@M0YNG Between 5w to 500w if needeed.
The most time is 35-40w
@M0YNG For weak-signal VHF, 300 watts. Sometimes 10 milliwatts. On HF, I don't use FT8. I do use more effective digimodes on LF at full legal limit and on microwaves with either as much power as I can produce, or down to a milliwatt. "It depends"
@M0YNG FT8 start/stop envelope shaping and the Gaussian slides between tones have all but eliminated the old switching transient wideband splats, but I find it extraordinary that ops still don't have a clue about how to set levels. It ain't rocket science. Turn off any audio gain control, compression or processing. Cut any ALC connection to amplifiers. Switch it off. Disable it. Woteva. Monitor your TX power. Turn the FT8 power slider in WSJT-X down very low. Next, (1/3)
@M0YNG ...turn the power slider up until you reach the output level you want to achieve. Make sure that if you back off by 3dB that the PA output drops 2-3dB. If not, get a bigger PA or use less power. 1dB compression isn't going to ruin the inter-tone slides.
Make sure you have Fake-It or real split working enabled so you never transmit tones that are less than 1500 Hz, so even if your TX audio chain is truly terrible, you won't transmit in-band audio harmonics.
@M0YNG If your radio can't even support Fake-it, then either never operate with a tone less than 1500 Hz or get a radio that can do split or Fake-it. Make sure your radio has linear phase response to at least the maximum tone you intend transmitting, and that the amplitude response doesn't fall off a cliff anywhere, so you get imbalances between tones.
@M0YNG It's very basic stuff, but I still see folks who don't have a clue why they are sending multiple copies of their FT8 tones at 2/3/4 times the correct spacing because they haven't enabled split or fake and they are transmitting ludicrously high levels into a terrible audio transmit chain at less than half the audio bandwidth. I also see start-up splats where some n00b is using ALC to set the transmit level, when there's a flippin slider on the actual WSJT-X page to set the level. Sheesh.
@jmorris @M0YNG There's a competitive streak in some folks that means they just HAVE to be the loudest and the first to get a contact with $rare_entity. If they get a -18 report from the other station, then that power level is entirely justifiable, but if they are a lot louder than that, then it's a bit embarrassing, showing off for effect, "Look how loud I am". Yeah, slightly ewwww, like those folks who drive supercars in town. Hubris on steroids. Yuck.
@jmorris @M0YNG Trying to work the USA in full daylight, several hours after UK sunrise on 160 metres might need full-fat QRO, as might trying to work Alaska during a large aurora. I'm not one of the committed hair-shirt QRP brigade, despite being introduced to ham radio by the late George Dobbs, G3RJV, who was a visiting reverend at my secondary school. I just enjoy using efficient radios that are the right size for the particular application. Microwatts to kilowatt as appropriate