Air Ministry Amplifier A.1368 - UK Vintage Radio Repair and Restoration Discussion Forum

Avro626 · 21st Aug 2007, 8:54 pm

Hi, I have just purchased an Air Ministry Radio Amplifier A.1368 and have very little information on it. I am led to believe it was used in Lancasters in conjunction with radios other than the T1154/R1155. Can anyone tell me any more about this item please?
Dave

Keith · 22nd Aug 2007, 10:52 pm

Dave,

From the photo it looks very much like a simplified version of the A1134, minus the three position switch. It still seemds to require 120V/2V battery supplies. Does it use the same QPP output stage I wonder?

Keith

GMB · 23rd Aug 2007, 8:57 am

I have not encountered this amplifier before but externally it looks identical to A1219 which was the multi-seat adaption for the TR1133 VHF set.

A photo of the insides may help further identify it.

Avro626 · 23rd Aug 2007, 10:28 pm

Hi, Thanks for the replies, I shall examine it a little closer and post some more pictures soon. Thanks once again guys. Regards Dave

Avro626 · 15th Sep 2007, 3:23 pm

Hi, I have now taken some photos of the inside of this A1368 Amplifier I have, it would be nice if anyone can throw any light on what it is, when and where it was used plus any further information on it. Thanks Dave

Keith · 16th Sep 2007, 3:36 pm

Dave,

As I suspected, internally it is very similar to the A1134 intercom amplifier as used on the Lancaster, etc but minus the complicated switching. It's basically a triode mic amplifier followed by a double pentode in "quiescent push-pull" (presumably for battery economy), all transformer coupled. There is some information here:

http://home2.btconnect.com/gmb/airequip.htm

Avro626 · 17th Sep 2007, 7:57 pm

Hi Keith, Many thanks for the info. Does anyone know where this Amp would have been used and what aircraft would it have been used in? Dave.

21st Aug 2007, 8:54 pm	#1
Avro626 Retired Dormant Member Join Date: Jun 2007 Location: Holmfirth, West Yorkshire, UK. Posts: 29	Air Ministry Amplifier A.1368 Hi, I have just purchased an Air Ministry Radio Amplifier A.1368 and have very little information on it. I am led to believe it was used in Lancasters in conjunction with radios other than the T1154/R1155. Can anyone tell me any more about this item please? Dave Attached Thumbnails

22nd Aug 2007, 10:52 pm	#2
Keith Heptode Join Date: Jan 2003 Location: Tewkesbury, Gloucestershire, UK. Posts: 693	Re: Air Ministry Amplifier A.1368 Dave, From the photo it looks very much like a simplified version of the A1134, minus the three position switch. It still seemds to require 120V/2V battery supplies. Does it use the same QPP output stage I wonder? Keith __________________ Keith Yates - G3XGW VMARS & BVWS member http://www.tibblestone.com/oldradios/Old_Radios.htm

23rd Aug 2007, 8:57 am	#3
GMB Dekatron Join Date: Aug 2003 Location: near Reading (and sometimes Torquay) Posts: 3,092	Re: Air Ministry Amplifier A.1368 I have not encountered this amplifier before but externally it looks identical to A1219 which was the multi-seat adaption for the TR1133 VHF set. A photo of the insides may help further identify it.

23rd Aug 2007, 10:28 pm	#4
Avro626 Retired Dormant Member Join Date: Jun 2007 Location: Holmfirth, West Yorkshire, UK. Posts: 29	Re: Air Ministry Amplifier A.1368 Hi, Thanks for the replies, I shall examine it a little closer and post some more pictures soon. Thanks once again guys. Regards Dave

15th Sep 2007, 3:23 pm	#5
Avro626 Retired Dormant Member Join Date: Jun 2007 Location: Holmfirth, West Yorkshire, UK. Posts: 29	Re: Air Ministry Amplifier A.1368 Hi, I have now taken some photos of the inside of this A1368 Amplifier I have, it would be nice if anyone can throw any light on what it is, when and where it was used plus any further information on it. Thanks Dave Attached Thumbnails

16th Sep 2007, 3:36 pm	#6
Keith Heptode Join Date: Jan 2003 Location: Tewkesbury, Gloucestershire, UK. Posts: 693	Re: Air Ministry Amplifier A.1368 Dave, As I suspected, internally it is very similar to the A1134 intercom amplifier as used on the Lancaster, etc but minus the complicated switching. It's basically a triode mic amplifier followed by a double pentode in "quiescent push-pull" (presumably for battery economy), all transformer coupled. There is some information here: http://home2.btconnect.com/gmb/airequip.htm __________________ Keith Yates - G3XGW VMARS & BVWS member http://www.tibblestone.com/oldradios/Old_Radios.htm

17th Sep 2007, 7:57 pm	#7
Avro626 Retired Dormant Member Join Date: Jun 2007 Location: Holmfirth, West Yorkshire, UK. Posts: 29	Re: Air Ministry Amplifier A.1368 Hi Keith, Many thanks for the info. Does anyone know where this Amp would have been used and what aircraft would it have been used in? Dave.