[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

U/V vs. microwaves



Tony Langdon wrote:

Hmm, for me, V/U is _much_ more expensive than something like C/X?  Why?
Becuase I don't already have V/U gear, and V/U requires a lot more in the
way of space and mounting hardware than a couple of home brew converters.

Wayne replies:

C/X and U/V antennas can both be homebrewed very cheaply.  But I can hardly
imagine how C/X radio equipment could be cheaper than U/V equipment because
a C/X satellite setup will still need two SSB/CW IF radios (unless you're
talking about some future TDMA digital mode).

The total cost of two SSB/CW IF radios, plus a bunch of converters, plus a
microwave power amplifier is likely to be higher than the cost of a U/V
satellite radio.  I suppose a C/X station could use two cheap CB/10m SSB IF
radios, with perhaps 3 stages of converters on both the uplink and downlink.
But that claptrap would be very finicky to actually use and make contacts.

V-band or higher IF radios are more practical to minimize the number of
conversion stages and/or simplify the filtering.  You might as well use V
and U bands for the IF radios.  And if you do that, a U/V "satellite" radio
will make the operation MUCH more practical because of tracking VFOs and a
serial port for computer-controlled Doppler tuning (Doppler is not trivial
at 10 GHz).  A U/V satellite radio is really the best IF "foundation" for a
microwave satellite station.  And it just happens to give you the ability to
operate mode U/V and V/U should you ever need to operate in a location with
lots of trees (and find a way to put up U/V antennas).

Microwave fanatics boast about how small the antennas are.  They must all
live in deserts or brand-new subdivisions that have no trees.  Or have a
tall tower to get those tiny antennas above the trees.  We really need BOTH
microwaves and U/V to meet the needs of most satellite enthusiasts.  Those
with antenna restrictions will prefer microwaves.  Those with tree
restrictions will prefer U/V.  A lot of us want both microwaves and U/V.

Wayne Estes W9AE
Mundelein, IL, USA


----
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home