[amsat-bb] Re: My first contact - almost

Gordon JC Pearce gordonjcp at gjcp.net
Tue Jun 16 01:19:59 PDT 2009

On Mon, 2009-06-15 at 23:07 +0000, kd8bxp at aol.com wrote:
> Well thanks to everyone who gave me helpful hints and ideas 
> I did almost make a contact today!

Well done!  Good fun, isn't it? ;-)

> I know I got into the SO50 today at about 11:10 - 11:11 est (local time) I heard some one give my call back and a brief report
> Unfortuntally at the same time doppler shifted on me and I wasn't fast
> enough to keep up
> I am using a th-d7ag and unfortunally there is not a way to program
> the odd band split in memory (at least not that I have found) so no
> matter what you have to hit two buttons. Anyways I diegress 

I wouldn't be hugely surprised if the TH-D7 is similar to the TH-F7
which I use.  I got into a technique of flipping between A and B to
transmit or tune Doppler.  In the higher parts of the pass the range is
changing relatively slowly and SO-50 should hang about more-or-less on
frequency for a good couple of minutes.

One of the mistakes I was making early on was not tuning far enough for
Doppler, and the other was changing too quickly.  It doesn't shift as
fast as you might think.  For the most part you won't have to worry
about Doppler on transmit, but on receive it makes a huge difference.
Well actually - on VHF you don't have to worry, on UHF it makes a
difference.  If you're using the ISS crossband repeater, that has its
input on UHF and then you leave the receiver alone and tune the
transmitter - much more fiddly because you *must* listen to the downlink
to get it right!

Headphones make all the difference, too - it's much easier to spot the
change in noise when you're on the satellite.  When it's transmitting
received noise, you can hear it has a distinctly different tone to
"empty sky".

Congratulations on your first contact on the satellites!

Gordon MM3YEQ (*still*, hurry up Ofcom)

More information about the AMSAT-BB mailing list