[Lowfer] WE2XGR/2 MFSK8, MFSK16

[Rick Kunath]

Jay Rusgrove wrote:

> I conducted local reception tests last night of the two modes - at a signal
> level about 15 dB above the receiver noise floor.   No antenna was connected
> and therefore the decoder had no noise or fading to contend with -probably
> close to ideal conditions for the decoder. BTW, the transmitter and receiver
> frequency accuracy here are about .01 Hz (both TX and RX are GPS
> disciplined).

<Snipped>

> Suppose another worthwhile battery of tests would be to run the various
> digital modes under both very weak and moderate signal levels to determine
> tolerable frequency error. Not all stations on the band will have
> 'laboratory grade' frequency stability, especially during an emergency
> communication period, so some digital modes may not be practical under those
> conditions. Perhaps John (if he's not burned out from the last tests!) and I
> can run tests over the near future to get a better handle on this issue.

Were the respective sound cards in the various machines that were 
generating and decoding the MFSK checked for sampling rate accuracy, 
sampling rate stability over time, and were any needed correction 
factors for differences between the expected and actual sound card 
sampling rates applied to the correction factor entries in the MFSK 
software?

Were the sound cards in use able to natively support the requested MFSK 
application's sample rate, or was re-sampling necessary? If so, what was 
the re-sampling accuracy set to in the Windows control panel, if these 
were Microsoft machines?

Rick Kunath