Just transmit on 20m band before little tuning (after tuning of the bias I’ve got around -54dbm of 2d harmonic). 60db att:
Also I’ve done some tests without photo:
40m band — 43.5dbm (22.39W) main tone, 3d harmonic 25.7dbm (371mW), 2d -10dbm.
80m band — 2d harmonic -5dbm, 3d 23dbm (199.5mW).
IMD3 14.1Mhz 22.39 Watt single carrier, 23dbc, 29dbc PEP, 60db att:
IMD3 14.1Mhz 17.38 Watt single carrier, 28dbc, 34dbc PEP, 60db att:
May be better, I think, but it’s already fine.