FST4W now successful on 70cm in Northern California, participants wanted!
n6gn
After considerable fuss, WB7ABP's station is now transmitting FST4W using a QRPlabs QDX TRansverter and an n6gn TRansverter with a 2nd Kiwi for receive on 70cm. An original Kiwi is still reporting HF HF, with spotting and reporting handled by wsprdaemon.
At the moment only K6PZB has also moved from WSPR to FST4W -120 and spots are being posted. Because WD at WB7ABP is used, data above and beyond that from WSJT-X is being posted to wsprdaemon.org and allows examining not only the usual SNR etc information but also spectral spreading. To my knowledge this is the first time anyone has tried the mode out on 70cm.
Early results are looking quite encouraging. Overnight reports from Lynn's WD show an average spectral spread of under 50 mHz (milli-Hz) for the ~5 mile non-LOS path and frequency errors under 1 Hz. Considering that this is about 20 times the frequency of previous HF FST4W experiments, this seems quite good. It means for completely different systems separated by imperfect paths at UHF small parts-per-billion discrepancy is being maintained. Congratulations to both.
Previous HF measurements of non-ionospherically propagated signals at HF
have indicated that very precise measurements like t his are likely able
to reveal subtle details about our radio communications. For example,
it looks like we are able to discern and measure the effect of wind
gusts and barometric pressure changes modulating the dielectric constant
of our atmosphere. FST4W can measure changes in the the dielectric constant of air and
see radio waves literally blowing in the wind.! This addsa whole new
dimension to our previous measurements.
It may also be that at 70cm we can see our antennas swaying back on
forth (if they do) and other phenomena not previously evident. Where
this all might lead is unknown to me but it seems interesting and worthy
of further investigation. We don't know what we might discover.
Towards this end, I'd encourage all capable of 70cm WSPR to move to FST4W to participate and allow further study. It would be good to first verify capability with another 'local', if possible.
While wsprnet.org can continue to be used, other tools such as
can give additional insight.
Glenn n6gn