UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Lancaster Bomber Radio signals and communications.

M0FYA Andy · 13th Jul 2018, 9:54 am

One thing which surprises me is how few of these documents even acknowledge the existence of the 'pilot's R/T set', (or Command Set in American parlance), let alone describe its operation. I just read through my copy of the Lancaster 'Pilot's Notes' and found nothing!

I've also been reading the AP for the A1134 Intercom Amplifier, and trying to distil the functionality of the key-switch, as opposed to which contact is fed to which transformer etc. and conclude the following -

The Intercom Amplifier has a three-way key-switch, with positions A, B and C. The normal position is B.
In position A the output of the R1155 is switched to the WOp’s headphones only, and his microphone and headphones are isolated from the Intercom circuit. The rest of the crew remain connected to the Intercom.
In position B, the WOp is also connected to the Intercom, and the output of the R1155 can be heard by all the crewmembers.
In position C all speech on the Intercom is connected to the T1154 transmitter.

Note that this has no effect on the pilot's R/T set, however it would allow the pilot to communicate with the airfield using the T1154 in the event of failure of his set. Obviously the WOp would have to tune his T1154/R1154 to the tower frequency and put the key-switch to position C.

13th Jul 2018, 9:54 am	#47
M0FYA Andy Nonode Join Date: May 2007 Location: Preston, Lancashire, UK. Posts: 2,511	Re: Lancaster Bomber Radio signals and communications. One thing which surprises me is how few of these documents even acknowledge the existence of the 'pilot's R/T set', (or Command Set in American parlance), let alone describe its operation. I just read through my copy of the Lancaster 'Pilot's Notes' and found nothing! I've also been reading the AP for the A1134 Intercom Amplifier, and trying to distil the functionality of the key-switch, as opposed to which contact is fed to which transformer etc. and conclude the following - The Intercom Amplifier has a three-way key-switch, with positions A, B and C. The normal position is B. In position A the output of the R1155 is switched to the WOp’s headphones only, and his microphone and headphones are isolated from the Intercom circuit. The rest of the crew remain connected to the Intercom. In position B, the WOp is also connected to the Intercom, and the output of the R1155 can be heard by all the crewmembers. In position C all speech on the Intercom is connected to the T1154 transmitter. Note that this has no effect on the pilot's R/T set, however it would allow the pilot to communicate with the airfield using the T1154 in the event of failure of his set. Obviously the WOp would have to tune his T1154/R1154 to the tower frequency and put the key-switch to position C.