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Re: AO-40 status report by DJ4ZC

No, Phil, you are incorrect.

You of all people should complain that the 70 cm downlink might be damaged!
Wasn't it you who wanted to do away with 70cm and 2m all together?  I could
find your quote on that......

Fact is, you'd probably be happiest if both 70 cm and 2m were damaged.  That
way, you'd get your wish to eliminate mode B and mode J.

The fact is that mode U/V is likely the mode that will be predominately
used.  Most people are set up for this mode.

The fact is that S-band works and works well according to the control team.
So for those who have two meter reception problems, S band is certainly a
good option and one that you certainly favor.


on 11/21/00 8:20 PM, Phil Karn at karn@qualcomm.com wrote:

>> Well, if there was a transmitter that I would prefer to fail it would be the
>> 70cm transmitter!  Mode U/V has long been considered the "primary" mode of
> Tell that to the Japanese, for whom severe terrestrial interference
> makes the 2m band nearly useless as a satellite downlink.  Or to those
> of us unfortunate enough to live near large power lines emitting
> significant noise power on the 2m band.
> Naturally I would prefer that *everything* on P3D work, but given a
> choice between 2m and 70cm, 70cm is clearly far more important.
> If you assume the use of simple, semi-omnidirectional ground antennas
> (e.g., patches) and take into account path loss and background noise
> levels, 70cm is clearly the optimum downlink frequency for an amateur
> satellite. 2m is just too noisy and crowded. 13cm is far better, but
> it requires a ground antenna with at least some directionality.

Jon Ogden
NA9D (ex: KE9NA)



"A life lived in fear is a life half lived."

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