Thanks to Jon VE1FTL I have the following interesting details on the system
at CFH. Jon says it is a Canadian Naval site and gives the location as
Newport Corner.
The transmitter is aging valve unit, capable of 25KW, but more usually run
at 8 to 9 kW.
Modulation is FSK +/- 42.5Hz from the nominal carrier. This power
corresponds to 30 to 40 Amps into the aerial, which is what I think would be
called an 'umberella' . The main radiator is about 600 feet tall (Jon hadn't
the exact dimensions to hand) It is capacitively loaded with a system
consisting of the top 25% of each of the six guy spans with the ends
connected together by a circle of wire, and then 6 more wires running from
the top to the this circular wire. Sounds a bit like the big brother of the
systems Dick was modelling a few weeks back.
The station is off the air for maintenance and will not return until the
Navy requests it. The transmitter is to be replaced by a more modern
solid-state class C unit some time early next year.
I guess there is enough detail there for some of you guys to estimate the
ERP. Ok we dont know what the losses are but I reckon we could make a
reasonable guess.
The plus point on this is that the aerial is about what I had though it
might be, but the power is a lot less (I thought it might be a 50kW unit) so
the margin needed to hear a amateur signal might not be so great. Of course
the 'answer's in the soil' !!
Once again this is all thanks to Jon, ( who is a technician on the site )
who has promised to e-mail me when it is due to return to the air.
73 de Alan G3NYK
[email protected]
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