Bush AC34 Valves - UK Vintage Radio Repair and Restoration Discussion Forum

Barneyuk · 23rd Sep 2009, 1:11 pm

Hi All,

I was led to believe that the valves required for the AC34 are the UCH42, UF41, UBC41, UL41 and UY41. However, after reading posts on here, UL84 is mentioned as required. Can someone please inform me if this is the case and if it is where? I have nowhere to put it! Could anyone also recommend me an alternative to the UF41?

Barney

Steve_P · 23rd Sep 2009, 2:20 pm

The manual is available up top there.

Valves are: UCH42, UF41, UBC41, UL41 and UY41.

Cheers,

Steve P.

Leon Crampin · 23rd Sep 2009, 3:29 pm

The UAF42 is a plug-in replacement for the UF41 as long as pins 3 & 4 on the socket are connected to pin 7. The Mullard data for the UF41 shows pins 3 & 4 as "IC" but every UF41 I have examined has these pins connected together internally anyway. Thus, by connecting these pins on the socket, either valve can be fitted at will.

The UL84 is often used as a replacement for the UL41 which is hard to get. It has a different (9 pin) base.

Leon.

paulsherwin · 23rd Sep 2009, 4:45 pm

There is usually no need to change all the valves in an old radio. In fact, the valves aren't responsible for most faults.

The most likely valve to be bad is the UL41 output valve. These are quite hard to find now, and consequently pricey. Some people modify sets to use a cheaper output valve such as a UL84, which may be where you've got the UL84 reference from: http://www.vintage-radio.com/recent-...bush-ac11.html

You should bear in mind that an unrestored AC34 is likely to need some capacitors changing at the very least if it is to work well. Changing the valves will make no difference to this, and the new output valve may have a short life if other faults aren't fixed.

Paul

Barneyuk · 23rd Sep 2009, 7:54 pm

Thanks all for the advice. I had 4 of the 5 valves but was a little unsure which was missing. I have now identified it was the UY41 missing but have a U142 in another set.

Now onto the capacitors!

Thanks

Barney

23rd Sep 2009, 1:11 pm	#1
Barneyuk Triode Join Date: May 2009 Location: Alton, East Hampshire, UK. Posts: 12	Bush AC34 Valves Hi All, I was led to believe that the valves required for the AC34 are the UCH42, UF41, UBC41, UL41 and UY41. However, after reading posts on here, UL84 is mentioned as required. Can someone please inform me if this is the case and if it is where? I have nowhere to put it! Could anyone also recommend me an alternative to the UF41? Barney

23rd Sep 2009, 2:20 pm	#2
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Bush AC34 Valves The manual is available up top there. Valves are: UCH42, UF41, UBC41, UL41 and UY41. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

23rd Sep 2009, 3:29 pm	#3
Leon Crampin Octode Join Date: Nov 2005 Location: Surrey, UK. Posts: 1,874	Re: Bush AC34 Valves The UAF42 is a plug-in replacement for the UF41 as long as pins 3 & 4 on the socket are connected to pin 7. The Mullard data for the UF41 shows pins 3 & 4 as "IC" but every UF41 I have examined has these pins connected together internally anyway. Thus, by connecting these pins on the socket, either valve can be fitted at will. The UL84 is often used as a replacement for the UL41 which is hard to get. It has a different (9 pin) base. Leon.

23rd Sep 2009, 4:45 pm	#4
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,967	Re: Bush AC34 Valves There is usually no need to change all the valves in an old radio. In fact, the valves aren't responsible for most faults. The most likely valve to be bad is the UL41 output valve. These are quite hard to find now, and consequently pricey. Some people modify sets to use a cheaper output valve such as a UL84, which may be where you've got the UL84 reference from: http://www.vintage-radio.com/recent-...bush-ac11.html You should bear in mind that an unrestored AC34 is likely to need some capacitors changing at the very least if it is to work well. Changing the valves will make no difference to this, and the new output valve may have a short life if other faults aren't fixed. Paul

23rd Sep 2009, 7:54 pm	#5
Barneyuk Triode Join Date: May 2009 Location: Alton, East Hampshire, UK. Posts: 12	Re: Bush AC34 Valves Thanks all for the advice. I had 4 of the 5 valves but was a little unsure which was missing. I have now identified it was the UY41 missing but have a U142 in another set. Now onto the capacitors! Thanks Barney