2.4 g dual antennas

Old 11-05-2013, 10:42 AM
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Default 2.4 g dual antennas

What do you all think about dual antennas on 2.4g receivers ? Pros& Cons.
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Old 11-05-2013, 02:31 PM
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The is no real con other than having to route the external one's antenna wire. The pros would be questionable though considering even micro receivers with internal antennas only often list a reception distance larger than any track you'll ever see anyway. In other words, I wouldn't go out of my way to buy a dual antenna receiver.
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Old 11-05-2013, 02:58 PM
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I'd like to see some manufacturer measurements on diversity antenna use indoors. Range isn't the issue, but resistance to interference or multipath would be a useful benefit.
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Old 11-05-2013, 05:54 PM
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I was under the impression, the dual antenna was for telemetry for aircraft. They have many more servos, motors to keep track of, and 2 antenna handle the signal better.
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Old 11-05-2013, 06:37 PM
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They are for aircraft...period. Has nothing to do with telemetry, has to do with maintaining 100% signal no matter what attitude the plane/heli is in. That's why the two antenna's that come out of the Rx have to point in different directions.
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Old 11-05-2013, 07:43 PM
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Originally Posted by Johnnysplits
They are for aircraft...period.
Not true.

From Futaba's description of the R614FS (which is a surface receiver for the 4PKS/4PKSR). Only one antenna is external.

The R614FS (FUTL7635) is compact, with a high-voltage design, fail-safe, DAD (Dual Antenna Diversity) and the push-button ease of the Easy-Link™.

http://www.futabarc.com/systems/futk...ksr/index.html
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Old 11-06-2013, 12:19 PM
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Asked Futaba about dual ant. They call it a dual diversity ant. Which ever ant. receivesthe best signal that's the one that's used. Simple explanation.
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Old 11-06-2013, 12:45 PM
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Originally Posted by Ken Webb
Asked Futaba about dual ant. They call it a dual diversity ant. Which ever ant. receivesthe best signal that's the one that's used. Simple explanation.
The way diversity antennas work is that the PHY looks at the RF energy present at each antenna prior to the start of the "packet" of data (called the preamble). Most diverstiy algorithms just select the antenna with the strongest signal as the "best", which it might not be. For digital data, they don't switch in the middle of the packet, as that results in lost data. The strongest signal may be due to multipath (two reflected signals adding together), or from a stronger interference generator (like a leaky microwave oven, or a WiFi device transmitting in the vicinity).
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Old 11-06-2013, 05:14 PM
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Overkill for surface use
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Old 12-07-2013, 10:31 AM
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Default dual antennas

Is it possible then to for ex when driving 1/12 electric to remove the external antenna and only use the internal ?
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