SavantWolf
New Member
Im very new into the quadcopter hobby but theres always been a question that lingered my mind when I built my first two drones: does a receiver with two antennas have a better range than a reciever with one?
Receiver Antenna questions
- Thread starter SavantWolf
- Start date
rosco11
Well-Known Member
Usually, the receivers with a single wire are for micro or mini quads and are very small and light. Honestly, it will still have more range than your 5.8 video transmitter, so a better question is, does it matter? Not for most people.
Absolutely no point in spending 40 to 50 bucks on a fancy x9r long range receiver to go fly in the park when a 15 dollar micro will do the same job and take up 1/3rd the space on your build.
That is if you are talking 2.4ghz and not uhf receivers which often come with one wire too.
Absolutely no point in spending 40 to 50 bucks on a fancy x9r long range receiver to go fly in the park when a 15 dollar micro will do the same job and take up 1/3rd the space on your build.
That is if you are talking 2.4ghz and not uhf receivers which often come with one wire too.
Gyro Doctor
Electronics Tech for over 45 years
There's two antennas because there's simply two antennas and you angle them for the best polarization alignment, THEN there's two antennas because it's a diversity system.
Polarization is the effect that a vertical antenna receives best from another likewise vertical antenna, whereas one being horizontal while the other is vertical diminishes the signal.
Diversity is an active switching mechanism in the receiver that selects the reception from the best of the two antennas. The most common application of this scenario is seen on goggles like FatSharks that have two different styles of antennas on them. Typically one is a directional type (which has increased reception but a narrow beam path) and the other
is a regular mushroom type (average reception in an omnidirectional beam path).
In a non-diversity system there's no real range gain, just an improvement of the signal quality and less reduction of range from optimal alignment by virtue of the fact that at which ever attitude the quad is in the antennas will still be roughly in alignment. Diversity systems DO offer range gain because the narrow beamed directional antennas have further range than omnidirectional ones.
Chuck
Well-Known Member
I'm looking at the FlySky i6 transmitter and receiver combination. The receiver has two antennae. What is the best (and safest) method to mount them within a quad frame, to avoid damage to them, while not degrading their effectiveness?
Gyro Doctor
Electronics Tech for over 45 years
That depends upon the quad it's being mounted upon, like whether or not it's a plastic X-bodied frame versus a carbon racing frame.
In either scenario you want a roughly ninety degree angle between the two so that one or the other wires is in alignment with your TX's antenna at any given point.
You cannot mount them within the frame of a carbon quad but you can with a plastic one. I've seen one wire running down the landing gear while another is laying in an
arm or just laying inside the belly of plastic X-bodies and that seemed to work rather well. You'll probably want to add a spot or two of hotglue to keep them in place.
For carbon frames the antennas are usually just sticking up from the top and held in place by being inside straws or wired to stiff "zip-ties".
There are also premade guides you can buy like these: https://www.ebay.com/i/281661222941?chn=ps&dispItem=1
rosco11
Well-Known Member
I can only tell you what i do and have had a lot of success with. Success being i have never had one ripped off or damaged.
I run mine down the arm along the upper inside edge and tape it there with electrical tape. Easy on, easy off and insulated in a crash. Being an inside edge, between the front and back arm, it rarely gets damage and on the top side, you do not have to worry about hard landings.
as far as "cannot mount them along the frame on a carbon fiber frame..." All of mine have been. Just run a strip of electrical tape underneath the wire and another on top to hold it in place. It is not any more likely to ground out than your arm mounted esc that way. I have the bare silver part hanging down below the motors. The props insure they will always be pushed down when flying.
The cool looking top mounted kind as well as those with the fancy 3d printed holders and such do not hold up well to inverted landings. A common thing when starting out. I run my receiver antenna along the arms and the transmitter antenna straight out of the back of the quad for the same reason. Anything sticking up is going to take damage in a crash.
And remember, your limit is set by the 5.8 video transmitter, so don't sweat not getting optimal range out of your receiver. Even impaired it is still likely to get more distance than the vtx.
In the short term, the flysky is cheaper. But if you plan on sticking with it, you might want to take a hard look at the Frsky transmitters. They are getting to be dominate in the market. Bigger selection of receivers and a lot of the All In One stacks have frsky receivers built in.
I run mine down the arm along the upper inside edge and tape it there with electrical tape. Easy on, easy off and insulated in a crash. Being an inside edge, between the front and back arm, it rarely gets damage and on the top side, you do not have to worry about hard landings.
as far as "cannot mount them along the frame on a carbon fiber frame..." All of mine have been. Just run a strip of electrical tape underneath the wire and another on top to hold it in place. It is not any more likely to ground out than your arm mounted esc that way. I have the bare silver part hanging down below the motors. The props insure they will always be pushed down when flying.
The cool looking top mounted kind as well as those with the fancy 3d printed holders and such do not hold up well to inverted landings. A common thing when starting out. I run my receiver antenna along the arms and the transmitter antenna straight out of the back of the quad for the same reason. Anything sticking up is going to take damage in a crash.
And remember, your limit is set by the 5.8 video transmitter, so don't sweat not getting optimal range out of your receiver. Even impaired it is still likely to get more distance than the vtx.
In the short term, the flysky is cheaper. But if you plan on sticking with it, you might want to take a hard look at the Frsky transmitters. They are getting to be dominate in the market. Bigger selection of receivers and a lot of the All In One stacks have frsky receivers built in.
mozquito1
Well-Known Member
It's a good choice. Upgrade on range. What fcb have you got.
The best way on paper says are a 90° angle from the vertical axis, preferably to the rear of the craft. But I place one at the top back near the omni & one underneath near the front is placed down & hung up when not in use so the antenna is straight down when flying at a 45°. So both antenna are at poles to each other.
I can see the math in the 90, but would rather have that clean bottom antenna.
I don't go beyond 200-300' either way but have tested the range to the fullest extent of my biggest flying area 900m & only ever had 1 dis-arm. I got an A8S micro rx.
It's tiny & has good range for its size. Small enough for a 120-30+ frames.
It may be bad placing but it works.
I can hang time all day no worries.
Fsi6 has been a rock. The only reason I want to change Tx to pretty much the same one in terms of compatibility,
Is the turnigy evolution for its size.
Especially now I've found I can't wear fatsharks or Skyzones as my ipd is 70.
So it's all crosseyed.
So I need the space in my bag for quanum V2 and will get a immersionRC duo5800 V4.1.
Gyro Doctor
Electronics Tech for over 45 years
Please note that I said WITHIN (as in inside) the frame which is quite different from "alongside" the frame which (although that does work) deforms the radiation pattern, as any carbon frame acts as an obstacle and creates a "flat spot" or "dead zone" in the otherwise circular reception envelope.
I'm not talking about electrical conductivity and insulation here but aspects of RF energy absorption, blocking, and reflection.
QuadKid
Noth'in Like a Flat Top
"Yes they do. Line em up at 90° for best coverage"
Absolutely they should be at a 90º angle whether that be a V or an L also the TX ( Controller ) Antenna should be positioned horizontally not vertically id possible, one more thing to consider to get the best range is to make sure the inner wire of the antenna is exposed typically 32-37mm from the end. Antennas are made of an inner receiving wire and an outer coaxial shield, carefully cut the outer insulation away exposing the coaxial shield, carefully remove the shielded braided wire to expose inner RX wire.
Absolutely they should be at a 90º angle whether that be a V or an L also the TX ( Controller ) Antenna should be positioned horizontally not vertically id possible, one more thing to consider to get the best range is to make sure the inner wire of the antenna is exposed typically 32-37mm from the end. Antennas are made of an inner receiving wire and an outer coaxial shield, carefully cut the outer insulation away exposing the coaxial shield, carefully remove the shielded braided wire to expose inner RX wire.
Gyro Doctor
Electronics Tech for over 45 years
The amount of exposed inner wire in a coaxial cable when used for an antenna is predetermined by the manufacturer.You DO NOT monkey around with exposing more inner wire because doing so simply detunes your antenna.
The ELECTRICAL length of the antenna (not it's physical length) is the primary goal, which varies with the TX, the attachment method to the TX,
the type of coax used, and other factors.
I could get into several more technical reasons and include links to explain the electronics, physics, and math backing up my statement but suffice to
say you should never hack on the antenna wires coming out of the receiver
QuadKid
Noth'in Like a Flat Top
Yup, but I have prop nipped antenna wires during a crash and cut them to even lengths then exposed the inner RX wire to manufactures recommendation (IE: FrySky XSR 4 = 32mm) and have had no ill effects, fly's just fine. Beats replacing the RX or waiting 3 weeks to get from China!
Gyro Doctor
Electronics Tech for over 45 years
... Well now, THAT's completely a horse of a different color then ... lol ... well done !