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Working LEO Satellites




I have been reading a few messages about working Low Earth Orbit
satellites, and the comments about UO-14 are correct even down under.

I work Voice on UO-14 on FM, FO-20/29 on SSB and also RS12/13 on what
ever mode it is using at the time. AO-10 at times and also PCSAT and ISS
for APRS. I also work AO-40.

My gear is not high tech just an old Kenwood TR9130 and an Icom-490A
into a 20 El Crossed yagi on 2M and 16 EL vert/pol Yagi for 70cm.
No pre-amps for 2M or 70cm
But I do use a AZ/EL rotator system G-1000S and G500A. This is
interfaced via a EA4TX designed controller and software that drives my
set-up automatically while I do the talking.

UO-14 is used regularly by about  4  ZL stations and is well patronized
by several VK stations that I have regular contact with. Many of these
stations have had similar problems with their downlinks. But after some
tuition they have had great success on UO-14.

The biggest confusion has been that stations chase both the uplink and
downlink frequency when they only need to follow the doppler on the
downlink.
STAY on 145.975 FM uplink and then listen when it first comes over the
horizon at  435.080 FM. The squelch needs to be almost open but not
quite so that when you are able to make contact the squelch will open on
its own. The squelch will close again when your downlink is lost.
This will last for about a minute or maybe two, and then you will need
to change frequency to 435.075 then to 435.070 then 435.065 and then
435.060 and finally 435.055.
I can assure you that 95% of the time you are making it into the
satellite but its your downlink that is the problem.

I have several ham friends in VK land that use 500mw and max 5W on HTs
and using this method have no problems making contact on UO-14 for most
of the path..
Another hint is to point the tip of your HT antenna at the ground as you
follow the satellites path at about a 35° to 45° angle or over your
shoulder. DO NOT POINT  THE TIP AT SATELLITE.

Try it I'm sure you will have a lot more success and maybe more interest
in LEO sats if they go FM.

73's Sonny ZL1HAU

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