Joan-Eleanor system

The Joan-Eleanor system (or J-E for short) was a very high frequency (VHF) radio system developed during World War II for use by agents working behind enemy lines to relay information and replaced the earlier S-Phone system used by agents.[1]

Design and development

The Joan-Eleanor system was developed from late 1942 onwards for the US Office of Strategic Services (OSS) by DeWitt R. Goddard and Lt. Cmdr. Stephen H. Simpson, with some contributions from mobile radio pioneer Alfred J. Gross. It was reportedly named for Goddard's wife's Eleanor, and a WAC Major of Simpson's acquaintance named Joan.[1]

The initial design work was performed at RCA's laboratories in Riverhead, NY, and the production units produced by Citizens Radio of Cleveland, Freed Radio Corporation of NYC, Dictagraph Corporation of New York, and the Signal-U Manufacturing Company. Most of the testing was carried out in the USA and some at Bovington, England, beginning in July 1944, to refine the equipment with the first operational use later that same year.

The system was classified as top secret by the US military and was not declassified until 1976.

Description

The system comprised a pair of transceivers:[2]

The system was designed to use the VHF band, since it was known that these frequencies could not be effectively monitored by the enemy. The agent made his report in plain speech, and the aircraft recorded the transmission on a wire recorder. Since Morse code was not required, the agent did not need to be trained in it, thus reducing overall training time, which was considered an advantage in the European theater. Additionally, the aircraft could ask for immediate clarification if required, without the delay of encryption and decryption, or an intelligence officer aboard the circling aircraft could talk directly with the agent.

Because of the low power and the unit's limited range, the transmissions were virtually undetectable and the Germans were unaware of the system.

SSTC-502 transceiver

Unlike large conventional radios that weighed up to 30 pounds, the hand-held SSTC-502 transceiver was only 6.5" long and weighed less than one pound.[2] It used a dual triode as a combination super-regenerative detector while receiving, and an oscillator during transmission. Two other vacuum tubes acted as a microphone amplifier and modulator. The antenna was a simple dipole attached to the top of the unit and the only controls were for regeneration and fine tuning. The unit was powered by two D cells for the tube filaments, and two 67.5 V batteries for the tubes' plates. The original operating frequency was 250 MHz, but it was discovered that the Germans had a receiver capable of operating at this frequency, and it was changed to 260 MHz.

SSTR-6 transceiver

The airborne SSTR-6 transceiver weighed about 40 pounds.[2] It had a superheterodyne receiver with two RF amplifier stages, two limiter stages, and an FM detector. Power was supplied by four 6V wet cell batteries. The equipment was used in B-17 and de Havilland Mosquito aircraft, the Mosquito being used for most missions due to its high speed and high altitude capability which rendered it safe from most defenses.

Operational

The initial aircraft used with the J-E system were de Havilland Mosquito PR (Photoreconnaissance) Mk. XVI aircraft of the 654th Bombardment Squadron, 25th Bomb Group Rcn at Watton, UK. Since 25th Bomb Group personnel flew Joan-Eleanor missions for OSS, Watton wished credit for these in monthly operational tabulations. They assigned the label Redstocking to the missions. For J-E missions the rear-fuselage compartment, aft of the bomb-bay, was fitted with an oxygen system and modified to accept the SSTR-6 transceiver and wire recorder, with an operator sitting on a cramped seat, and accessed through a side hatch.

The first successful operational use of the system was made on 22 November 1944 by Stephen H. Simpson; he recorded transmissions from an agent codenamed "Bobbie" while orbiting at 30,000 ft over the occupied Netherlands. Another occurred on 12/13 March 1945 when a Mosquito PR XVI at 25,500 ft near Berlin established radio contact with agents who had earlier been dropped on 1/2 March from an A-26 Invader.

On 13 March 1945, HQ 8th AF ordered the OSS JE Project transferred to the 492nd Bomb Group's Liberator base at Harrington, Northamptonshire. On this day the term Redstocking ceased to exist. On 14 March two Mosquitoes and an A-26 flew to Harrington followed on the 15th by other Mosquitoes and A-26s. The 25th BG aircrew flew the OSS Mosquito JE missions until 492nd men completed training on this aircraft type. Both Mosquito and A-26 remained stationed at Harrington, and on occasion a Mosquito flew to Watton for inspection. OSS JE project personnel at Harrington frequently consulted Watton. The 654th Bombardment Squadron flew 31 Joan-Eleanor (JE) missions from Watton on behalf of the OSS over the Netherlands and Germany, and an additional 31 JE missions from Harrington.

Notes

  1. 1 2 Bowman, Martin W. (1999). Mosquito Photo-Reconnaissance Units of World War 2. Osprey Publishing. p. 62. ISBN 1-85532-891-7.
  2. 1 2 3 Breuer, William B. (2000). Top Secret Tales of World War II. Wiley. pp. 207–208. ISBN 0-471-35382-5.

References

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