R. M. Radio
of Regent Square, London W C
1919 Founded by Henry R. Rivers-Moore
1920 ' A very interesting demonstration is to take place on board the Spanish steamer Suarez No. 1 in the Herculaneum Dock, Liverpool, today and to-morrow of the working of the wireless sets of the R. M. Radio, Ltd., which is a new wireless company formed last September, and which claims that the instruments of their system are an improvement on those at present in vogue on board ship and worked by the older firms of wireless telegraphy. These demonstrations on board the Spanish steamer named were commenced yesterday, and are being carried out by Captain De A. Donisthorpe, who is a director of the company, and, who has had a great deal to do with the inception and development of the R. M. Radio Co. The "R. M. R." set has been specially designed to met the requirements of ships having only limited space for radio equipment and requiring a transmitting range of about 200 miles, and is in accordance with the conditions laid down the International Radio-Telegraphic Convention and the Acts of Parliament relating to radio telegraphy. The transmitter and receiver are disposed in a handsome polished mahogany or teak cabinet, and form one complete unit. The apparatus is essentially simple, compact and easy to operate and maintain. It can be worked from the electric lighting supply of the vessel, but where none is available a separate engine dynamo can be supplied. The transmitter, which is of the spark type with a rotary discharger, can be operated on either 300 metres or 600 metres wave length by the movement of two switches, the change being thus effected in a few seconds. The receiver in the standard equipment comprises a tuner and crystal detector, and is suitable for reception of all wave lengths from 200 to 3.500 metres. It therefore covers the whole range of ship and here work, weather reports, time signals, direction finding signals and news service. A special design of crystal detector provides for the instantaneous replacement of a crystal which has become insensitive. If desired, a valve reception outfit, giving greatly increased receiving range, ran be included in the equipment at an extra cost. The change between transmitting and receiving conditions is effected by means of a pedal lever which controls all necessary switches and leaves the operator's hands free. The change is completed in about three seconds. In addition to the set described, demonstrations were also made on the emergency wireless net, where it was shown that while the aerials remained intact and undamaged and the wireless room remained above water the ship could transmit and receive Wireless messages, thus calling assistance to in case of disaster, or receive messages of help, which has been one of the greatest features of wireless telegraphy in the great war. A steamer which has been fitted with this new system of wireless telegraphy is the s. s. Isfeld, now on an expedition for the Northern Exploration Co., and which has been provided with a special long range apparatus, in order that during her absence in the Far North she ran keep in wireless communication with England and other countries. The Liverpool agents for the R. M. Radio. Ltd., are Messrs J. R. Fleming and Co., 327. Tower-building, Liverpool. with whom is associated Mr. G. Thorley, who will be pleased to give all information regarding the company'a system.'[1]
1922 'Mr H. Rivers Moore, managing director of R. M. Radio (Limited), states that, although he is the inventor at several patents owned by his firm, he is not the actual inventor of the R. M. Radio pocket-book wireless. The inventor is Mr. Donisthorpe, who was recently associated with him.' [2]
1923 R. M. Radio, Ltd., have temporarily moved their office to Garrick Street, W.C.2.[3]