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Re: FO-29 Freq



Robert Jewell wrote:
 
> Translation Equation:
> 
> downlink = 581.800- uplink freq (plus or minus doppler).
> 
> NON inverting.

Robert, why do you say NON inverting?  It most certainly *IS* an
inverting transponder.  That's how I have it programmed into my
FT-847, with LSB on the uplink and USB on the downlink, inverted
tracking, and once the Doppler is factored in, I can tune up and
down the passband with the main tuning knob and the uplink and
downlink stay correctly adjusted with respect to one another.

Even your equation shows it.  As the uplink increases, the
downlink decreases, and vice versa.  For a NON-inverting
transponder, the equation would be in the form of
  downlink = offset + uplink
so that as the uplink increases, the downlink also increases.

The basic frequencies for either FO-20 or FO-29 in JA mode would
thus be, before Doppler correction:

Uplink     145.90 (bottom), 145.95 (mid), 146.00 (top)
Downlink   435.90,          435.85,       435.80

There was an email message announcing an updated "Fuji Transponder
Map" on this list within the week, but I don't have the URL handy
now.  This "map" showed more precise sets of numbers for the
uplinks and downlinks on the two Fuji birds that are slightly
different than the short table above, due to a drift in the
working frequencies of the transponders on the two spacecraft over
the years.  So there are actually two equations, one for FO-20,
and one for FO-29, that are slightly different than the one you
listed above.

John (KBØZEV)
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