WattFlyer RC Electric Flight Forums - Discuss radio control eflight

WattFlyer RC Electric Flight Forums - Discuss radio control eflight (http://www.Wattflyer.com/forums/index.php)
-   General Electric Discussions (http://www.Wattflyer.com/forums/forumdisplay.php?f=3)
-   -   antenna bend (http://www.Wattflyer.com/forums/showthread.php?t=73281)

sidybee 03-04-2014 01:23 AM

antenna bend
 
why are the antenna bendable on the flysky radios 2.4 ghz .
or any of those radios.........maybe this answer will answer my other problem......:)

xmech2k 03-04-2014 01:36 AM

From what the experts say, the strongest signal comes out the sides of the antennae, the weakest out the top and bottom. Imagine a giant donut placed over your antennae. So put your antennae in a way it's never pointing at the plane. I put it straight up.

mclarkson 03-04-2014 02:55 AM

That's pretty much my understanding as well. The worst reception possible is when the Tx and Rx antennae are pointing directly at each other.

fhhuber 03-04-2014 03:03 AM

So, in theory the best orientation for the TX antenna is with it parallel to the top of the TX case.

But that is for best range. There is no real "cone of silence" its just the cone of weakest signal. That cone is still good enough for most line of sight flying.

sidybee 03-04-2014 03:13 AM

ok thats what ive read as well . that being said thats probably my problem that i posted in a different thread. i got to thinking today while out riding my scoot. that would explain the lose of control i had but the motor never shut down just no control movement from the sticks. but i cant remember if i lifted up the radio at that time that i regained the stick control. im going out tomorrow and test this. but im thinking that that may have been it cause i know for sure i was pointing the antenna at the plane..........i think when i ride my scoot get out and be free from the world.......

kyleservicetech 03-04-2014 03:17 AM

Quote:

Originally Posted by sidybee (Post 941429)
why are the antenna bendable on the flysky radios 2.4 ghz .
or any of those radios.........maybe this answer will answer my other problem......:)

The signal radiated from those 2.4 Ghz transmitters is "Strongest" perpendicular to the antenna orientation, and weakest off the "Tip" of the antenna.

So, you might see only 50% range if you point your transmitter directly at your model. That would reduce your range from 4 miles to 2 miles. Assuming a full range radio system, and a decent radio brand.

As for placing your transmitter antenna "Sideways", that will also reduce your range. (The 2.4 Ghz transmitted radio wave is polarized. Kind of like polarized sun glasses.) This is the primary reason some 2.4 Ghz receivers have a pair of antennas, one is pointing up and down, the other is pointing left to right. This allows at least one receiver antenna to be "Face On" to however your transmitter antenna and your model airplane is orientated.

So, even if you do everything wrong on a full range 2.4 Ghz radio system with antenna orientation, your radio range is still much farther than the visibility of your model.

Take a look at a spectrum analyzer that showed some results of this stuff.
http://www.wattflyer.com/forums/showthread.php?t=72719

I've got a Spektrum radio system, with the Spektrum signal level monitor. After a dozen flights, with zero signal loss of any type on a giant scale model, that monitor is resting in one of my Spektrum radio drawers.

mclarkson 03-04-2014 03:27 AM

I managed to 'shoot down' my own plane one time by pointing my antenna directly at it (without meaning to.) I was maybe 750 feet / 230 meters away at the time. Honestly, that plane is rarely that far away in the first place.

sidybee 03-04-2014 03:34 AM

kyle i lost control use at around 300 feet then i got full use of controls just before it got to me right around 15 feet the plane was never far from me most is 2 or 300 feet flew great way up, close to earth is where i had problems.. but im going out tomorrow and test this theory. just to satisfy
my curiosity about this.......i miss my fm radio never had a problem ever.
of coarse never flew electrics either.this electric stuff is kinda making me wanna go back to glow at least it worked every time. but im stubborn ill make this work one way or another hahahaha

kyleservicetech 03-04-2014 03:40 AM

Quote:

Originally Posted by mclarkson (Post 941449)
I managed to 'shoot down' my own plane one time by pointing my antenna directly at it (without meaning to.) I was maybe 750 feet / 230 meters away at the time. Honestly, that plane is rarely that far away in the first place.

I've got the Spektrum DX8 transmitter with their two receiver AR7000 units. And, the transmitter was pointed directly at a giant scale model that was over 1100 feet straight up. Doing that had no effect on control of the model.

kyleservicetech 03-04-2014 03:45 AM

Quote:

Originally Posted by sidybee (Post 941452)
kyle i lost control use at around 300 feet then i got full use of controls just before it got to me right around 15 feet the plane was never far from me most is 2 or 300 feet flew great way up, close to earth is where i had problems.. but im going out tomorrow and test this theory. just to satisfy
my curiosity about this.......i miss my fm radio never had a problem ever.
of coarse never flew electrics either.this electric stuff is kinda making me wanna go back to glow at least it worked every time. but im stubborn ill make this work one way or another hahahaha

Man, that really sounds like you had a 5 volt linear voltage regulator in your ESC overheat and shut down. This kills receiver and servo operation. And, after the regulator cooled off, it started working again, restoring radio operation. It takes those linear regulators about 30 seconds or so to cool off, and restart.

I've seen this happen more than once at our club field. IMHO, I'll NEVER use an ESC with a linear voltage regulator for receiver/servo power on any LiPo battery with more than two cells, and more than two servos.

One way out of it, is to use one of those uBEC's such as Castle Creations 10 Amp Switching Battery Elimination Circuit. They go for about $25 or so, and will power any model up to my two 3000 Watt Giant scale models. There are eight of them in my various electric models.

http://www.rcplanet.com/CASTLE_BEC_1...FcU-MgodIWAA8g

BEC Linear Current Rating
http://www.wattflyer.com/forums/showthread.php?t=63779

sidybee 03-04-2014 03:54 AM

i got an ubec thats just waiting to get installed if this does not works out.
your the third person to tell me this but everybody says the motor will shut off too.. thats not the case with mine the motor stay running i cant shut it down i have no control use. at all but that motor is humming away...
ill go out and try a flight then if it happens again ill install the ubec and try that too. im afrain of getting too heavy im just flying a speedy bee and im pretty heavy now................

xmech2k 03-04-2014 08:17 AM

I speak Spektrum, but do the FrSky (or however it's spelled) rx's have a failsafe mode? With the Spektrums, you bind the rx, then after your plane is all setup, you can re-bind. If your rx ever losses signal, it moves all the controls to what they were at the last bind, probably neutral and zero throttle. Maybe your rx had something like it? Though I wonder if it's actually possible to bind when the tx throttle isn't all the way down. And I don't know how the rx behaves in a brownout in respect to the esc, if a brownout was the case.

Panther 03-04-2014 10:08 AM

FrSky all have failsafe.... wouldn't be without it.
sidybee If your linear bec shuts down your motor will keep going but your receiver wont.

sidybee 03-04-2014 09:07 PM

well i got in some flying today a little windy but i flew anyway. not one glitch not one no control , nothing at all....all three battery's latter and all is good very good, things i did to plane before i left,,,,......,moved antenna to vertical so its sticking almost straight out of the plane,,,,,,,,,,,,i twisted the bec wires 5 or 6 turns then connected that to receiver,,,,,,, ,, drove 20 miles to and area that has no telephone wires or radio towers or nothing just wide open space open ranch land prob 200 acres flat open ground..... could not beleive how great i flew today(should have brought the charger) so (1) could have been antenna (it was in side the plane but pointed away from electrics.....(2) that twisted bec wire (it had a glitch before i twisted it no more glitch after that) (3) wide open space and nothing to interfere with radio signals. batterys were 2 @2200 20 c....1 2 2200 40c about thirty minutes flight time maybe a bit more the wind was pretty good out there.........tomarrow if its not so windy ill go back to where i had problems flying and fly there for a test,,flat 40 acres surrounded by nut fruit trees, radio tower about 2 miles away,,, big buildings were house's ect 3/4 mile maybe closer to 1/2 mile away power lines right behind me 10 feet will do test there and see........

sidybee 03-04-2014 09:09 PM

Quote:

Originally Posted by Panther (Post 941477)
FrSky all have failsafe.... wouldn't be without it.
sidybee If your linear bec shuts down your motor will keep going but your receiver wont.

and this is exactly what has been going on too.... thank you

kyleservicetech 03-04-2014 10:30 PM

Quote:

Originally Posted by xmech2k (Post 941475)
I speak Spektrum, but do the FrSky (or however it's spelled) rx's have a failsafe mode? With the Spektrums, you bind the rx, then after your plane is all setup, you can re-bind. If your rx ever losses signal, it moves all the controls to what they were at the last bind, probably neutral and zero throttle. Maybe your rx had something like it? Though I wonder if it's actually possible to bind when the tx throttle isn't all the way down. And I don't know how the rx behaves in a brownout in respect to the esc, if a brownout was the case.

Just a note.

Fail safe is a function where the receiver sends the attached servos to a predetermined position when the receiver looses signal from the transmitter.

If your ESC's Linear BEC shuts down, killing all power to the receiver, that fail safe feature can not function.

kyleservicetech 03-04-2014 10:33 PM

Quote:

Originally Posted by sidybee (Post 941521)
well i got in some flying today a little windy but i flew anyway. not one glitch not one no control , nothing at all....all three battery's latter and all is good very good, things i did to plane before i left,,,,......,moved antenna to vertical so its sticking almost straight out of the plane,,,,,,,,,,,,i twisted the bec wires 5 or 6 turns then connected that to receiver,,,,,,, ,, drove 20 miles to and area that has no telephone wires or radio towers or nothing just wide open space open ranch land prob 200 acres flat open ground..... could not beleive how great i flew today(should have brought the charger) so (1) could have been antenna (it was in side the plane but pointed away from electrics.....(2) that twisted bec wire (it had a glitch before i twisted it no more glitch after that) (3) wide open space and nothing to interfere with radio signals. batterys were 2 @2200 20 c....1 2 2200 40c about thirty minutes flight time maybe a bit more the wind was pretty good out there.........tomarrow if its not so windy ill go back to where i had problems flying and fly there for a test,,flat 40 acres surrounded by nut fruit trees, radio tower about 2 miles away,,, big buildings were house's ect 3/4 mile maybe closer to 1/2 mile away power lines right behind me 10 feet will do test there and see........

Let us know how it works where you were having problems in the past. These 2.4 Ghz radios usually are pretty much unaffected by local radio towers and so on. Microwave towers??? Who knows.

I've got a 2.4 Ghz Frequency scanner, might just take it to the local Cellphone tower, and see if it picks up anything. :confused: Of course that would be more an indication of the quality of the scanners circuitry, than that of our 2.4 Ghz receivers. :D

sidybee 03-05-2014 12:49 AM

ya and i also flew with the antenna bent too on the radio, still no afect and also flew with it pointed straight out same thing, then i pointed it straight at the plane same thing ,,then i put it in the truck of the car same thing... so now i think that wire that i twisted had something to do with it and maybe the way i stuck the receiver antenna too.
ill go to the problem field and find out for sure though im just afrain if i lose control again it might fly into a car or truck before i can get control again.....

ya it would be if you could do that and test if there are things from those towers or not.........thanks

Karnsy 03-07-2014 01:17 AM

What about the radios @2.4 that are a fix stem antenna ?

kyleservicetech 03-07-2014 01:26 AM

Quote:

Originally Posted by Karnsy (Post 941741)
What about the radios @2.4 that are a fix stem antenna ?

Should not be a problem, even with the transmitter antenna pointed at the model, your range for a full range receiver will still be long out of sight.

fhhuber 03-07-2014 04:48 AM

The range limit is normally RX sensitivity.

Turner 03-07-2014 07:23 AM

Quote:

Originally Posted by Karnsy (Post 941741)
What about the radios @2.4 that are a fix stem antenna ?

If it just has a single antenna then it still applies. Don't point the antenna directly at the aircraft, especially at a distance.


All times are GMT +1. The time now is 04:09 AM.

Powered by: vBulletin
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright 2005 WattfFlyer.com
RCU Eflight HQ

Page generated in 0.09386 seconds with 13 queries