Ultra Troubadour. Panel Lamp. - UK Vintage Radio Repair and Restoration Discussion Forum

Pyeeye1749# · 25th Oct 2024, 11:55 am

Hi. Any problems using 200mA 3.5 volt bulb instead of 150mA as per Trader sheet on a Ultra Troubadour?

Many thanks.

mister valve · 25th Oct 2024, 5:31 pm

If it is part of the heater chain, then it will probably light up slightly dimmer. I don't know this particular set or circuit, but I doubt it would cause any damage.

kestrelmusic · 27th Oct 2024, 3:59 pm

Quote:

Originally Posted by Pyeeye1749#

Hi. Any problems using 200mA 3.5 volt bulb instead of 150mA as per Trader sheet on a Ultra Troubadour?

Many thanks.

You'll need to alter the value of the shunt resistor (R15 on Trader sheet 1038, and assumiung that it's this model - there were several Troubadour models).

Alternatively use a 6.3V or 6V 150mA lamp which are easily obtained. Again you'll need to alter the value of R15. Experiment to see what works best.

25th Oct 2024, 11:55 am	#1
Pyeeye1749# Diode Join Date: Jul 2022 Location: Huntley, Gloucester, UK. Posts: 2	Ultra Troubadour. Panel Lamp. Hi. Any problems using 200mA 3.5 volt bulb instead of 150mA as per Trader sheet on a Ultra Troubadour? Many thanks.

25th Oct 2024, 5:31 pm	#2
mister valve Hexode Join Date: Aug 2009 Location: Blackpool, Lancashire, UK. Posts: 326	Re: Ultra Troubadour. Panel Lamp. If it is part of the heater chain, then it will probably light up slightly dimmer. I don't know this particular set or circuit, but I doubt it would cause any damage. __________________ If you live, the chassis was dead; if you're dead, the chassis was live !!!!