This idiot needs help!

I am scanning to attempt to locate a lost dog on our ranch with a
tracking collar on it. I do not know the frequency or the dog owner.
I do know the band is 217-218 Mhz. The collars are supposed to beep
about once a second.

I am scanning from 217.000-217.999 Mhz
I am using a 4 element Yagi antenna.
I have programmed an ICOM R8500.
I am sweeping at 10 Hz.
The scan takes about a half an hour.

QUESTION

Should the mode be set for FM, CW or CW Narrow

Thanks!

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