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Re: Re: More about QRM on AO-51 uplink



Hello Keith,

On Fri, Feb 25, 2005 at 08:46:54AM -0600, n6ors wrote:
> 
> 
> Francesco,
> Even FM has doppler shift, It is just not as noticable as on SSB because
> the descriminator (demodulator)
> tracks the signal and converts the frequency/phase  modulation to
> amplitude modulation. The Tone
> frequency is so low, 250hz or less, that the amount of frequency shift
> is on the order of millehertz. On
> 99.99% of the tone decoders this will make no difference.

well, I'd really need to re-read all formulae made at university time
to calculate it, but ok, it shouldn't be noticeable if the signal is beeing
demodulated correctly.
Anyway, to return on topic, I've never been able to work AO-51 with my setup,
while I worked one or more station in almost any pass I tried on UO-14 (good one),
SO-50, FO-20 and FO-29. 
On AO-51 I also tried with two different tone encoders (the internal one of the
TH-D7E and a self-made one with 8 bit/256 samples DDS generation), both work
flawlessy on SO-50 even with only 5W to a 4 element yagi.

73

Francesco	IZ5DWF
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