|
Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
|
Thread Tools |
18th Apr 2013, 12:46 pm | #21 | |
Dekatron
Join Date: Feb 2007
Location: Lynton, N. Devon, UK.
Posts: 7,061
|
Re: Bush DAC90A. Dial lamps.
Quote:
If you switch on the radio without the lamps, then that set will still work because of the shunt resistor. This will carry a higher current of course, but no other problem. If the shunt resistor burns out, then yes the heater chain will be broken. But so will the chassis connection to mains neutral. So everything will go out, but the heater-cathode insulation will not be stressed because the heater chain is taken direct to chassis, so heater-cathode potentials will drop to zero. |
|
18th Apr 2013, 2:46 pm | #22 |
Octode
Join Date: Nov 2005
Location: Surrey, UK.
Posts: 1,869
|
Re: Bush DAC90A. Dial lamps.
Quite correct - my oversight. Thanks for pointing this out, I must work on these sets more often. The trouble is, once restored, they're very reliable.
Leon. |
18th Apr 2013, 2:56 pm | #23 |
Rest in Peace
Join Date: May 2003
Location: Harlaxton, Lincolnshire, UK.
Posts: 3,944
|
Re: Bush DAC90A. Dial lamps.
Also to be fair Leon, there is a good chance my inaccuracy in post 17 (that I corrected in post 20) may have planted in your mind the idea that the bulbs were in the heater chain.
Colin M |
19th Apr 2013, 10:52 pm | #24 |
Heptode
Join Date: Apr 2013
Location: Bloxwich, West Midlands, UK
Posts: 554
|
Re: Bush DAC90A. Dial lamps.
Hi Glowing bits,
I checked the mains dropper, it's not green so I guess it's an earlier model. Gary |
20th Apr 2013, 3:13 am | #25 |
Octode
Join Date: Oct 2011
Location: Wrexham, North Wales, UK.
Posts: 1,457
|
Re: Bush DAC90A. Dial lamps.
Gary, I'll get the set out the cupboard and have a look at the serial to see if it's anywhere near to yours.
It would appear that your set is an earlier example. |
20th Apr 2013, 5:50 pm | #26 |
Pentode
Join Date: Jan 2013
Location: Immingham, North East Lincolnshire, UK.
Posts: 174
|
Re: Bush DAC90A. Dial lamps.
Re Bush Dac90 dial lamps.
I use two 12v 100Ma lamps with 560R shunt. when fully warmed up scale is slightly brighter than stock. Just bought another set that has standard lamps and shunt resistor and the difference is noticeable. |