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FT-847 replacement: suggested feature



>  RE: [amsat-bb] FT-847 discontinued?

Hello all,

With all the PC-based rig automation / rotator automation going on (yes, I 
have SatPC32 and HRD), this is probably water under the bridge.  But there 
was this thing about the 847 that always bugged me in satellite operation. 
How difficult would it have been to make the Sat mode cross-band tracking 
proportional to frequency (like the doppler is)?  As a good approximation, 
have the radio work like this:  For every 1 Hz I tune up on 2m, tune 3 Hz 
down on 70 cm  (145 : 435 is 1:3), or for every 1 Hz I tune up on 10m, tune 
5 Hz down on 2m (29 : 145 is 1:5).  The rig is capable of 0.1 Hz synthesis, 
so this could be really smooth.  These integer proportions are close enough 
to the actual doppler ratios as to make tracking by hand, without a 
computer, almost reasonably possible.  Certainly easier on other stations on 
the bird than the current 1:1 tracking.

70 cm :  2 m  ~  3 : 1
70 cm :  6 m  ~  8 : 1  or maybe  9 : 1
70 cm : 10 m  ~  15 : 1
2 m  :  6 m  ~  3 : 1
2 m  :  10 m  ~  5 : 1
6 m  :  10 m  ~  2 : 1
[similarly for 902 MHz, 1.2GHz, 2.4 GHz, and even 15m (remember RS-12!)]

Save the 1:1 reverse tracking for in-band split (non-full-duplex) operation, 
like for ARISS contacts.  Tune the primary VFO up 1 Hz and the sub VFO goes 
down 1 Hz.  An ARISS contact operator can track doppler just by watching the 
discriminator center meter....

It would be too cool if Yaesu could release a firmware update (or someone 
could hack the firmware) so the 847 could do these things.  But I think the 
rig uses ROM, not EEPROM or FLASH.  Bummer.

Could one of you PIC or HC908 experts out there come up with a little gizmo 
to plug into the serial port to make "proportional" doppler (tuning as 
described above) happen?  If it fit in a 9-pin shell and got power off the 
handshaking pins, then it could be plugged into the port and left in place 
for Field Day and the like.

I know, I know:  shoulda had that idea ten years ago...

Happy holidays to all!
73,
W8ABZ, Dale
Cleveland Heights, OH  USA  [EN91]
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