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Re: PSK-31 MFSK Hell via AO-10



> concerning the doppler shift of AO-10:
>
> For 146 MHz  91% of the time < 0.5 Hz/sec
>              94% "  "   "    < 1.0 Hz/sec
>              98% "  "   "    < 2.0 Hz/sec
>              max. shift        4.0 Hz/sec (around perigee)
>
> For 435 MHz  85% "  "   "    < 0.5 Hz/sec
>              90% "  "   "    < 1.0 Hz/sec
>              92% "  "   "    < 2.0 Hz/sec.
>              max. shift       12.0 Hz/sec (around perigee)
>
>
> But the low duty cycle of Hellschreiber if a serious argument.
> The batteries of the old bird AO-10 are not in the best shape...
>
> 73, Udo, DL7OL ***
>

Hmmm.  So maybe +/-20Hz/sec AFC would do it.  As someone mentioned, one
could enter your QTH coordinates, the tx frequency, and the Satellite's
KEP's and use some calculated feedforward AFC but is probably not worth it
with these small doppler rates.

I'm not sure I understand the issue of duty cycle and weak batteries.  I
would think average power is average power.  1 watt rms Hellscreiber = 1
watt rms CW = 1 Watt rms PSK31 = 1 watt key down carrier.

PSK31 takes about 3dB less average power than FeldHell so just use half the
juice you would use for FeldHell.

I'll post something here when I get a modified version of WinPSK for full
duplex and fast AFC.
Just when i thought i was through with PSK31 forever...;>(

Guess I'll have to postpone work on that 10 Gbit/sec VMSK tranceiver that
uses audio bandwidths and super low S/N ratios and Radio Shack parts. (just
kidding Phil!)

Moe,ae4jy




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