05-12-2017, 07:38 PM
(04-12-2017, 10:52 PM)Pat Pending Wrote: Unless there is some ant-farm magic going on I'm beginning to get a little bit suspicious of the 1Kw claim ...
Who would not like to see how they're managing the performance on so little grunt.
(05-12-2017, 07:21 AM)Crackle Wrote: I am certainly no expert on radio propagation, but I suspect the reason for the exceptionally good signal that many are getting up and down the country is because of the location of the transmitter, which is ... at Orford Ness, ...
The land all around is very flat and it has very close proximity to the sea, which makes the best ground plane possible ...
Here's an interesting comparison: I don't know how high the 648kHz antenna at Orford Ness is but the mv Caroline's mast rose 168ft - ~51m - above the deck. Caroline's transmitter power was 10kW (there were, in fact, two 10kW transmitters on board but they could only be operated one at a time).
The current Caroline power of 1kW is ERP. For comparison purposes, anybody got any idea what the mv Caroline's ERP was? I assume that the mv Mi Amigo, also 10kW from a 165ft (~50m) mast would have performed similarly. Also, I was once told by the chief radio engineer, Carl Thompson, on the Mi Amigo that the tide affected the signal level into London by three S points, depending on the ship's alignment. What this means in dB I haven't a clue, but it sounds rather a lot to me!
Nevertheless, both ships covered a lot of their respective ends of the country with 10kW after the Caroline/Atlanta merger so is it so surprising that 1kW over a relatively flat landscape can cover so well? No ant-farm magic required!
