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Old 09-01-2016, 11:31 PM
mm mm is online now
Join Date: Dec 2002
Posts: 579

Your radios are working normally according to RF propagation theory

The rino6xx and 7xx radios are repeater capable of transmitting on gmrs repeater frequencies.

The rino 7xx are also capable of connecting and viewing live video from a Garmin virb camera, this is great for sneaking up or monitoring a virb remotely mounted near a trail or hunting stand.

I am the beta tester for garmin rino 6xx and 7xx radios and with all rino models you have to remember that notes will not be sent immediately but at some random time at up to 1 minute after transmit is initiated so if you are driving around inside a vehicle you don't know when the note is transmitted unless you are watching the display indicator.

As a result multipath fading and other analog users on the same channel can and do interfere with data packets resulting in a 50% success rate in a fast moving vehicle.

Also my test in a vehicle show an additional loss of 10 to 20 db in transmit and in receive due to surrounding metal from the vehicle causing multipath degredation.

Also when transmitting with notes only 1 transmission is sent so if you have even a small amount of multipath fading the receiving radio can loose enough of the data packet to where no text is decoded.

My mobile test in a truck only resulted in 3/4 of a mile range at ~15 to 35 mph vehicle speed and worse at higher speeds.

Holding the radio up near the center of a vehicle window for at least 1 minute to let the random timer count down typically results in a 10 to 15 % improvement in note range while in a moving vehicle again depending on speed and position between radios.

Outside in a standing position while fishing and hunting in Central Oregon, which is near where our design facility for some Garmin RF products is and where the beta testers live, my test resulted in 3-5 miles range in rolling hills with a fair amount of douglas fir trees in between.

In a more open hunting environment with moderate trees, pine and fir, the range was up to 7 miles.

But this is very important to achieve a higher success rate and reduce the effects of multipath it is best that the transmitting radio user stop and then stay stationary and initiate the sending of notes while holding the radio as high as possible and away from the users body and other nearby sources that can cause multipath issues.

While you cannot guarantee both users are stationary, at least having one user reducing multipath does increase the success rate of receiving the single random time transmitted data packet.

In these kind of tests I have had up to 95% success rates talking to and between rino 6xx and 7xx radios at several miles.

Our rino 6xx radios are being used by some Border patrol agents in Southern Arizona with these same techniques to reduce the effects of multipath fading with great success at similar ranges as mentioned above between the agents.

If the FCC had permitted a sending routine where the radio would transmit several data packets in a row instead of one single data packet burst then these techniques would not be required.

Last edited by mm; 09-01-2016 at 11:39 PM..
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