Irrespective of what you choose to do with your radio.....Could I please just add my ten penny-worth on a slightly different tack?
If your aircraft is fitted with a transponder PLEASE use it when operating in the open FIR. Also, if it has an "Altimeter encoding" setting then it's important to use that too.
Many police aircraft are now fitted with TCAS (which detects aircraft transponder outputs and presents them as icons on a small screen as a range and bearing, for those not aware). We need TCAS as an extra pair of eyes, very important due to our vulnerability when operating at low speed or in the hover. (A light aircraft up the tail-rotor takes the edge right off our day, and yours too)!
If TCAS gets a conflicting transponder target in range & bearing without attached height information, a false "Traffic, Traffic" alert (20 seconds to impact!) will be generated even though we may be well separated in altitude. This often causes an overload of adrenalin as we have to decide which way to manoeuvre to avoid this false alarm! Very worrying when the aircraft generating the warning can't be seen due to the height separation.
This problem also applies to other aircraft fitted with TCAS and it affects ATC too.
TA! SC.