Champion 860 - Page 3 - UK Vintage Radio Repair and Restoration Discussion Forum

vidjoman · 8th Nov 2019, 9:48 am

"I can spray the UF85's socket with DeOxIt." NOT recommended - just apply a small amount to the valve pins and push the valve in/out a few times.
Spraying the sockets can result in the material becoming conductive with dirt holding the spray and tracking between pins.

Sideband · 8th Nov 2019, 10:27 am

I thought it was supposed to be a UF89? Whatever is fitted DON'T spray the valve socket for the reasons stated above. UF85 and UF89 are pin compatible but have different characteristics. The heater voltage is lower for the UF89 (12.6v) as opposed to 19v for the UF85. I think the UF89 was a lower noise valve.

These sets usually give a good account of themselves....far better than they have any business to. I seem to recall they do use rather cheap paxolin valveholders that give trouble so don't be surprised if any amount of spraying or cleaning doesn't help. The answer will be to change the valveholder...not too bad a job in these sets

Neil Purling · 8th Nov 2019, 5:45 pm

My mistake. I have looked & V1 is a UF89. I wiggled about all the valves & it works again. Changing the valveholders probably would be a good idea. Perhaps to change the high value resistors at the same time. There's really not a lot inside this set.
Does anyone know what type the tiny cream slab capacitors across some of the coils actually are? they are 6.8pf, 10pf and 300pf & there's a 1000pf de-coupler on the anode of the UCL83 triode section that is the detector. The big one looks like a mica type. Not sure of those other ones.

Neil Purling · 11th Nov 2019, 2:24 pm

I am going to need a knob with a very short shaft & spring clip that will fit over the 'D' shaped 1/4" tuning shaft. The original tuning knob had a tiny bot of plastic break off in the centre when I removed the knob.
This was despite using a pair of bootlaces and a hair-dryer to heat the centre & make it expand.
I could get the original knob back on, but it wont stay on without I use hot-melt glue. I was very angry at myself when that happened despite taking those precautions.

8th Nov 2019, 9:48 am	#41
vidjoman Dekatron Join Date: Jun 2013 Location: East Sussex, UK. Posts: 3,326	Re: Champion 860 "I can spray the UF85's socket with DeOxIt." NOT recommended - just apply a small amount to the valve pins and push the valve in/out a few times. Spraying the sockets can result in the material becoming conductive with dirt holding the spray and tracking between pins.

8th Nov 2019, 10:27 am	#42
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,578	Re: Champion 860 I thought it was supposed to be a UF89? Whatever is fitted DON'T spray the valve socket for the reasons stated above. UF85 and UF89 are pin compatible but have different characteristics. The heater voltage is lower for the UF89 (12.6v) as opposed to 19v for the UF85. I think the UF89 was a lower noise valve. These sets usually give a good account of themselves....far better than they have any business to. I seem to recall they do use rather cheap paxolin valveholders that give trouble so don't be surprised if any amount of spraying or cleaning doesn't help. The answer will be to change the valveholder...not too bad a job in these sets __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman..... Last edited by Sideband; 8th Nov 2019 at 10:40 am.

8th Nov 2019, 5:45 pm	#43
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,087	Re: Champion 860 My mistake. I have looked & V1 is a UF89. I wiggled about all the valves & it works again. Changing the valveholders probably would be a good idea. Perhaps to change the high value resistors at the same time. There's really not a lot inside this set. Does anyone know what type the tiny cream slab capacitors across some of the coils actually are? they are 6.8pf, 10pf and 300pf & there's a 1000pf de-coupler on the anode of the UCL83 triode section that is the detector. The big one looks like a mica type. Not sure of those other ones.

11th Nov 2019, 2:24 pm	#44
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,087	Re: Champion 860 I am going to need a knob with a very short shaft & spring clip that will fit over the 'D' shaped 1/4" tuning shaft. The original tuning knob had a tiny bot of plastic break off in the centre when I removed the knob. This was despite using a pair of bootlaces and a hair-dryer to heat the centre & make it expand. I could get the original knob back on, but it wont stay on without I use hot-melt glue. I was very angry at myself when that happened despite taking those precautions.