Transmitter range

OK. I didn’t expect solid 500 meter range from a $140 toy. But I thought I might get a little farther than 50 meters out at 30 meters altitude. It is cutting out even before the wifi telemetry to my phone does. Where is the weakest link here?

Should I try to bind one of my other DSM transmitters? I do like the idea of the cheap compact transmitter I can tuck in my bag with the cheap drone, and the telemetry is also handy even if it’s just tones.

Should I try relocating the receiving antenna? It looks like it might be in one of the arms and quite close to the signal-sucking/noise generating motor wires. I’m sure support for a satellite/diversity receiver would be far too much to ask.

Has anyone experimented with getting better range? I don’t expect the moon, but it would be nice to be able test/demonstrate the ability to fly a few waypoints without it entering failsafe mode when it gets to the far side of my yard and I am reluctant to give up the security of the receiver failsafe setting.


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I had a flyaway with the SV .I’m trying to understand why?The transmitter disconnected I believe at about 40 meters.The Sv continued to fly away and the SV app did not respond to return to home or phone.What is suppose to happen(stock) when it disconnects, ie return home?Beep?lights alternate.
I had previously been flying with Qground control. I had turned off the geo fence in app to fly longer missions where I had no transmitter control after 40 meters.The transmitter would always connect when the SV was within range. Did Qground control possibly change the stock SV functionality?

Unless you also disabled radio failsafe (besides fence), it should have initiated an RTL on radio loss (or land if GPS was bad), . Where you able to recover it? Log would help find out what happened.

No, its in a snowcovered field. I have ordered another SV and also a locater beaper.

Its sounds like I may have turned off Radio fail safe to be able to fly my QGC missions that where up to 1500 feet away.

Also when flying with original SV app my thought was that the stock parameters were reloaded into the SV?

If this is not true I will need to change safety parameters in QGC mission planner back to original and download to SV.

Please confirm if this is correct?


I don’t think the app resets parameters, but could be wrong. (I don’t use it). I’ll check …

no, the app doesn’t reset any parameters
Regarding TX range, a DF log may give some clues. We log a lot of information about the radio.

I too saw the very limited range the SV but it returned when signal was lost. Curious, I opened the tx and surprised to find the antenna a separate item from the main controller board with a connector just as an internal laptop wireless card. It attaches to a small flat board probably with the same copper traces all other toy drone tx boards use. (Foam tape holds it to inside of tx) The fake plastic antenna is removable and appears a flat piece of plastic could be cut to fit and a 2.4ghz dipole added. I haven’t tried a mod yet as I can build and fix electronic boards but have very little knowledge of antenna.
In thinking about it, wireless cards in a laptop have a primary and secondary wire that run up to and around the LCD screen. I may try removing the wire from a old laptop, connect it in the tx, make a light weight “X” frame the size of the screen and wrap the wire around it. Logs from my last flight should show if there was an improvement.

I’m new to all of this so I’m still learning. I did notice my SV2450 having a max of 155 feet in altitude right out of the box. Within 2 days I did the firmware updates etc. After the updates my SV only flies up to 132 feet max altitude and have had 2 fly aways.

Do you think the updates are causing the problem? I’ve done a factory reset, but the problem is still there. Not sure if factory reset worked or not because I’ve seen others on the blog with reset problems.

What do you mean, fly aways?

Fly aways - doesn’t respond to transmitter every time and goes off out of range and lands.

As DronePilot_Flyby mentioned the antenna is connected to a short piece of coax which is connected to a micro RF connector. The question for me is which micro RF connector is it? I’m guessing U.FL or MHF. But that is only a guess as I have never worked with micro RF connectors before. As soon as we find out the type of connector then we can simply order a pigtail/SMA adapter and attach it to an external panel antenna for a greatly improved range.

Sounds like failsafe kicked in, with loss of GPS (hence landing vs RTL). Did you try switching to alt hold? If you did and it was still not responding then must’ve been loss of RC too. A log would help to figure it out.

James, looks like it’s an IPX micro RF connector, which according to this would be 100% compatible with Hirose U.FL

Same here . . . 134.1 ft is my maximum altitude.
Any way to tweak this?
70 degree temp and no wind.

Geofence parameters can be adjusted to change this.


Wondering if there was ever a conclusion to this thread? What kind of range should we be expecting?
My Journey seems to be limited to around 50m before RTL kicks in or I lose control.
I have been wondering about using a 5v USB battery pack as an alternate to 3xAAA batteries. Would that possibly improve the range performance?
How about adding an external antenna? Anyone have good results with this?
I have the DataFlash files from my flights. Is RSSI the parameter to look at? What range should this normally be?


As Matt said, you can adjust Geofencing to help a bit. In “general” the default geofence parameters will likely kick in well before the Tx gets out of range…but i personally had a lot of problems with Tx range on my 2450…even after disabling geofence (not recommended).

What I did was modify this value BRD_RADIO_TXMAX = 8 (it defaults to 4)

This will help. After doing this, I could fly my SV beyond LOS. Again, not recommended lol. (or legal?)

Thanks for the feedback. Yesterday I tried doing a more structured test.
Using freshly charged NiMH batteries or new alkaline batteries I was always having RTH kick in at a range of about 120’. I have the BRD_RADIO_TXMAX set to 7, so I will try again at 8.
FPV to the app also failed at around this distance.
I was looking at the RSSI number from the DATAFLASH. I was wondering what other users see as typical RSSI for a given distance?


You need to look at exactly what is kicking in. Sounds like you have the Fence kicking in, not the radio failsafe. You can look at the logs to see which is kicking in, or connect to the SV with Mission Planner on a laptop, or connect using Tower or QGroundControl app and see what message is being displayed when the RTH occurs.

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HI @lordneeko

Thanks for your input. I have the Dataflash file from the flight and am looking at it in MP. I am not quite sure what parameters to review to figure out if it was geo fence or radio failsafe.

My geo fence enable is set to 0 (disable)
fence_radius set to 100 (assume meters?)

I have tried to upload a copy of the log. Would you be able to have a look and let me know?