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Re: Tuning conundrum

on 12/16/99 3:35 PM, Peter A. Klein at pklein@2alpha.net wrote:

> What happens when working "split mode?"  Say we're on RS-13.  Operator #1
> is using Mode A (144 up, 29 down), and Operator #2 is using Mode K (21 up,
> 29 down).  I think that in this situation, Op #2 might do better to tune
> his 21 MHz uplink, even though it's lower. That way he won't constantly
> undo Op #1's tuning of 144 MHz.

Good point!

> I suspect we'll run into this more on P3D when multiple transponders are
> turned on.  And they probably will, for backward compatibility with current
> Phase III operators. Not everyone will invest in microwave installations
> until after P3D is up and the transponders are actually working.

Well, I sure hope that P3D stays generally available on mode A or J.  It's
what most of us has and I hope it stays available that way for a long time!
> Consider the combination of old Mode B (435 up, 144 down) with Mode L/S
> (1.2 gigs up, 2.4 gigs down).  Or even worse, suppose both operators
> transmit on 435 MHz, but one receives on 144 MHz and the other receives on
> 2.4 gigs.  

Tuning doppler on the higher frequencies must be a nightmare!  But it's a
good point, more than one uplink may be available at the same time.
> I suspect in such situations, we may develop a convention that one operator
> will adjust uplink while transmitting and downlink while receiving.

Well, I am a satellite newbie so perhaps I don't know much, but this seems
like the best idea that I have heard.  Perhaps a good way to say it would
then be "Tune the upper frequency when transmitting and the lower frequency
when receiving.  This could correct a lot of problems on both sides.



Jon Ogden


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

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