Ian Ropper GM0UHC drew an attendance of 24 for his talk on 27th April on the restoration of the classic Marconi WWII RAF R1155 Receiver & T1154 Transmitter as used in the Lancaster bomber and other aircraft. Visitors from the Livingston & District Amateur Radio Society and from the Museum of Communication in Burntisland were particularly welcome.
Ian described the problems in restoring this equipment, now about 70 years old: the rubber insulation on connecting wires just cracks off; electrolytic capacitors have dried out; resistors are unreliable. The equipment must be stripped down to the plain chassis, complicated by the fact that the various parts of it were spot-welded rather than bolted together. Lettering on the front panels just flaked off when cleaning was attempted, requiring re-painting and re-lettering. Ian installed modern electrolytic capacitors inside the cans of the now-unobtainable original capacitors to preserve the appearance of the equipment, and all the resistors were replaced. Parts such as the PT15 pentode PA valves were purchased via E-Bay.
Ian demonstrated his working equipment which generated much interest from the crowd.
Ian's website will shortly have a section on his T1154 restoration, in addition to his existing pages on Racal RA17 / RA117 restoration: http://www.chavfreezone.me.uk/
Photographs by Ian Ropper GM0UHC, Peter Dick GM4DTH and Alan Masson GM3PSP:
Ian Ropper GM0UHC
The excellent attendance of 24 filled the room.
The working equipment demonstration. In addition to the R1155 and T1154 (centre),
Ian also showed the dummy load (left) and his home-built power supply (right).
In the aircraft, power was provided via dynamotors.
Schematic of the entire system in a Lancaster bomber.
One enthusiast built an entire Lancaster mock-up in his attic.
Ian's R1155 and T1154 equipment.
Ian's R1155 receiver is identified as an AD8882B, possibly a prototype.
Front of Ian's T1154 transmitter.
Melvyn GM4HYR and Mike GM8KCS examine Ian's restored T1154 out of its case.
Ian GM0UHC takes questions after his talk.