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Re: [HCDX] Diego Garcia kW
I guess Navy bases may use any transmitter available
at that moment to relay AFN. So we can never be sure
if the certain transmission is with "listed power" or maybe
more. Also Guam 5765 is some days real strong here.
Years ago (my QSL from 1998) HCJB (Quito) had a 500 W
USB transmitter on 21455 (with rhombic 35/225 degs) and
the signal was nice here in Finland. They still use some
SSB transmitters (I recall 1 and 25kW) but with reduced
carrier added to enable reception in AM mode. With reduced
carrier the formula to compare with AM, Matti gives, doesn't
work directly, I believe.
[HCDX] Diego Garcia kW
Hi Rob and all HCDX readers,
Huh, to begin with, sorry, a typo: 3000 W SSB equals about 12 kW AM of
course. I seem not to be very good at counting zeroes. Some kind of
reeeding disorder ? (hi)
AFN seems to have good equipment to push the signal around the globe. I
still think that the published 3000 W may be 30000 W in real life.
The carrier in AM takes about 50 per cent of the power, the one single side
band takes 25 and the the other takes 25 per cent. So, the required power
to create a SSB signal through the air is only a quarter compared to that of
an AM. With a decent bandwidth (in transmitter and receiver) and not too
much compression in transmitted audio, even music can be quite enjoyable.
Let's modify all the AM receivers in the world into SSB receivers...
73 de Matti Ponkamo, Naantali, Finland
> Date: Thu, 29 Dec 2005 18:01:09 +1100
> From: Rob Wise <rhwise@xxxxxxxxx>
> Subject: Re: [HCDX] Hard-Core-DX Digest, Vol 36, Issue 29
> To: hard-core-dx@xxxxxxxxxxxxxxxx
> Hoyo Matti,
> I think more organizations/ international broadcasters should use SSB
> as its less power. All the BBC do is talk all day, so why bother using
> Anyhow AFN seem to get around the globe on only a few watts so thats
> good news, and 120 KW AM seems like little distance.
> I find the AFN has over modulation issues with the Diego Darcia TX as
> the audio is a tad distorted (clipping).
> Rob Wise
> > Date: Wed, 28 Dec 2005 09:49:59 +0200
> > From: "Matti Ponkamo" <mattipo@xxxxxxxxxx>
> > Subject: Re: [HCDX] Diego Garcia kW
> > I recall that ILG says 3000 watts USB, and that equals about
> > 120 kW AM ?
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