Would appreciate insight on efficiency of PSK31 on various HF band.
Would 300 to 1000 km generally achievable if suitable band are chosen, according to day night and sun spot cycle using low power QRP and simple 3 meters vertical antenna?
Please fill in the table like below. I only have VHF FM license. No experience on HF nor digit modes. Assume 5 watts, vertical antenna of about 3 meters, retransmission allowed. May be aiming for says 70% chance of the message transmitted success rate.
3.5MHz,
Best sun spot cycle, 300km day, 400km night
Worst sun spot cycle, 200km day, 300km night
Present sun spot cycle, 250km day, 350km night
..... other frequencies.....
73
=========== answer my own question
http://www.voacap.com/hf/ I found this site which answer my question. One can enter two QTH and it predicts propagation, received signal in dBW, SNR for time and months