IN3LBQ on the Hühnerspiel (Amthorspitze) - photo by IN3OTD

Hermes-Lite SDR v2 build 8

Measurements on a Hermes-Lite SDR v2 build 8.

TX measurements

Low-power driver output

Low-power driver output power vs. frequency for several TxPGA gain values (TxDAC gain, see the AD9866 datasheet for details).

H-Lv2b8 low-power driver output

PA output

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:

H-Lv2b8 PA output

and the two-tone third-order intermodulation products are at least 34 dB below each tone:

H-Lv2b8 PA IMD

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.

Initial data

Here are the PA measurements results with the original transformer:

H-Lv2b8 PA output H-Lv2b8 PA IMD