[amsat-bb] Re: Doppler Tuning Convention Question
vk3jed at gmail.com
Tue Jun 1 14:23:15 PDT 2010
At 11:31 PM 6/1/2010, Alan wrote:
>I've read the " Doppler tends to move more quickly near mid-pass than the
>computer and software routinely seem able to keep up". Mid pass is when the
>sat is moving most tangentially to you at which point Doppler shift is nil.
The rate of change of Doppler shift is at a maximum at this point,
which means you're moving the VFO knob fastest. It's like when you
hear a passing car, the change of pitch happens as the car is passing you.
Yes, the amount of Doppler shift might be zero then the satellite is
tangential, but the rate of change (in Hz/second) is maximum.
73 de VK3JED / VK3IRL
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