...under perpetual construction.
Measurements on a Hermes-Lite SDR v2 build 8.
Low-power driver output power vs. frequency for several TxPGA gain values (TxDAC gain, see the AD9866 datasheet for details).
The transformer provided by the H-Lv2b8 had too long leads and the wires used had a thick insulation with a thin conductor, which caused a power drop at the upper end of the HF.
After rewinding the transformer and keeping its connecting leads short the PA output was as expected.
The maximum output power is greater than 37 dBm (5 W) over the entire HF band:
and the two-tone third-order intermodulation products are at least 34 dB below each tone:
the ripples in the IMD level at low output power are due to the DC/DC converter feeding the PA, which changes mode of operation as the output current changes.
Here are the PA measurements results with the original transformer: