There were 10 production versions of the R1155, being the R1155, R1155A, R1155B, R1155C, R1155D, R1155E, R1155F, R1155L, R1155M and R1154N. The major differences are the the chassis and case construction material and the different frequency ranges between the versions (see below).
Purpose of equipment:
Designed for use in aircraft with transmitters of the T1154 class. Also used in some air-sea rescue launches (the R1154N and R1155L variant), radio vehicles and ground installations Provides communication and direction-finding facilities. Receives R/T, CW and MCW.
R1155, R1155A, R1155B, R1155C,
R1155D, R1155E, R1155F, R1155M: 75 - 500 kHz (2 bands), 600 - 1500 kHz, 3.0 - 18.5 MHz( 2 bands).
R1154L, R1155N: 200 - 500 kHz, 0.6 - 18.5 MHz (4 bands).
Input of 10uV at 210 kHz gives output in excess of 50 milliwatts. Input of 9uV at 16 MHz gives an equivalent output.
Approximately 4 kHz to 6 kHz total bandwidth for 6 dB attenuation.
Visual D/F switching - two triode hexodes - VR99A
RF Amplifier - variable-mu pentode - VR100
Frequency changer - triode hexode - VR99
IF amplifier - two variable mu pentodes - VR100
AVC and BFO - double diode triode - VR101
Speech diode, visual meterlimiter and output - double diode triode - VR101
Visual meter switching - double tride - VR102
Tuning indicator - VR103
Omni and AVC - approx 45W
Visual DF - approx 50W
Max 200mW into 5000 Ohms impedance.
16 7/8" long, 9 3/8" wide, 11 3/8" high.
Aluminium versions - approx 26lb.
Steel versions - approx 32lb.
T1154 series transmitters, Resistance Units Types 47, 52 and 52A, Aerial Switch Unit Type J, Visual Indicator Type 1, Impedance Matching Units Types 12, 13 0r 15, Power Units Type 32, 32A, 32B, 33, 33A, 33B, 34, 34A, 35 and 35A, ground Power Units type 114, 115, 268 and 380.
Typical aircraft installation:
In aircraft the receiver would normally be mounted underneath or alongside the T1154, and would be fitted in a convenient position for the operator, where possible at desk level. The receiver would normally be mounted horizontally using mountings type 54, however where space is limited it can be mounted vertically with a sponge rubber pad (mounting type 55) between the table and the bottom of the Rx. The receiver is not fitted with internal illumination, and would be positioned where natural illumination is good. The receiver shares the transmitter HT and LT power units, the latter supplying the receiver.
In certain aircraft, a second R1155 would be fitted for exclusive use by the navigator for direction finding purposes. The DF facility is facilitated by a fixed sense aerial, and a Loop Aerial Type 1 (with Impedance Matching Unit Type 12), Loop Aerial Type 3 or a Bendix Loop Aerial (with Impedance Matching Unit Type 15). Hampden aircraft used a retractable loop aerial with Impedance Matching Unit Type 13. Where a second receiver is fitted, the visual indicator is moved from the W/T operator's position to the navigator's position.
There was a broadcast radio station called Radio Athlone which transmitted on the R1155 IF frequency, causing breakthrough in some instances. To prevent this a filter was produced, called the 'Athlone Filter'.
The following description is from John Gibson - thanks John.
The filter came about because the R1155 IF frequency is the same as that of Radio Athlone, a powerful Republic of Ireland national transmitter, and a RAF aircraft flying over N. Europe would receive a whopping signal which would cause IF breakthrough in a radio with an IF of 560 kcs. The R1155 is a compactly built radio as anyone who has had to replace bits will testify, so the filters had to be shoehorned in. If you follow the lead from the top cap grid of the RF valve it will go into a cylindrical can with a lid, perched on top of another cylindrical coil can on top of the chassis. This is the first parallel reject filter. If you go under the chassis, you will find the RF valve plate lead going to two places. One is a series accept filter to ground, the other is a parallel reject filter between the second RF transformer and the RF valve plate. All these filters are tuned to 560 kcs. Probably overkill but it worked.
More R1155 pics are here
For other installation details. see the description for the T1154 here.
Typical high speed launch installation
This is covered under the description on the additional page, here.
I'd like to know more about which aircraft the 1154/55 were used in. Please drop me an email if you can add to the list. So far I understand they were fitted in the Lancaster, Halifax, Hampden, Sunderland, Anson, Lincoln, Lancastrian, York, Varsity, Stirling, Mosquito, Proctor, Prentice, Hastings, Briggand, Valetta, Shackleton (1951 to 1965), Manchester, Warwick, Albemarle, Botha, Wellington IC, II, III IV & V, Whitley V, Beaufighter, Blenheim IV, Beaufort, Dominie.....
Alan Morriss, G4GEN, emailed to say... 'They were used post war in civil aircraft usually with the Packard Bell pre amp for audio. However most usage was in CW mode. We had them in Air Charter and British United Airways, which it was incorporated into. They were fitted in Bristol Freighters when we went on a charter where HF was needed. They were modified for crystal control using the proper replacement unit.
Oh - and the NDB at Halfpenny Green (Bobbington) airfield was a T1154 in 1972...
Thanks to those of you who have emailed me with additions to the list.
Are there any more aircraft (or installations) which you know of ?
To the T1154 page
Inter-Unit Cabling Diagram
More 1154/55 stuff...
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