21st Aug 2013, 1:34 pm | #1 |
Retired Dormant Member
Join Date: Apr 2012
Location: Leeds, West Yorkshire, UK.
Posts: 33
|
Bush BA51
Just started working on this set.
Seems in pretty good order from first appearences apart from the speaker and output transformer. Both are in a sorry state. The cone is torn and deformed and it pretty much beyond repair. The transformer is open circuit. I suspect that the output valve will also need replacing as well. Any ideas where I can find replacements or workaround substitutes will be greatly appreciated as well as any experience of working on these Speaker is 8" 2.5 Ohm Valve is PM22A |
21st Aug 2013, 2:47 pm | #2 |
Retired Dormant Member
Join Date: Apr 2012
Location: Leeds, West Yorkshire, UK.
Posts: 33
|
Re: Bush BA51
Would a modern transformer like RS 210-6475 do the trick and would this give me more options regarding the speaker replacement?
Would prefer to put in authentic looking components but parts aren't easy to find. |
21st Aug 2013, 4:11 pm | #3 |
Octode
Join Date: Aug 2003
Location: Welwyn Garden City, Herts. UK.
Posts: 1,906
|
Re: Bush BA51
Yes that transformer would be OK
The speaker was likely to have been 3 ohms and the RL of the PM22A valve is 15K ohms. |
23rd Aug 2013, 11:41 am | #4 |
Retired Dormant Member
Join Date: Apr 2012
Location: Leeds, West Yorkshire, UK.
Posts: 33
|
Re: Bush BA51
using that transformer what sort of modern speaker would you recommend going for?
I presume that it wont be too fussy? The set was designed to allow an extension speaker to be run alongside or without the internal one so was designed to take a range of speaker setups? Wasn't expecting the speaker to be damaged. It doesn't look like its ever been removed and the speaker cloth was undamaged. Yet the speaker was torn and bashed about no end. Thanks |
23rd Aug 2013, 12:12 pm | #5 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,526
|
Re: Bush BA51
With the ratios offered by the RS transformer, pretty much any speaker 3/4/8/15 ohms that will fit will be fine electrically. Perhaps cannibalizing a tatty valve portable o/p TX would be cheaper, though, in which case 3-4 ohms would be best.
It shouldn't be too difficult to source a second hand more appropriate looking speaker, they were standard radiogram fodder......
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