Champion 784 or is it? - UK Vintage Radio Repair and Restoration Discussion Forum

1955APREN · 2nd Nov 2019, 9:09 am

This little bakelite set as arrived from a friend who runs a S/H shop. With request
can i get it working.
I think it is a TRF MW only , valve line up is 6BJ6,6BM6, 50L6 & a octal base rectifier ( number rubbed off) .
The back of the radio is the same size as the cabinet but the screws that hold the back on are not in the corners, someone has drilled two holes in the chassis and used self tapping screws with spacers to hold the back on.
The back clearly states that the mains lead should Never be shortened . this would indicate that the set should have been powered with a line cord. but the main lead is just a two core type. This makes me wonder if the back is the correct one for the set , if not then the model No is incorrect.
Does any one know if there two version of this set or is there another model that uses
this valve line up
thanks for any help
Derrick

Cobaltblue · 2nd Nov 2019, 9:27 am

Pictures?

Cheers

Mike T

Sideband · 2nd Nov 2019, 10:28 am

This Champion set came in several versions. The first was fitted with 6BA6, 6AM6, 25L6 and 25Z4. The later version was fitted with 6BJ6, 6BH6, 35L6 or 50L6 and 35Z4. I think the first version was fitted with a line cord, the second with a dropper and normal twin cable for mains.

Circuit is available from this forum. Click the panel at top right.

That back panel sounds dangerous.....the set has a live chassis and possibly those back screws will be live as well.

Herald1360 · 2nd Nov 2019, 4:45 pm

Doesn't sound like a set to be sold on to Joe Public unless you can be sure it's restoired to exactly as originally built. Even then.......?

Ed_Dinning · 2nd Nov 2019, 8:30 pm

Hi Derrick, as has been said there were several versions of this set, not all well documented.
If it was fitted with a line cord originally this may have been replaced with a resistive or capacitive dropper. Capacitive is to be preferred as the cabinet then runs much cooler.

Ed

Heatercathodeshort · 3rd Nov 2019, 3:25 pm

Certainly many versions of it. This one : 6BA6 6BJ6 35L6 35Z4. It incorporated a mains dropper from the start. The back has the mains lead warning but I think they just used the one style of back.
The photo shows the special chassis insulators and spacers for the back and bottom with their removable caps. I doubt if many still retain these.
I would certainly agree. I would be most unhappy passing this on to a member of the public who were not aware of the implications [Volume knob becoming loose etc.] with regard to a live chassis radio that could end up in a kitchen or even a bathroom.
They are attractive and easy to repair but performance is generally a bit lack lustre to say the least. John.

1955APREN · 4th Nov 2019, 8:46 am

Thanks everyone for all the supplied inf regarding this set. Yes the safety factor regarding this set as much to be desired . I have made a more detailed inspection of the set and it as not been worked on b4. In my 1st post I made a mistake regarding the valve line up it is 6BJ6 , 6BH6 , 50L6 35Z4 . The 6BH6 as
gone two air ( cracked) so this will have to be replaced.
John's Photos are spot on , but as Johns say's the back and chassis holding screw's have lost there end caps , but new plastic one could be fitted. Another thing that I have noticed is that the signal pole on/off sw is switching the neutral
( black) lead . this means with set switched off the chassis will be LIVE via the heater circuit .
I will inform the owner of all this and see how much to spend on this radio.
Thanks again for all your help
Derrick

TonyDuell · 4th Nov 2019, 10:03 am

Those self-tapping screws with caps look like the ones used to fix car number plates. You might get replacements in a car accessory shop. But I feel that having such screws going into a chassis which is certain to be live at some point is safe. Can you not fix the back to the corner pillars in the case?

2nd Nov 2019, 9:09 am	#1
1955APREN Hexode Join Date: Nov 2010 Location: Market Drayton, Shropshire, UK. Posts: 486	Champion 784 or is it? This little bakelite set as arrived from a friend who runs a S/H shop. With request can i get it working. I think it is a TRF MW only , valve line up is 6BJ6,6BM6, 50L6 & a octal base rectifier ( number rubbed off) . The back of the radio is the same size as the cabinet but the screws that hold the back on are not in the corners, someone has drilled two holes in the chassis and used self tapping screws with spacers to hold the back on. The back clearly states that the mains lead should Never be shortened . this would indicate that the set should have been powered with a line cord. but the main lead is just a two core type. This makes me wonder if the back is the correct one for the set , if not then the model No is incorrect. Does any one know if there two version of this set or is there another model that uses this valve line up thanks for any help Derrick

2nd Nov 2019, 9:27 am	#2
Cobaltblue Moderator Join Date: Dec 2010 Location: Exeter, Devon and Poole, Dorset UK. Posts: 6,878	Re: Champion 784 or is it . Pictures? Cheers Mike T __________________ Invisible airwaves crackle with life or at least they used to Mike T BVWS member. www.cossor.co.uk

2nd Nov 2019, 10:28 am	#3
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,580	Re: Champion 784 or is it . This Champion set came in several versions. The first was fitted with 6BA6, 6AM6, 25L6 and 25Z4. The later version was fitted with 6BJ6, 6BH6, 35L6 or 50L6 and 35Z4. I think the first version was fitted with a line cord, the second with a dropper and normal twin cable for mains. Circuit is available from this forum. Click the panel at top right. That back panel sounds dangerous.....the set has a live chassis and possibly those back screws will be live as well. __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

2nd Nov 2019, 4:45 pm	#4
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,536	Re: Champion 784 or is it . Doesn't sound like a set to be sold on to Joe Public unless you can be sure it's restoired to exactly as originally built. Even then.......? __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

2nd Nov 2019, 8:30 pm	#5
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,195	Re: Champion 784 or is it . Hi Derrick, as has been said there were several versions of this set, not all well documented. If it was fitted with a line cord originally this may have been replaced with a resistive or capacitive dropper. Capacitive is to be preferred as the cabinet then runs much cooler. Ed

3rd Nov 2019, 3:25 pm	#6
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Champion 784 or is it . Certainly many versions of it. This one : 6BA6 6BJ6 35L6 35Z4. It incorporated a mains dropper from the start. The back has the mains lead warning but I think they just used the one style of back. The photo shows the special chassis insulators and spacers for the back and bottom with their removable caps. I doubt if many still retain these. I would certainly agree. I would be most unhappy passing this on to a member of the public who were not aware of the implications [Volume knob becoming loose etc.] with regard to a live chassis radio that could end up in a kitchen or even a bathroom. They are attractive and easy to repair but performance is generally a bit lack lustre to say the least. John. Attached Thumbnails Last edited by Heatercathodeshort; 3rd Nov 2019 at 3:30 pm.

4th Nov 2019, 8:46 am	#7
1955APREN Hexode Join Date: Nov 2010 Location: Market Drayton, Shropshire, UK. Posts: 486	Re: Champion 784 or is it . Thanks everyone for all the supplied inf regarding this set. Yes the safety factor regarding this set as much to be desired . I have made a more detailed inspection of the set and it as not been worked on b4. In my 1st post I made a mistake regarding the valve line up it is 6BJ6 , 6BH6 , 50L6 35Z4 . The 6BH6 as gone two air ( cracked) so this will have to be replaced. John's Photos are spot on , but as Johns say's the back and chassis holding screw's have lost there end caps , but new plastic one could be fitted. Another thing that I have noticed is that the signal pole on/off sw is switching the neutral ( black) lead . this means with set switched off the chassis will be LIVE via the heater circuit . I will inform the owner of all this and see how much to spend on this radio. Thanks again for all your help Derrick

4th Nov 2019, 10:03 am	#8
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,224	Re: Champion 784 or is it? Those self-tapping screws with caps look like the ones used to fix car number plates. You might get replacements in a car accessory shop. But I feel that having such screws going into a chassis which is certain to be live at some point is safe. Can you not fix the back to the corner pillars in the case?