I have been using the Trimble R8 in RTK mode and have been having some issues with the radio link between the base receiver and the roving receiver. Firstly, I have managed to get the RTK to work with no issues at a coastal location(1) , and in the middle of campus. However, when it was set up exactly the same way (and with the same survey style) at a remote location on a different stretch of coast(2), far away from any towns or infrastructure, the base and rover receiver would not communicate with each other - i.e. a cross through the radio icon on the controller. I then tried to use the RTK again at the coastal location(1) and it still didn't work. I tried it again on campus (same set up and survey style etc.) and it worked. The distance between the base and roving receiver shouldn't be the problem; different distances were used during all attempts. The Trimble does not have an external radio, but I have been using a longer external antenna. Does anyone have any ideas as to what the issue may be?