Transmission distance depends on many factors including terrain, type and thickness of vegetation, antennae type and elevation, camera type, reflective or blocking structures and objects, cable and other impedance sources and RF interference.  The maximum transmission distance of an X80 is 13 miles and for the X7D it’s 2 miles.  Orion cameras can transmit 26 miles or more.  Check out the BuckEye Cam website for more info.

X80 PC Standard-Standard Site 2

Comparison of the X80 and X7D transmission distances using standard antennae.

We were unable to find any “real world” information on the Internet so we have taken our X7D, X80 and Orion cameras out for field surveys.  Basically we walk away from the base station until we lose communication with the base.  Using a topo app and the GPS in a smart phone, we store a waypoint (a red dot for the X7D and a red square for the X80) indicating where  we lost the signal.  Then we head clockwise almost tangentially to the base but a little towards it until we get a good signal again.  Here, we store another waypoint (a green dot or square).  Then we head tangentially but angling a bit away from the base until we lose the signal and mark another red dot or square.  We repeat this sequence over and over as we go clockwise around the base station.  In the end, we have a 360 degree map of the transmission distance for that situation.

Since so many factors affect transmission distance and every installation is unique, these surveys should not be viewed as a comprehensive assessment of the performance capabilities of the systems.  They involve many of the “worst case” of the variables mentioned above; limiting terrain, thick vegetation, pine trees, and the most basic antennae mounted at ground level.  In time, we hope to supplement this information with representations of the upper end of the performance scale.

Here is a survey in the same location with an X7D and an X80 with a PC base, all with standard antennae.  Where terrain is the limiting factor, like to the east, the X80 still reaches out a bit farther than the X7D.  But where there is no terrain blocking the base, like to the south, the X80 greatly increases the transmission distance. We were getting a strong pretty strong signal to the south but it dropped off sharply as we went over the rise.  So the X80 would have transmitted a good bit farther to the south, but terrain blocked it.

So it seems that the X80 can significantly increase transmission distance over the X7D, but it cannot perform miracles by transmitting through the earth.  We will learn more as we do more surveys with the X80 where we have  done surveys with the X7D.

X7D PC Standard-Standard Site 3 10-1

X7D transmission distance survey using standard ground-based antennae.

The next survey involved mostly flat terrain, but thick and various vegetation mixed with open fields.  As you can see, we got from 0.2 to 0.4 miles (1,000 to 2,000 feet) transmission distance with an X7D and PC base with standard antennae.  Unfortunately, we could not access the property to the north and could not test the limits in that direction.  Topographical features and vegetation have a significant effect.  These were taken with full fall foliage so it will be interesting to see if the results change without leaves.  Notice how the transmission distance increases in the image to the left in the NE direction and in the next image to the South.  In both cases, open fields between the base and the camera allow the signal to reach out.

The next images are from the same site, but with a ground-based Orion Cell Base antenna and camera with standard ground-based mini-yagi antennae on the left and an ground-based X7D and PC base on the right.  On the Orion image, color corresponds to signal strength with black squares showing no signal.  The Orion set-up reaches out farther than the X7D.

Orion camera and Cell base.

X7D and a PC base

Here is a good site with instructions on using your cell phone to measure cellular signal strength.  This can be handy when trying to find the best place to locate a CellBase antenna.  Remember that the measured signal strength will be relative; it will not necessarily be the same as the signal received by a CellBase.  But the best place for a cell phone signal will be the best place for a cell base antenna.

http://www.ubersignal.com/field-test-mode