Do you equip your "backup spotter" with a walkie-talkie?

We have radios in case we don't have cel coverage, but cel phones work MUCH better for one simple reason: With radios, only 1 person can talk at a time. If the spotter is holding down the 'talk' button, the driver can't be heard in case they have a question.

Also, before I back in, I figure out where I want the trailer and any obstacles to look for. Then I relay this to my wife so we're both on the same page. Works great.