The Sumburgh Head radar facility started permanent watch on 27th December 1939. The station was tasked with plotting surfaced U-boats attempting to escape from the North Sea into the North Atlantic, but was also capable of detecting aircraft. As the science and practice of radar evolved through the late 1930’s, Sir James Somerville, Vice Admiral of the Royal Navy, proposed a wider network of naval stations to protect the strategically significant waters to the north of Scotland. This included stations at Dunnet Head, South Ronaldsay, Fair Isle, Unst, and later, on the north-west coast of Iceland.
Construction of the Sumburgh Head radar station began in October 1939. The receiver hut was placed just outside the southern wall of the inner enclosure of the Sumburgh Head Lighthouse buildings, whilst the transmitter hut was erected immediately adjacent to the foghorn. Both structures still survive, with the transmitter hut having been restored to re-create how it might have appeared in 1940 – with a little bit of artistic licence. Having both transmitter and recieving stations in one building allows visitors to see the complete operation.
The original huts were made of wood but were soon replaced with a more substantial shuttered concrete design. The huts were straddled by gantries which carried the aerial arrays, one for transmitting, the other receiving. Inverted searchlight turntables were used for rotation, which was carried out manually using a chain connected to an up-turned bicycle framework – with the pedals replaced by wooden handles for turning! This set-up can be seen in the re-created radar hut.
Mark G0MGX made some investigation into this suggestion which resulted in the graph below –
Mark then went on to compare the IC7100 with a Kenwood TS990 by measurement of the TS990 sensitivity on 6 metres, as shown on the following graoh –
The person who originally posted the question made the observation that the IC7100 reception on 4 metres appeared to benefit from the insertion of a pre-amplifier.
From February 2 to September 31 2015, the special callsign YP10EURAO will be aired, mainly at weekends, to celebrate the 10th anniversary of the formation of the European Radio Amateurs’ Organisation EURAO.
YP10EURAO is put on air by the Asociatia Radioclubul României, YO9KYO, a associate member society of EURAO.
In this talk from the Charlotte Hamfest, Roland Kraatz W9HPX presents the research he’s done on D-STAR, DMR and Fusion. No on-the-air comparisons This is a slide show that compares operational capability and some tech specs.
We’re a few weeks away from Yaesu’s North America release of WIRES-X, the Internet linking system for Fusion, so Roland only has a few details on that based on manuals.
Here are links to some of the resources Roland talks about:
http://charlottedstar.org/ – The Charlotte Digital Radio Groups site
http://charlottedstar.org/Comparison%… – Roland’s slide show PDF
http://www.trinityos.com/HAM/Yaesu-Sy… – KI4ZD’s slide show on Fusion