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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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18th May 2022, 7:46 pm | #1 |
Diode
Join Date: May 2022
Location: Bude, North Cornwall, UK.
Posts: 2
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Bush VHF71. My first restoration!
Hi all, Im a new member! my background is in tv servicing in the 90's and 00's. I left the trade as there was little call for repairs, and now repair commercial coffee machines.
This is my first experience of valve equipment just some help please, i have a Bush vhf71 receiver. both illumination bulbs are gone and i want to replace them. they should be 6.3v 0.115a according to the bush service manual, however the more populat 6.3v 0.15a bulbs seem available. However there are notes in the back of the manual saying these bulbs shouldnt be fitted as they can cause issues with the rectifier valve. I see from the schematic that the bulbs are part of the current limiting in the supply of the set. Whats your thoughts please . thanks Darren |
19th May 2022, 10:51 am | #2 |
Nonode
Join Date: Mar 2008
Location: Virginia Water, Surrey, UK.
Posts: 2,872
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Re: Bush VHF71. My first restoration!
Crude ohms law shows hot resistances as follows: 6v 0.115A bulb 52 ohms, 6v 0.15A bulb 40 ohms.
So why not try the 6V 0.15A bulbs and add a 12 ohm resistor in series with each to make up the difference. The rest of the circuit won't notice the difference. The bulbs might be a tiny bit dimmer than the originals, but not much. Worth trying? -Jeremy
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Jeremy, G8MLK, BVWTVM Friend, VMARS, BVWS Secretary. www.pamphonic.co.uk www.bttt.org.uk |
19th May 2022, 12:43 pm | #3 |
Diode
Join Date: May 2022
Location: Bude, North Cornwall, UK.
Posts: 2
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Re: Bush VHF71. My first restoration!
Hi, thanks, this was what I was thinking! Regards.
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