A1134 info required - UK Vintage Radio Repair and Restoration Discussion Forum

Keith · 5th Jan 2006, 7:10 pm

Does anyone know where I could find a circuit diagram or other info on the A1134 intercom amplifier as used with the T1154? As I see little hope of acquiring the real thing I thought I might attempt a replica. Looking at pictures on the web it appears to use a single (pip top?) valve. This would tie up with the power requirements of 150V/2V DC. I'm guessing that it's a simple triode amplifier with transformer matching on i/p and o/p.

Thanks in advance,

Keith
G3XGW

Brased · 5th Jan 2006, 10:04 pm

I haven't got the circuit of either the A1134 or A1134A immediately to hand but the A1134A is certainly a little more complicated. Mine is fitted with two valves (120V HT and 2V LT) - VR21 (210LF) and VR35 (QP21) - so presumably it has a triode input with double pentode push-pull output.

The thing that looks like a pip top valve in the photo is actually the hinged cover which gives access to the two valves. The VR35 is on the left hand side. The spherical bulge in the cover allows for the extra height of this valve compared with the VR21. The 'pip' is the fastener for a short coil spring fixed inside the cover which secures the valve against vibration.

I could take some photos if it would help - PM me.

Edward

John H. · 24th Jan 2006, 6:35 am

Hi Keith,
Re your queries on the A1134 amplifier, I will be able to help you out with the circuit diagram and associated notes/component values etc for this but unfortunately I am away in Oz until end of March and all my files are in the UK. Edward is corect re the valve types and the power requirements.
The only difference between the amplifier A1134 and the A1134A is that the latter version has a low impedence output for headphones and the A1134 has high impedence output which was the earlier version.

Hope this is of assisance to you (but not immediately - sorry)

Regards, John H.

John H. · 7th Apr 2006, 6:22 pm

Message for Keith, G3XGW

Hi Keith.
Re your posting in January, do you still require the circuit diagram, components list and installation diagram for the RAF amplifier Type A1134, or are you now sorted. Am now back in UK so can onpass photocopies of these if still required.
John.

GMB · 7th Apr 2006, 8:37 pm

The complete manual is available from my Air Ministry equipment list

5th Jan 2006, 7:10 pm	#1
Keith Heptode Join Date: Jan 2003 Location: Tewkesbury, Gloucestershire, UK. Posts: 693	A1134 info required Does anyone know where I could find a circuit diagram or other info on the A1134 intercom amplifier as used with the T1154? As I see little hope of acquiring the real thing I thought I might attempt a replica. Looking at pictures on the web it appears to use a single (pip top?) valve. This would tie up with the power requirements of 150V/2V DC. I'm guessing that it's a simple triode amplifier with transformer matching on i/p and o/p. Thanks in advance, Keith G3XGW Attached Thumbnails

5th Jan 2006, 10:04 pm	#2
Brased Hexode Join Date: Mar 2005 Location: London, UK. Posts: 318	Re: A1134 info required I haven't got the circuit of either the A1134 or A1134A immediately to hand but the A1134A is certainly a little more complicated. Mine is fitted with two valves (120V HT and 2V LT) - VR21 (210LF) and VR35 (QP21) - so presumably it has a triode input with double pentode push-pull output. The thing that looks like a pip top valve in the photo is actually the hinged cover which gives access to the two valves. The VR35 is on the left hand side. The spherical bulge in the cover allows for the extra height of this valve compared with the VR21. The 'pip' is the fastener for a short coil spring fixed inside the cover which secures the valve against vibration. I could take some photos if it would help - PM me. Edward

24th Jan 2006, 6:35 am	#3
John H. Retired Dormant Member Join Date: Nov 2005 Location: West Sussex, UK. Posts: 51	Re: A1134 info required Hi Keith, Re your queries on the A1134 amplifier, I will be able to help you out with the circuit diagram and associated notes/component values etc for this but unfortunately I am away in Oz until end of March and all my files are in the UK. Edward is corect re the valve types and the power requirements. The only difference between the amplifier A1134 and the A1134A is that the latter version has a low impedence output for headphones and the A1134 has high impedence output which was the earlier version. Hope this is of assisance to you (but not immediately - sorry) Regards, John H.

7th Apr 2006, 6:22 pm	#4
John H. Retired Dormant Member Join Date: Nov 2005 Location: West Sussex, UK. Posts: 51	Re: A1134 info required - update Message for Keith, G3XGW Hi Keith. Re your posting in January, do you still require the circuit diagram, components list and installation diagram for the RAF amplifier Type A1134, or are you now sorted. Am now back in UK so can onpass photocopies of these if still required. John.

7th Apr 2006, 8:37 pm	#5
GMB Dekatron Join Date: Aug 2003 Location: near Reading (and sometimes Torquay) Posts: 3,094	Re: A1134 info required The complete manual is available from my Air Ministry equipment list