hunts .022uF in centre of pic is slightly leaky.
I’m thinking to fit a 250mA fuse for safety and changing the 2 Hunts .022uF caps, is one of these the “THAT” cap, if not which is? Also where best to fit the fuse? Appreciate any thoughts, thanks!

cathoderay57 · 27th Oct 2018, 2:43 pm

Hi there. If you haven't already done so I recommend you buy the service sheet here https://www.service-data.com/search....&search=Search Referring to the Trader Sheet #1026, C21 is "that cap" 0.02uF with one end connected to the anode of V3 (DH77). Be careful as there is more than one 0.02uF cap in this set. I cannot tell from your image: you need to trace the component to V3 valve socket. You say the waxies seem fine but I wonder how you tested them for leakage? It's also worth doing a leakage test of the main HT electrolytics even if there is little or no hum as leakage in these will reduce the life of the rectifier and in rare cases they can explode if they get hot. It's a good idea to fit a fuse to protect the transformer. You should have a 2A or at most 3A fuse in the mains plug. To protect the secondary HT winding of the transformer I recommend that you disconnect the wire between the centre tap of the HT winding and chassis and fit a small 20mm fuse holder in its place. 100mA fuse is plenty as even with 100% valves (which is very unlikely) the set only draws 37mA (so a 250mA fuse is too heavy). Hope that helps. Cheers, Jerry

bikelectro · 29th Oct 2018, 10:10 am

Thanks Jerry,
This really is a basic but very good set! I played it for about 4 hours, smoother block not warm, o/p trans absolutely cool and mains TX just nicely warm, As usual the lettering is about to fall off the glass, but lucky it isn't very dirty.
I just have high ohms to check the caps, but voltages taken seem to indicate no leaks under voltage with the large brown ones. I will change the two Hunts and audio cap ( probably one of the Hunts is it ) Good idea for the fuse - I will fit that and have fitted 1A plug fuse. The original mains lead is still good!

27th Oct 2018, 2:43 pm	#2
cathoderay57 Nonode Join Date: Oct 2017 Location: Bristol, UK. Posts: 2,389	Re: Gec bc5442 Hi there. If you haven't already done so I recommend you buy the service sheet here https://www.service-data.com/search....&search=Search Referring to the Trader Sheet #1026, C21 is "that cap" 0.02uF with one end connected to the anode of V3 (DH77). Be careful as there is more than one 0.02uF cap in this set. I cannot tell from your image: you need to trace the component to V3 valve socket. You say the waxies seem fine but I wonder how you tested them for leakage? It's also worth doing a leakage test of the main HT electrolytics even if there is little or no hum as leakage in these will reduce the life of the rectifier and in rare cases they can explode if they get hot. It's a good idea to fit a fuse to protect the transformer. You should have a 2A or at most 3A fuse in the mains plug. To protect the secondary HT winding of the transformer I recommend that you disconnect the wire between the centre tap of the HT winding and chassis and fit a small 20mm fuse holder in its place. 100mA fuse is plenty as even with 100% valves (which is very unlikely) the set only draws 37mA (so a 250mA fuse is too heavy). Hope that helps. Cheers, Jerry

29th Oct 2018, 10:10 am	#3
bikelectro Pentode Join Date: Jun 2008 Location: Northern Ireland. Posts: 158	Re: Gec bc5442 Thanks Jerry, This really is a basic but very good set! I played it for about 4 hours, smoother block not warm, o/p trans absolutely cool and mains TX just nicely warm, As usual the lettering is about to fall off the glass, but lucky it isn't very dirty. I just have high ohms to check the caps, but voltages taken seem to indicate no leaks under voltage with the large brown ones. I will change the two Hunts and audio cap ( probably one of the Hunts is it ) Good idea for the fuse - I will fit that and have fitted 1A plug fuse. The original mains lead is still good!

27th Oct 2018, 1:42 pm	#1
bikelectro Pentode Join Date: Jun 2008 Location: Northern Ireland. Posts: 158	GEC BC5442 receiver. Have to do an economic repair/overhaul on this set. Main fault was the dial cord. The set has been in a warm house all its life and worked fairly well when I tried it, repaired dial drive, cleaned switches, controls and valve pins, quick rub over with scratch cover and cabinet quite nice. The brown GEC waxies seem fine but the light coloured Hunts .022uF in centre of pic is slightly leaky. I’m thinking to fit a 250mA fuse for safety and changing the 2 Hunts .022uF caps, is one of these the “THAT” cap, if not which is? Also where best to fit the fuse? Appreciate any thoughts, thanks! Attached Thumbnails