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Re: Doppler correction?



At 10:14 AM 11/14/2003 +0000, Robert Turlington wrote:

>Thanks Anthony
>it woprks fine ,I wonder what the upper limit for updating the frequency 
>would be??

Hi Robert,

That that depends somewhat on what kind of PC you are
using and how fast it can do floating point math.

The DOS timer tick is ~55 milliseconds and I COULD
make it run every tick instead of every 8 ticks.
I am a little concerned about how some of the radios
would react to this though.

It is also possible to reduce the DOS tick time
to something like 1.7 milliseconds but this isn't
the real limit.

The realistic limit is how fast you can talk to the
radio and how fast it will accept messages and
respond without choking. For an FT-847 running
at 9.6K bps, the serial port speed limits you to
about 20 updates per second. You can bump the
serial port rate up to 56K but it isn't clear the
FT-847 could really take this.

So, I would guess that it could probably run 2x
faster for most radios and perhaps 4x faster for
some radios.

73,
Tony AA2TX




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