DAC 90A dial lamps - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

pichacker · 27th Jan 2011, 4:10 pm

Not bad for my age I suppose

If I look directly at them then no, but off the side yes in much the same way as screen flicker on a computer CRT monitor or TV set.

Maybe the fillaments are also thinner hence less thermal inertia?

Good point about the resistance change with respect to temperature. Now where did I put that Barretta..?

Sideband · 27th Jan 2011, 4:35 pm

Quote:

Originally Posted by pichacker

SB,

If the two bulbs are 100ma, how much is going though the bulbs and how much is passing in the parallel resistor.

To be honest, I haven't a clue! I restored the set a while ago and after fitting the lamps and seeing that the brightness was adequate, I just boxed it up and used it. I could check the voltage and I have access to a true RMS meter but it won't be just yet. The meter is at work and I won't be there until Monday. I could take a reading on my ordinary digital and also the analogue. May be able to check tonight but I have no heating in the W/S at the moment and it's trying to snow.....!

SB

pbellsf · 2nd May 2011, 1:10 pm

Thanks for all the posts to my original questions. Eventually gave up on bulb combinations and fitted a transformer from inside an old phone charger which wedged into the scale supports nicely and used 2.5v bulbs in parallel. Always prefer to keep radios as original as possible but you have to give in eventually.

pichacker · 3rd May 2011, 8:10 am

Glad you're happy however I have done 5 radios withthe bulb combinations mentioned earlier without any problems.

fusewire · 3rd May 2011, 11:30 pm

LEDs, no way!

Come on lads, next you'll be fitting audio output chips. They're old radios, not hybrids.

pichacker · 4th May 2011, 7:23 am

Exactly my point, I did try a transformer in one of mine but this just didn't feel right as I kind of liked the bright, dim, bright behaviour of the original lamp circuit a switch on.

However, if the radio is kept going and and the OP is happy then this is a good thing.

27th Jan 2011, 4:10 pm	#21
pichacker Hexode Join Date: Aug 2008 Location: Essex, UK. Posts: 370	Re: DAC 90A dial lamps Not bad for my age I suppose If I look directly at them then no, but off the side yes in much the same way as screen flicker on a computer CRT monitor or TV set. Maybe the fillaments are also thinner hence less thermal inertia? Good point about the resistance change with respect to temperature. Now where did I put that Barretta..? __________________ 6.3v on my heaters is no longer enough to get me going in the morning!!

2nd May 2011, 1:10 pm	#23
pbellsf Retired Dormant Member Join Date: Jun 2010 Location: Durham, County Durham, UK. Posts: 8	Re: DAC 90A dial lamps Thanks for all the posts to my original questions. Eventually gave up on bulb combinations and fitted a transformer from inside an old phone charger which wedged into the scale supports nicely and used 2.5v bulbs in parallel. Always prefer to keep radios as original as possible but you have to give in eventually.

3rd May 2011, 8:10 am	#24
pichacker Hexode Join Date: Aug 2008 Location: Essex, UK. Posts: 370	Re: DAC 90A dial lamps Glad you're happy however I have done 5 radios withthe bulb combinations mentioned earlier without any problems. __________________ 6.3v on my heaters is no longer enough to get me going in the morning!!

3rd May 2011, 11:30 pm	#25
fusewire Retired Dormant Member Join Date: Feb 2011 Location: Moreton, Wirral, Merseyside. Posts: 27	Re: DAC 90A dial lamps LEDs, no way! Come on lads, next you'll be fitting audio output chips. They're old radios, not hybrids. Last edited by Brian R Pateman; 4th May 2011 at 8:38 pm. Reason: Translation.

4th May 2011, 7:23 am	#26
pichacker Hexode Join Date: Aug 2008 Location: Essex, UK. Posts: 370	Re: DAC 90A dial lamps Exactly my point, I did try a transformer in one of mine but this just didn't feel right as I kind of liked the bright, dim, bright behaviour of the original lamp circuit a switch on. However, if the radio is kept going and and the OP is happy then this is a good thing.