A couple of days ago I had a reply to a CQ call from a German station, the signal was very strong but after many connect attempts all I saw was a callsign. The signal sounded distorted, probably due to over driving the radio. I couldn’t send him an email as he didn’t show one on qrz.com
I find that running 1/4 to 1/2 max power and little to no ALC seems to give the most reliable comms.
Working 10,000 to 11,000 mile paths to fairly ordinary antenna equipped stations (G to VK and ZL) seems reasonably easy with my modest doublet on 20m. No need to run QRO or “flat out”.
Just my 2c worth.
73 Dave
Well, I have just followed the guidance and have my FT450D running at 25 watts with ALC at approx 1/ , according to band.
See VAR to be on 15m today...QSYing now but busy away most of morning
73
Victor
Quite agree Dave! In fact, I understand that the digi stations are providing a 'nice little earner' for our dealers repairing linears driven to max on FT8!
Victor G3JNB
When in doubt, go wide open. QRO ;) It may not improve the situation but will end the suspense.
Except the illustration shows less than 25 Watts from what looks like an IC-7300.
The Vara specification includes this:
”The OFDM signal has a noise like amplitude with a very large dynamic range, therefore it requires RF power amplifiers with a high peak to average power ratio.”
OFDM modulation requires a highly linear transmitter, as such running less than 50 Watts from a 100W PA is essential for minimum distortion and maximum throughput.
73 Dave
I think in the end it all boils down to ALC level regardless to your power level.
I work 100W with 1/3 ALC as the VARA MODEM author recommend and it works perfectly fine for me.
See attached screenshot from the VARA MODEM sound settings and the 1/3 recommendation made by Jose himself.
73s
Irad