Radio Issue Ranger 3 with Trimble

Hi

I am using Spectra Ranger 3 but with Trimble SPS 620 robotic total station.

Recently I have problem with radio : when?ÿ I am over 80 meters from instrument

radio signal begin to stop and I see on the display that instrument losts connection

Earlier distance of about 200 meters was not a problem like now.

I think that problem is in the controller not with Trimble robotic.

?ÿ