The original was not that bad ;)

what about
  6. Ensure that the radio is tuned to channel with no activity.


On Friday, October 18, 2013 4:00 AM, IZ3GME Marco <iz3gme.marco@gmail.com> wrote:
On 18/10/2013 02:06, Dan Smith wrote:
> Hi Marco!
>
>> +            6. Make sure there is no receiving signal on current channel.
>
> This might be a little confusing for native speakers.
>
> How about "Tune to a quiet channel"? Anyone else have a better short
> phrase for this?
>
> Thanks!

And "Tune to a quiet channel where no signal opens the squelch"?

Any way, as usual, feel free to translate my itanglish before to commit :)

73 de IZ3GME Marco