Standard G/C gurdy-gurdy tunings

From the archives of the hurdy-gurdy mailing list here, Simon Wascher posted a useful summary of the standard G/C hurdy-gurdy tunings:
Drones:
- G at 98 Hz (corresponds to second lowest string of cello)
- c at 131 Hz (corresponds to lowest string of viola)
- g at 196 Hz (corresponds to lowest string of violin)
Trompette
- c’/d’ at 262/294 Hz (d’ is the second lowest string of the violin)
Chanterelles
- g’ + g’ at 392Hz