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Re: P3D information

on 10/10/00 10:03 PM, Dan Schultz at n8fgv@AMSAT.Org wrote:

> P3D supports both modes, and Mode B will probably get
> the lion's share of the operating time in the first year.

Who knows.  The first year will be mainly putting the satellite into orbit.
Mode B will probably be the only thing available, but at low power and
sporadic times at best.

> But when all
> the new hams see how easy it is to operate on the microwave bands, the
> demand for transponder time will increase and eventually the pendulum
> will shift to the point that the microwave modes will get most of the
> operating time.

Perhaps. But there are a lot about the microwave bands that we do not know
yet since we've never had a bird with greater than an S band downlink.  What
will doppler shift or antenna pointing be like on 10 GHz?  Will we have rain
scatter problems, etc, etc.  All cool and fun stuff to find out, but these
bands are a question as to their "ease."  There is also the cost.  Not only
do you have to buy the "IF rig" but all the transverters as well.
Microwaves are much more costly.

> By the time we are ready to build P3D's successor
> satellite, the mode B antennas will be rusting away like the C band TVRO
> dishes. At least those can be used to make a bird bath.....

First of all, my mode B antennas are made out of aluminum.  I've never seen
iron oxide (rust) form on aluminum.

Second, C band TVRO dishes are not at all rusting away.  To the contrary, if
I was going to have a dish, I'd much rather have a C band than DSS.  My
future father in law has a C-band dish and it is awesome.  It moves to
change birds, there are more channels than you can shake a stick at, network
feeds, music feeds, etc.  Oh yes, and many of the signals are digital as
well nowadays.  DSS is nothing more than CATV delivered via 12 GHz from
overhead.  C band is far better if you really want programming flexibility
and choices.  Those who are that much into TV and videos always choose the
C-band dishes.  I don't see many rusting.

Also, if DSS and small dishes are so good, then why aren't TV networks and
broadcast stations flocking to use them?  Because they aren't good



Jon Ogden
NA9D (ex: KE9NA)



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

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