29-05-2011, 09:08 PM
(29-05-2011, 07:33 PM)Bushbaby Wrote: Hi Rob,
If I put these in, they complete the heater chain so that the radio works but they do not light at all - any thoughts?
Regards
Rob
The bulbs don't actually 'complete the heater chain', to the extent that if they fail, the shunt resistor (which takes part of the current to the heaters anyway) ensures continuity of the heater chain. One professional restorers fits a small 6V transformer just to power the bulbs. That way, you can use easily obtainable 6V bulbs which stay bright all the time the set is switched on. It can easily be removed later if desired, and I guess it depends on whther one places functionalty above originality. Others have fitted hi brightness LEDs with a series limting resistor, in old bulb bases.
Hope that helps.
David
