Thread: Discussion Hitec Aurora 9 Transmitter
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Old Nov 13, 2012, 07:52 PM
A.T. is offline
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Transmitter and Receiver Antenna Orientation for best 2.4Ghz Reception

Originally Posted by S_YORAM1@BEZEQIN View Post
Both had an Optima 9 receiver - and they were 2 different receivers, i did not install the crashed one in a new model.
The antennas were pointing span wise and lengthwise, with none pointing vertically.
Both crashes happened when the models were flying downwind, almost in front of me, at medium altitude, and straight and level.
Both showed an uncontrollable right hand roll, followed by a spin.
"The antennas were pointing span wise and lengthwise"
Horizontal 90 degree is not recommended as this presents a flat plane which is more easily blocked
by engine etc on landing approach, (or "low and level coming close in") especially if Tx antenna is also in similar plane.
Given the cost users are prepared to pay RC "sport" equipment, nothing will ever provide a 100%
guarantee that Sh** will not occur sooner or later for whatever reason - even military drones go astray.

. Optima Transceiver & Minima Receiver - Installation RX & BODA Antenna FAQ {Regularly Updated with Q&A}
Shows previous recommendations to situate dual antenna so one leg is vertical with the other
horizontal. This to cover all "planes", especially for the landing approach of large models when Tx
antenna may also be held in a flat plane toward model.

Transmitter antenna orientation is highlighted in the Australian MAAA Policy on 2.4GHz equipment (.pdf)
" It is very important to consider how this technique affects the landing
as it may result in the model approaching from a position in
line with an end of the transmitter antenna, giving a greatly reduced range
• landing is a critical situation for any loss of control, as the model is low giving
no margin for recovery. A resulting crash may be near where other pilots are

. The 2-Point-4 Chronicles .pdf "You and the Tx Antenna" = pictorial pages 15 & 16 (copy attached)
. The 2-Point-4 Chronicles update
"keep the antenna perpendicular to the plane as much as possible for best results"

Replacement 2.4GHz Antenna:
. Hitec 2.4Ghz BODA Antenna search " 2.4RXANTENNA "
otherwise international 700892 but first digit may vary
. Hitec 2.4Ghz TX(Spectra) Antenna (without base) search " 2.4TXANTENNA "
. Receiver - Antenna - Original lengths & DIY Replacements for PPM & 2.4Ghz Hitec, Futaba, GWS, JR & others.
Includes pictures of 2.4Ghz antenna U_FL Connector head & base which have a maximum removal/refit of 5 times.

Alan Tong
Alan's Hobby, Model & RC FAQ Web Links

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Last edited by A.T.; Dec 01, 2012 at 01:50 PM. Reason: attach .jpg ex Spectra manuals
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