For longer-range communication, the T1087 transmitter, installed at Markstone Moss in Holm, sent messages in Morse code to aircraft of Bomber and Coastal Command.
The Museum has a map of the various wartime sites in Orkney – in fact it is an original map from the Fighter Sector Operations Room in Kirkwall. It shows all 88 heavy anti-aircraft guns that circled Scapa Flow to protect the Fleet.
There are many fascinating wartime documents, including a diary of service on the Arctic convoys sailing to Russia. There are also copies of the wartime forces newspaper, The Orkney Blast, with the printing block for its masthead.
There are indeed radios for every type of situation. The Wireless Set No. 19 was designed for use in the back of a lorry or jeep, with two separate transmitter/receivers, one for short range and one for long range, plus an intercom for use in a tank. There is a suitcase radio that was used by agents and partisans in France and all over Europe. And there is a German U-boat communications receiver and a Morse key from a German plane shot down in Orkney in 1939.