====== Receiver R1155 ====== Developed by [[Marconi]] on behalf of the Air Ministry. Manufactured by [[Marconi]] and E.K.Cole Ltd., also manufactured under contract by [[Plessey]], Mullard and E.M.I. In 1939, Marconi was commissioned by the British Air Ministry to develop a modern shortwave system to replace the T1083/R1082 and T1115/R1116 shortwave communication systems, some of which were already outdated. The combination of receiver R1155 with direction finding adapter and transmitter T1154 subsequently became the standard communication system in the Halifax and Avro Lancaster bombers during the war years and was also used in ground stations.\\ The development was carried out by Marconi and E.K.Cole Ltd., production was later outsourced to Plessey, Mullard and E.M.I. under the supervision of Marconi. {{:images:mil-uk-r1155.jpg?600|Air Ministry R1155}} ===== Technical data ===== * [[Principle]]: [[single conversion superhet]], [[IF]] 560 kHz * [[Operation modes]]: [[A1|CW (A1)]], [[A3|AM (A3)]] * [[Frequency range]]: 75 kHz - 18.5 MHz * [[Frequency display]]: [[analogue dial]] * [[Frequency memory]]: none * [[Signal strength indicator]]: [[magic eye]] * [[Signal processing]]: * [[Features]]: Connections for direction finder with homing function * [[Sensitivity]]: [[A3|AM (A3)]] / [[Selectivity]]: kHz (-6/-60 dB) ==== Power supply ==== * In the aircraft from the on-board power supply by means of a power supply with rotating converters for heater and anode voltage * Heater voltage 6.3 V, 4.0 Amp; anode voltage 220 V, 75 mAmp. ==== Dimensions ==== * 417 x 290 x 239 mm, weight 11.8 kg ==== Accessories ==== * Power supply unit with rotary converters for heating and plate voltage * Mains power supply unit Power Unit 114 or Power Unit 115 ---- {{:images:mil-uk-r1155-front.jpg?600|Air Ministry R1155}} ===== Operation ===== The R1155 receiver is usually installed together with the T1154 transmitter. The receiver measures 41.7 x 29 x 23.9 cm in its black sheet aluminium cabinet and weighs 11.8 kg; the R1155N variant for use in ground stations and Navy installations had a sheet steel housing. The colour-coded semi-circular frequency dial is located in the middle of the front panel, with the bandrange switch, also marked with coloured dots, in the bottom left-hand corner. The coloured dots correspond to the colours of the corresponding areas of the T1154 transmitter; areas not covered by the transmitter are marked with black dots. The R1155A (aluminium, used in the Halifax) and R1155F (aluminium, bombers other than the Halifax) versions of the receiver cover the long waves 75 - 200 kHz, 200-500 kHz, 600 kHz-1.5 MHz, 3-7.5 MHz and 7.5-18.5 MHz. The marine version R1155N (steel: non-flying use, ground stations, coast guard), R1155L (identical frequency coverage as N version, but aluminium cabinet for use on board aircraft) does not cover the long wave, instead there is an additional short wave range covering the 1.5-3 MHz maritime band. The volume control is located to the left of the frequency dial, the operating switch to the right. In the left position of the operating switch, the set is ready to receive radio transmissions, the AVC is switched off, the RF and IF gain is set manually with the "Increase Volume" control, in the next position the automatic gain control A.V.C. is activated and the "Increase Volume" control regulates the volume. The BALANCE position is used to adjust the balance of the two display needles of the direction indicator, in the VISUAL position the receiver with activated A.V.C. is ready to control the instrument with the direction indicator. In the position with the "infinite" symbol, the horizontal 8, the AVC is switched off, the bearing can be recorded acoustically and the side determination "L" / "R" can be carried out using the "AURAL SENSE" switch. In the top row of controls, on the left, there are controls for the levels for the left/right indicator of the navigation / homing system and at the right the magic eye serving as field strength indicator, then switches for the measuring range and for side determining using the direction finding antenna. The switch for the [[BFO]] for receiving [[CW]] and [[SSB]] transmissions is located at the bottom left of the front panel, to the left of the bandrange switch. The manual, which can be downloaded from the VMARS website, provides information on the function of the direction finding system: the two display needles of the R/L instrument are controlled alternately, one needle shows the voltage difference of the main antenna + frame antenna and the other main antenna - frame antenna, both needles meet in the centre line as long as the course is maintained at a right angle to the frame antenna. For directional flight, the operator sets the frequency of a known transmitter, as long as both needles of the display instrument meet on the vertical white centre line, the pilot maintains the course exactly to the set transmitter. If the crossing point deviates to the side, this indicates that a course correction is necessary. The multi-pin connectors for the various connections to and from the receiver are located in the bottom right-hand corner. The left-hand connector leads to the frame aerial, the centre connector is used to connect to the R/L dual needle display unit and the right-hand connector is used to connect to the main aerial, the transmitter and the operator's headset. On board aircraft, the power supply was provided by a power supply unit with rotary converters to supply the heating and anode voltages for the R1155 receiver, while a second converter supplied the anode voltage for the T1154 transmitter. On land, the set could be supplied with the necessary heating and anode voltages using power supply unit 114 or, if necessary, power unit 115. ===== Technical principle ===== Single conversion superhet ==== Components ==== The set is equipped with tubes. ===== Technical documentation ===== ==== Development ==== {{gallery>:images?mil-uk-r1155*.jpg&0&80x80&lightbox&showtitle&titlesort}} ==== Further information ==== * [[https://www.radiomuseum.org/r/unknown_r_1155.html|R1155 on the website of www.radiomuseum.org]]