Calibrated signal generator at harmonics

Even the XG2 manual mentions that the circuit produces useful harmonics at predefined levels. Using the 14.000 MHz XTAL and the IC706MKiiG as a test instrument I recorded the following:

1. 14 MHz: S9
2. 28 MHz: S8
3. 42 MHz: S6
4. 56 MHz: S3
5. 70 MHz: no signal, barely audible

I cross-checked 2nd and 3rd harmonic readings with FT-817 too.