Bush AC34 tuning lamps - UK Vintage Radio Repair and Restoration Discussion Forum

Gulliver · 12th Dec 2012, 2:38 pm

A couple of weeks ago I gave my Bush AC34 it's yearly dose of electrons, as it's not been in regular use since the 80's, and all is well. It took a few minutes to warm up (original caps believe it or not) but gave a lovely sound once it was running.

The only issue is the tuning lights have died.

can someone advise me what bulb I need? As with much of my vintage gear it's stored at my mother's house and I get few opportunities to tinker with it.

Photo attached, under all that dust is a lovely Bush logo.

richrussell · 12th Dec 2012, 3:17 pm

For the AC34 they should be 6.2V 0.3A bulbs.
For the DAC34 they should be 3.5V 0.15A bulbs.

ukcol · 12th Dec 2012, 4:19 pm

When you replace the bulbs replace the capacitor that couples the audio from the anode of the UBC41 to the grid of the UL41 output valve. If it is the original wax capacitor it will be leaky for sure and you run the risk of damaging the output valve and the output transformer.

The capacitor concerned is often referred to as "that capacitor" in these forums. In the case of the AC34 it is C26 in the Trader sheet and C33 in the manufacturer’s manual.

The other wax/paper capacitors will also be leaky but expensive damage is less likely.

Colin M

Gulliver · 21st Jun 2013, 8:37 pm

Could you point me in the direction of the trader sheet please.

Cobaltblue · 21st Jun 2013, 8:44 pm

Hi You can find the service information here

Nice set

Cheers

Mike T

60 oldjohn · 21st Jun 2013, 8:49 pm

Top right of this page "instant download" £1.99. helps fund the Forum.
Mike Has got there first.
John.

12th Dec 2012, 2:38 pm	#1
Gulliver Hexode Join Date: Aug 2011 Location: Luton, Bedfordshire, UK. Posts: 469	Bush AC34 tuning lamps A couple of weeks ago I gave my Bush AC34 it's yearly dose of electrons, as it's not been in regular use since the 80's, and all is well. It took a few minutes to warm up (original caps believe it or not) but gave a lovely sound once it was running. The only issue is the tuning lights have died. can someone advise me what bulb I need? As with much of my vintage gear it's stored at my mother's house and I get few opportunities to tinker with it. Photo attached, under all that dust is a lovely Bush logo. Attached Thumbnails

12th Dec 2012, 3:17 pm	#2
richrussell Heptode Join Date: Jul 2008 Location: Selby, North Yorkshire, UK. Posts: 979	Re: Bush AC34 tuning lamps For the AC34 they should be 6.2V 0.3A bulbs. For the DAC34 they should be 3.5V 0.15A bulbs.

12th Dec 2012, 4:19 pm	#3
ukcol Rest in Peace Join Date: May 2003 Location: Harlaxton, Lincolnshire, UK. Posts: 3,944	Re: Bush AC34 tuning lamps When you replace the bulbs replace the capacitor that couples the audio from the anode of the UBC41 to the grid of the UL41 output valve. If it is the original wax capacitor it will be leaky for sure and you run the risk of damaging the output valve and the output transformer. The capacitor concerned is often referred to as "that capacitor" in these forums. In the case of the AC34 it is C26 in the Trader sheet and C33 in the manufacturer’s manual. The other wax/paper capacitors will also be leaky but expensive damage is less likely. Colin M

21st Jun 2013, 8:37 pm	#4
Gulliver Hexode Join Date: Aug 2011 Location: Luton, Bedfordshire, UK. Posts: 469	Re: Bush AC34 tuning lamps Could you point me in the direction of the trader sheet please.

21st Jun 2013, 8:44 pm	#5
Cobaltblue Moderator Join Date: Dec 2010 Location: Exeter, Devon and Poole, Dorset UK. Posts: 6,876	Re: Bush AC34 tuning lamps Hi You can find the service information here Nice set Cheers Mike T __________________ Invisible airwaves crackle with life or at least they used to Mike T BVWS member. www.cossor.co.uk

21st Jun 2013, 8:49 pm	#6
60 oldjohn Dekatron Join Date: Dec 2004 Location: East Yorkshire, UK. Posts: 3,988	Re: Bush AC34 tuning lamps Top right of this page "instant download" £1.99. helps fund the Forum. Mike Has got there first. John.