The HELIX 12 CHIRP MEGA has many frequency selections under the CHIRP Configuration Menu (under the Setup tab) ...

It may be possible to select custom frequencies (or CHIRP sweep frequencies) that do not crosstalk with the fixed frequency choices in the G1 HELIX 10 ...

One would need to experiment with the CHIRP sweep frequency sliders in the HELIX 12 CHIRP mega and watch the results in each unit to determine what may cause crosstalk ...

Rickie