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Truth or Myth about 2.4 antenna

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Old 03-02-2008, 09:16 PM
  #1
WRM
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Default Truth or Myth about 2.4 antenna

The so called experts say that the antenna on a 2.4 radio transmitter has to be at a right angle or you will point the antenna at the plane and you will get a very weak signal, or the cone of silence which could cause the plane to crash .

Model Airplane News Sept. 2007 states that the knee in the antenna is so you can bend it to fit into the transmitter case.

Which one is right the experts or Model Airplane News?
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Old 03-02-2008, 09:57 PM
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Default RE: Truth or Myth about 2.4 antenna

I was told that bending the antenna multiplies your coverage over straight configuration. It makes sense.

Just like placing your RX pickups in your fuse at contrary angles to increase your reception.

Jim
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Old 03-03-2008, 05:23 PM
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Default RE: Truth or Myth about 2.4 antenna

Well, Mariner_Jim has been told an absolute pile of crap. The folded dipole antenna is entirely in the end piece and does not bend. The radiation pattern is perpendicular to the antenna (end piece) and you should not point the antenna (end piece) at the plane. That being said, 90% of the pilots at my club fold the antenna up 45 degrees, hang the transmitter from a neck strap and point the antenna at the plane.
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Old 03-03-2008, 06:39 PM
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Default RE: Truth or Myth about 2.4 antenna

I'm deeply hurt by that.

Oh, well, frig it. Maybe YOU were told a pile of crap. I like the way I think about it, and I never crash.

My planes never have a problem, so I'm good either way!

Okay, so maybe I'm too old and mean and grumpy to be deeply hurt, but except for those little things I probably shoulda been!

I feel the empathy oozing my way from you guys....right?

Hehe...
Jim
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Old 03-03-2008, 06:44 PM
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Default RE: Truth or Myth about 2.4 antenna

You of's are too funny, I fly only turbine jets and a JR rep told me you bend it up. But I would not need to tell you guys, nor did I need to be told because I know how radio frequency's look when they are transmitted.

Pointing your antenna at your airplane on any frequency is a bad idea, however, experience suggests that in our application with the 2.4 it does not matter.

That being said, fly your airplane with the data logger a couple of times each way and you will have your definitive answer DUH!
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Old 03-03-2008, 06:48 PM
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Default RE: Truth or Myth about 2.4 antenna

Since this is the direct support forum, how bout we wait and see what Danny has to say ?
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Old 03-03-2008, 06:50 PM
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Default RE: Truth or Myth about 2.4 antenna

According to my records he already answered it and it got deleted when they refreshed the database this afternoon.
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Old 03-03-2008, 06:51 PM
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Default RE: Truth or Myth about 2.4 antenna

Really..so what was the "official" response ?
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Old 03-03-2008, 08:29 PM
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Default RE: Truth or Myth about 2.4 antenna

Why, we'll never know because the tip of his antenna was pointed toward us when he answered. The REAL word has been lost....in the CONE OF SILENCE..............

I get all goosebumpy whenever I have to say those words!

Jim

Oh, and seanreit, I know how they look too...I'm an engineer. Look out through that pane of glass in your window...that's how they look...they're invisible.
Now, if you wish to know in what manner they typically eminate and what factors are involved in their proliferation, dissemination, coverage, refraction, deflection, and remission, then I could DRAW some diagrams of that for you......
Personally I just like it when they bounce around all over and make my plane fly around in the sky really cool-like.

Signed, just an Old Fart............Turbines bore me. Stargates...now those are cool.
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Old 01-24-2012, 02:14 PM
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Default RE: Truth or Myth about 2.4 antenna

I have had two planes crash in the past two weeks. They both suddenly dipped a wing and headed earthward on final approach to the strip. Wind direction was the opposite direction on second crash so it occurred at opposite end of runway. First crash was from low altitude and I had no chance to try any saving stick movement and I put it down to tip stall of something like that as it occurred at end of turn into runway approach.
The second happened further out and from other end, plane was on straight descent to strip when the problem occurred. This time I had time to try something but found there was no response from any control. It was definitely unbound. Both planes had satellite receivers fitted as per instructions.
I had made a new transmitter case foam interior for my new DX8 and had cut the foam with the antenna straight.
Guess what? I had not bent my antenna.
Thinking about it the landing approach is one time when the straight transmitter antenna is perfectly aligned to plane so all our club who saw the crashes agree with my summation that they were 'pilot error' with the error being not bending the transmitter antenna. Also another club member now remembers having a strange unbind with his DX7 when flying with straight antenna.
Bend it!
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Old 01-24-2012, 02:37 PM
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Default RE: Truth or Myth about 2.4 antenna


Quote:
ORIGINAL: adder

I have had two planes crash in the past two weeks. They both suddenly dipped a wing and headed earthward on final approach to the strip. Wind direction was the opposite direction on second crash so it occurred at opposite end of runway. First crash was from low altitude and I had no chance to try any saving stick movement and I put it down to tip stall of something like that as it occurred at end of turn into runway approach.
The second happened further out and from other end, plane was on straight descent to strip when the problem occurred. This time I had time to try something but found there was no response from any control. It was definitely unbound. Both planes had satellite receivers fitted as per instructions.
I had made a new transmitter case foam interior for my new DX8 and had cut the foam with the antenna straight.
Guess what? I had not bent my antenna.
Thinking about it the landing approach is one time when the straight transmitter antenna is perfectly aligned to plane so all our club who saw the crashes agree with my summation that they were 'pilot error' with the error being not bending the transmitter antenna. Also another club member now remembers having a strange unbind with his DX7 when flying with straight antenna.
Bend it!
I always keep my 2.4 antennas at a 45 deg angle to the side. Straight up is not a problem unless you are pointing it directly at the aircraft. Pointing it up with the aircraft out in front of you should be OK.

When you say the radio became UnBound, do you mean that you had to ReBind it to restore the Link. Generally, when your aircraft becomes unresponsive, it is because the Link is lost between the Tx and the Rx. This could be due to Interference and would result in a Failsafe Event. Depending upon how you set the Failsafe during Binding, it should result in all channels Holding and the Throttle going to Idle, or if you Bound for Preset, all channels would go to their Preset positions.

If your Rx had a Brownout, you would also have no control over the aircraft until the Rx rebooted. With up to date Rx firmware, the Rx should only take a second to reboot. With JR/Spektrum, there is no Failsafe in play during a Brownout or an RX power loss.

Pointing the Tx antenna at the aircraft could cause the Link to be lost, but only for a brief moment.

There should be no loss of Bind.
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Old 01-24-2012, 03:12 PM
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Default RE: Truth or Myth about 2.4 antenna


Quote:
ORIGINAL: Josey Wales

Since this is the direct support forum, how bout we wait and see what Danny has to say ?
It has been years since Danny answered anything in this forum. Right?
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Old 01-24-2012, 08:38 PM
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Default RE: Truth or Myth about 2.4 antenna

Ok I obviously did not explain this position properly. Transmitter in my hands was almost horizontal with antenna pointing slightly up and towards landing model which puts the antenna sharp end perfectly in line with plane. I meant loss of signal which causes receiver to temporarily unbind from tx and which takes a bit too long to re-establish contact, I erroneously assumed readers would understand this. I probably hadn't paid too much attention to "failsafe position" when binding the receiver though. Something to watch in future.
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Old 01-24-2012, 09:29 PM
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Default RE: Truth or Myth about 2.4 antenna


Quote:
ORIGINAL: adder

Ok I obviously did not explain this position properly. Transmitter in my hands was almost horizontal with antenna pointing slightly up and towards landing model which puts the antenna sharp end perfectly in line with plane. I meant loss of signal which causes receiver to temporarily unbind from tx and which takes a bit too long to re-establish contact, I erroneously assumed readers would understand this. I probably hadn't paid too much attention to ''failsafe position'' when binding the receiver though. Something to watch in future.
The important thing to understand is that whether the Tx antenna is Straight or Bent, it should not be pointed directly at the aircraft. Secondly, it is important to get used to using the correct terminology.

When the signal from the Tx to the Rx is interrupted, it is referred to as a lost Link, not UnBind. Pointing the Transmitter antenna at the aircraft can Break the Link between the Tx and Rx

Binding is the process of saving the Unique Transmitter ID to the Receiver. The Receiver will only talk to the Transmitter it is Bound to.

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Old 01-24-2012, 11:49 PM
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Default RE: Truth or Myth about 2.4 antenna

Quote:
Secondly, it is important to get used to using the correct terminology.
Maybe for you!
I'm afraid I'm a laid back Aussie and frankly Scarlet etc. etc.
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Old 01-25-2012, 04:51 AM
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Default RE: Truth or Myth about 2.4 antenna


Quote:
ORIGINAL: adder

Quote:
Secondly, it is important to get used to using the correct terminology.
Maybe for you!
I'm afraid I'm a laid back Aussie and frankly Scarlet etc. etc.
Some of us spend a great deal of time trying to help people find the solutions to their problems. I think if you took the time to search RCU, RCGroups, and Flying Giants, you would find numerous threads that have already discussed the antenna placement issue in great detail. I have seen articles on Horizon Hobbies web site explaining the answer to your question, with pictures and diagrams.

Many people who post on forums like this one misuse the terms Link and Bind. It only leads to misunderstanding and confusion on the part of the person asking the question, the person trying to provide the solution, and anyone following the thread who has a similar problem.

If you are not going to attempt to communicate clearly then perhaps you are not serious about finding an answer to your question and just out for a joy ride.
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Old 01-25-2012, 05:33 AM
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Default RE: Truth or Myth about 2.4 antenna

Pointing your antenna at the plane is no big issue at the ranges we fly, and certainly not on landing approach.

You can read all about dipole antennas and the "cone of silence" theory but I've done testing at very extreme ranges with a datalogger and could find very little difference.

When I say "extreme range" I'm talking large sailplane at the edge of being able to see it.
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Old 01-25-2012, 06:00 AM
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Default RE: Truth or Myth about 2.4 antenna

What he said!
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Old 01-25-2012, 06:04 AM
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Default RE: Truth or Myth about 2.4 antenna


Quote:
ORIGINAL: BarracudaHockey

Pointing your antenna at the plane is no big issue at the ranges we fly, and certainly not on landing approach.

You can read all about dipole antennas and the ''cone of silence'' theory but I've done testing at very extreme ranges with a datalogger and could find very little difference.

When I say ''extreme range'' I'm talking large sailplane at the edge of being able to see it.
Since 2.4 appeared on the scene, I have experienced almost none of the glitching we used to experience all the time with 72Mhz. Of the few instances where there were unexplained phenomena, it most often happened on or near landing approaches.

Horizon specifically cautions about antenna placement.

I use a Flight Logger or Data Logger, as well, but it only reports the number of Fades, Frame Losses, and Holds, but not where in the flight they occurred.

Perhaps with the Telemetry on my DX8 and the STI Module, I can conduct some tests to see if the level of Fades, Frame Losses, and Holds increases when the antenna is pointed directly at the aircraft.
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Old 01-25-2012, 09:33 AM
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Default RE: Truth or Myth about 2.4 antenna


Quote:
ORIGINAL: adder

Quote:
Secondly, it is important to get used to using the correct terminology.
Maybe for you!
I'm afraid I'm a laid back Aussie and frankly Scarlet etc. etc.
With this attitude I now understand the first sentence in post #10 above.
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Old 01-27-2012, 06:30 PM
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Default RE: Truth or Myth about 2.4 antenna

Quote:
Some of us spend a great deal of time trying to help people find the solutions to their problems. I think if you took the time to search RCU, RCGroups, and ****, you would find numerous threads that have already discussed the antenna placement issue in great detail. I have seen articles on Horizon Hobbies web site explaining the answer to your question, with pictures and diagrams.

Many people who post on forums like this one misuse the terms Link and Bind. It only leads to misunderstanding and confusion on the part of the person asking the question, the person trying to provide the solution, and anyone following the thread who has a similar problem.

If you are not going to attempt to communicate clearly then perhaps you are not serious about finding an answer to your question and just out for a joy ride.

Sorry buschbarber but your last post is way out of line and totally inaccurate.

1. I did read RCU forums on the topic , a point you should have picked up on as I added to an existing thread which I found while searching RCU.

2. I DID NOT ask a question.....perhaps if you read my first post you will see there is no ? in it. It was merely an observation to which did not need an answer.

3. Joy ride?? I was trying to help. I did NOT ask a question.

4.I did make a comment about 2 crashes that I thought would be understood by all reasonable people who read them and might prove useful. It was you that took offence to the word bind.

Actually you KNOW you DID understand what I was getting at but chose to chip me when there was no need. I would humbly suggest that you confine you "help" to those who actually ask a question.
It did nothing to advance the thread only annoyed the cr*p out of me. I have no problem with anyone questioning my observation (as BarracudaHocky has) and suggesting another cause but you certainly have not done this, only gone on about the correct terminology of a word that even you understood the meaning of.

The point was..... If your antenna is straight and you hold your transmitter semi horizontal and point it at your model when landing, you might find the receiver loses (bind?? communication, link, signal ) with transmitter and your plane might crash.
With the antenna bent this wont happen as you should NEVER have your model directly overhead.
See no question only an observation.
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Old 01-27-2012, 09:03 PM
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Default RE: Truth or Myth about 2.4 antenna


Quote:
ORIGINAL: adder

Quote:
Some of us spend a great deal of time trying to help people find the solutions to their problems. I think if you took the time to search RCU, RCGroups, and ****, you would find numerous threads that have already discussed the antenna placement issue in great detail. I have seen articles on Horizon Hobbies web site explaining the answer to your question, with pictures and diagrams.

Many people who post on forums like this one misuse the terms Link and Bind. It only leads to misunderstanding and confusion on the part of the person asking the question, the person trying to provide the solution, and anyone following the thread who has a similar problem.

If you are not going to attempt to communicate clearly then perhaps you are not serious about finding an answer to your question and just out for a joy ride.

Sorry buschbarber but your last post is way out of line and totally inaccurate.

1. I did read RCU forums on the topic , a point you should have picked up on as I added to an existing thread which I found while searching RCU.

2. I DID NOT ask a question.....perhaps if you read my first post you will see there is no ? in it. It was merely an observation to which did not need an answer.

3. Joy ride?? I was trying to help. I did NOT ask a question.

4.I did make a comment about 2 crashes that I thought would be understood by all reasonable people who read them and might prove useful. It was you that took offence to the word bind.

Actually you KNOW you DID understand what I was getting at but chose to chip me when there was no need. I would humbly suggest that you confine you ''help'' to those who actually ask a question.
It did nothing to advance the thread only annoyed the cr*p out of me. I have no problem with anyone questioning my observation (as BarracudaHocky has) and suggesting another cause but you certainly have not done this, only gone on about the correct terminology of a word that even you understood the meaning of.

The point was..... If your antenna is straight and you hold your transmitter semi horizontal and point it at your model when landing, you might find the receiver loses (bind?? communication, link, signal ) with transmitter and your plane might crash.
With the antenna bent this wont happen as you should NEVER have your model directly overhead.
See no question only an observation.
Adder - In you post #10, you used the term UnBiind to describe the loss of signal between the Tx and Rx. I replied indicating that was an incorrect use of terminology. You replied and again used the term UnBind referring to the loss of signal between your Tx and Rx.

Misusing these terms is confusing to those trying to help and most importantly to those new to the hobby who frequent these forums looking for answers.

I again pointed out that you were using incorrect terminology.

In post #15, you insinuated that using the correct terminology was only important to me, but not to you.

I could only infer that you were Jerking my Chain and that this was just a big joke to you. Thus, I replied that you must be just out for a joy ride and not serious about the topic.

I have nothing against you personally and I am not interested in attacking anyone. I just want to help resolve the problem posted.

There are occasionally posters who like to Hijack threads and be controversial just to get attention. Your remarks led me to believe you fell into that category.
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