Dear LF Group,
I looked at several LF and MF broadcast carriers last night; some showed
carrier levels that increased in the quiet periods like Droitwich, others
increase the carrier level with increasing modulation like DLF, and some
just have a plain, steady carrier - from which I conclude there is no
consensus amongst broadcast engineers!
All this is very interesting, but it makes it more difficult to measure the
field strength - I suppose the thing to do is measure the carrier level
during a period of silence in the programme material, when the carrier
level is constant, at least for a second or two. Also, how does one
interpret the transmitter power of these stations? If Droitwich is 500kW,
is this carrier power, and if so under what conditions ("peak carrier
power" perhaps?) or PEP? - or mean power?
Cheers, Jim Moritz
73 de M0BMU
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