I think that’s incorrect. I think the cellphone is messing up the recorder. We have several editors whose cellphones drive us crazy. Every time they get a call, all the computer speakers in the office go nuts.
BRBRBRBRBRBR__tick_tick_tick_tick_ BRBRBRBRBRBRBRB.
You need to separate the two or shield the recorder. As an experiment, wrap the recorder in aluminum foil and make a short recording.
If the interference is anything like what we get, you can’t take it out in post production.
Separation can be as simple as mount a cellphone holster to your leg just below the knee and continue to hand-hold the recorder. That may be enough. If you’re hand-holding them both that’s asking for trouble.
Koz