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Antenna Position as Far as the Planes of Said Antennas

Old 08-01-2012, 10:30 AM
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dwaynenancy
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Default Antenna Position as Far as the Planes of Said Antennas

I am mounting the main receiver antennas in a horizontal position and I am mounting the satellite receiver in a similar horizontal position. The planes of the antennas are separated by approximately 1 inch. There is no vertical component of the antenna. Does anyone have a comment on this mounting scheme? In my mind's view I see all the antennas are in the horizontal plane. Horizon has said the plane of the antenna serves no purpose.
Old 08-01-2012, 11:11 AM
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Default RE: Antenna Position as Far as the Planes of Said Antennas


ORIGINAL: dwaynenancy

I am mounting the main receiver antennas in a horizontal position and I am mounting the satellite receiver in a similar horizontal position. The planes of the antennas are separated by approximately 1 inch. There is no vertical component of the antenna. Does anyone have a comment on this mounting scheme? In my mind's view I see all the antennas are in the horizontal plane. Horizon has said the plane of the antenna serves no purpose.
I am sure that Andy will confirm, but it has always been stated that the Satellite Rx's should be mounted 90 deg from the Main Rx. If the Main Rx is mounted on the floor of the Fuselage, for example, the first Satellite would be mounted on one side of the Fuselage, with the antennas pointing top to bottom.

Where does Horizon say the orientation does not matter?
Old 08-01-2012, 01:21 PM
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Default RE: Antenna Position as Far as the Planes of Said Antennas

Get the orientation at right angles. Watch the video John Redman did. It's super.

Andy
Old 08-01-2012, 04:58 PM
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Default RE: Antenna Position as Far as the Planes of Said Antennas

90 degrees apart is the rule and if you have three antennas then you have your vertical component, otherwise with only 2 antennas they will always be in one (parallel) plane. If you have more than 3 antennas then you position it at 45 degrees.

Video says 3 inches apart minimum.

Here's Horrizon's video

[link=http://www.youtube.com/watch?v=tXFfJUGUH_U]http://www.youtube.com/watch?v=tXFfJUGUH_U[/link]
Old 08-02-2012, 08:07 AM
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dwaynenancy
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Default RE: Antenna Position as Far as the Planes of Said Antennas

Rich, I was told that a technician at Horizon told the other flyer that parallel antennas was a satisfactory orientation. That's all I know.
Old 08-02-2012, 08:27 AM
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Default RE: Antenna Position as Far as the Planes of Said Antennas


ORIGINAL: dwaynenancy

Rich, I was told that a technician at Horizon told the other flyer that parallel antennas was a satisfactory orientation. That's all I know.
Ok! I have always read that you get the best antenna Diversity when the antennas are not in the same orientation. It would seem that there would be less chance of a Frame Loss.
Old 08-02-2012, 09:56 AM
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Default RE: Antenna Position as Far as the Planes of Said Antennas


ORIGINAL: dwaynenancy

Rich, I was told that a technician at Horizon told the other flyer that parallel antennas was a satisfactory orientation. That's all I know.
Dwayne, you have to realize you're getting the message third hand: "he said, that she said, that someone else said" etc. Perhaps the technician said that it wouldn't hurt anything to mount them that way, and it won't. You just won't get any benefit from the satellite rx that way.

I've been an amateur radio operator (ham radio) since I was in high school and I have a degree in electrical engineering. And if it's one thing that hams understand, it's antennas. I guess most people have no concept of the radiation patterns of antennas so let me give you the quick and dirty.

The antennas receive mostly from a perpendicular direction. They do not receive signals coming at them from the direction that the ends of the antenna are pointing. They receive "broadside". The purpose of mounting them at right angles to one another is to try to eliminate any deadspot as the plane turns or rolls. If, for example, you mount the rx's such that antennas are all in a straight line, front to back along the fuselage, then those antenna ends are pointing right at you when the plane is coming directly toward you. Hence they will receive only a very weak signal at that time. But if you mount the rx's in a perpendicular manner, then one of the rx's will be broadside to you as it comes toward you and will receive a good signal.
Old 08-02-2012, 10:10 AM
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Default RE: Antenna Position as Far as the Planes of Said Antennas

doug -well stated.

And the new DX18 has orthogonal antennas in the transmitter.. I think that's another good idea, too. Helps with polarization issues in the signal.

Old 08-02-2012, 11:14 AM
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Default RE: Antenna Position as Far as the Planes of Said Antennas

90 degrees apart in different planes is the preferred for receiver antennas. It's also likely that the transmitter antenna should be in a horizontal position across the top of the transmitter.

Admittedly, there can be conflicts. A HiTec receiver or receivers for "carbon fiber" have antennas long enough to make vertical orientation a problem.
A Spectrum AR600 has a long and short antenna. In this case, the horizontal antenna is usually the longer one for convenience in mounting.

Also consider that in "normal" flight the receiver's horizontal antenna is more or less horizontal.

There is a situation caused by two short antenna receivers and remotes that might be considered.
Should both antennas on the same unit be oriented the same way?
Old 08-02-2012, 01:37 PM
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Default RE: Antenna Position as Far as the Planes of Said Antennas


ORIGINAL: chuckk2

There is a situation caused by two short antenna receivers and remotes that might be considered.
Should both antennas on the same unit be oriented the same way?
Well the short answer to that would be "yes". Any other configuration would result in a distorted antenna pattern. Now that's not necessarily bad, it's just unpredictable. Keep 'em straight out and if you have satellite receivers they should be oriented 90 degrees apart.
Old 08-03-2012, 03:02 AM
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Default RE: Antenna Position as Far as the Planes of Said Antennas

Good and easy to understand explanation of antenna's Doug.

I have one in the horizontal plane, one in the vertical plane.  The Vertical satellite receiver has two stubs so one goes across the fusealage, one goes up and down, and the main Rx has its antenna going fore to aft as does the antenna for the TM1K.

Broadside is the key, I have all the possible orientations covered.

KKKKFL
Old 08-09-2012, 11:34 PM
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Default RE: Antenna Position as Far as the Planes of Said Antennas

Receiver two short antennas
Remote two short antennas

Standard advice is to mount them so that the antennas on each are parallel, and
at 90 degrees between units. It's possible to route the antennas differently, so that at least one is at at least 45 angle to the others.
I usually do this when the natural position of one units antenna is parallel to such things as metal control rods, or wiring.
I can't say if the results are an improvement or not, since I haven't had any recent (Knock on Wood) loss of control problems.
The problems I had some time ago were on models with the antennas oriented per the standard recommendations,
although that was not believed to be the cause. Brownout was the most likely culprit.
Old 08-10-2012, 05:09 AM
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Default RE: Antenna Position as Far as the Planes of Said Antennas


ORIGINAL: chuckk2

Receiver two short antennas
Remote two short antennas

Standard advice is to mount them so that the antennas on each are parallel, and
at 90 degrees between units. It's possible to route the antennas differently, so that at least one is at at least 45 angle to the others.
I usually do this when the natural position of one units antenna is parallel to such things as metal control rods, or wiring.
I can't say if the results are an improvement or not, since I haven't had any recent (Knock on Wood) loss of control problems.
The problems I had some time ago were on models with the antennas oriented per the standard recommendations,
although that was not believed to be the cause. Brownout was the most likely culprit.
When positioning antennas, the goal is to create a situation where the Tx signal is never blocked by anything in the aircraft. You can do Range Checks while someone rotates your aircraft. Ideally, you would use a Flight Logger or Flight Log Telemetry, if your Tx permits that. Look at how many Fades a particular antenna is getting and if the numbers are too high, reorient the antennas until the situation improves.
Old 08-14-2012, 12:03 AM
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Default RE: Antenna Position as Far as the Planes of Said Antennas

On my A/C with telemetry, the fades are usually quite low, less than 10 per antenna on the usual flight. In rehashing the two A/C that had problems last fall.
1. The 60A speed contol"s 2A 5v BEC's were used.
2. It was possible to "stall" some of the servos at the end of travel. One plane has flaps, and we suspect that the servos might have been stalled in the flap up position.
3. External 6A BEC's were installed, and any servos that were capable of driving control surfaces to mechanical stops or when full stick deflection might drive a servo to an internal stop were re-adjusted. (linkage, centering, and even transmitter travel/span.)

Unrelated testing of typical four cell AA NiCad and NMIH packs showed that an AR600's LED might blink when the momentary battery current draw was high, perhaps close to 2A, due to a drop in battery output voltage. My meters are not fast enough to accurately show the momentary drop in voltage, or the current causing it.
That said, the current was in excess of 1.5A, and the voltage drop must have been to well below 4V. The fooler was that the same battery packs voltage at full charge did not usually drop far enough to cause the AR600's LEDto blink.
Old 08-17-2012, 09:08 PM
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Default RE: Antenna Position as Far as the Planes of Said Antennas

Can I mount a satellite receiver next to the gear's large air tank? Or would it suffer from interference?

Thanks,

Bob I.
Old 08-18-2012, 04:04 AM
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Default RE: Antenna Position as Far as the Planes of Said Antennas


ORIGINAL: NUMB LOCK

Can I mount a satellite receiver next to the gear's large air tank? Or would it suffer from interference?

Thanks,

Bob I.
Range test and see. If you have Spektrum Rx's, use a Flight Logger to check for Fades on each antenna.

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