Now that JT-65 and JT-9 are gaining in popularity I thought I would pass along a tip to avoid a problem I ran into tonight.
While operating WSJT-X I tried replying to a station running JT-9 @ 2900 Hz. My power out was 1/4 of what it should have been, resulting in poor signal received by DX station and retries.
I noticed I had DIGI-U TX bandpass set to 100 - 2900. I opened it up to 100 - 3100 and made two more contacts tonight @ 2900 Hz with no drop in power from where I have it set. The two stations I contacted at 2900 HZ were -26 and -28 signal while my report was at least 10 higher. They are probably using radios limiting their TX passband (modern Icom is 100 -2900 Hz)
So the tip is to check your TX bandwidth if planning on JT-9 mode.