2.4ghz Control Megathread - Spektrum, Futaba, FrSky, etc

[aeryck]

Thanks to my brother I was able to do some extensive range testing with my DX8 radio.

He lives on a smallish inland lake in MI, so while I had the transmitter on one shore, he drove around to the other shore with the plane, which is about 1.5 miles LOS across the water.

With a DX8 radio and an AR8000 receiver (with satellite rx) in DSMX mode, we had a solid RC link across the water at 1.5mi range with both the plane and Tx about 6' above ground level. If either the plane or the Tx got closer to the ground, we started getting Rx holds.

All this was performed with a 500mW 900MHz video transmitter in use as well, as we were trying to determine what effect, if any, the video transmitter would have on reduced RC range. We performed the test both with the video tx powered on and without it, and there was no visible difference in the results.

I'm going to repeat the test with a TM1000 telemetry module installed as well, to see if the telemetry works that far out, and if it does, it will give me detailed stats of the spektrum link including dropped frames, holds, and antenna fades.

I know Spektrum (or 2.4GHz in general) isn't the first choice for an RC link with FPV, however I already had the radio and will be investing in a UHF system before I try for any kind of long distance. I just wanted to get a real-world idea of any interference issues. As it stands right now the RC link has more range than the video link (Stock whip antennas on both the video Tx and Rx) so I'd start to lose video long before the RC signal lost.

I plan on doing my first few FPV flights with my brother spotting 3rd person on a buddy box, so if I start getting out of his visual range he can take over and bring me back around if I start getting disoriented.

Always looking for recommendations from the more experienced FPV pilots, so any feedback is welcome (aside from "don't use 2.4GHz radios with FPV!", since I already know that. =] )

[Asomaro]

Thanks for the info, very interesting and I would like to hear more details (telemetry data) when you have it.

Cheers,

[PDXDave]

Thanks to my brother I was able to do some extensive range testing with my DX8 radio.

He lives on a smallish inland lake in MI, so while I had the transmitter on one shore, he drove around to the other shore with the plane, which is about 1.5 miles LOS across the water.

With a DX8 radio and an AR8000 receiver (with satellite rx) in DSMX mode, we had a solid RC link across the water at 1.5mi range with both the plane and Tx about 6' above ground level. If either the plane or the Tx got closer to the ground, we started getting Rx holds.

All this was performed with a 500mW 900MHz video transmitter in use as well, as we were trying to determine what effect, if any, the video transmitter would have on reduced RC range. We performed the test both with the video tx powered on and without it, and there was no visible difference in the results.

I'm going to repeat the test with a TM1000 telemetry module installed as well, to see if the telemetry works that far out, and if it does, it will give me detailed stats of the spektrum link including dropped frames, holds, and antenna fades.

I know Spektrum (or 2.4GHz in general) isn't the first choice for an RC link with FPV, however I already had the radio and will be investing in a UHF system before I try for any kind of long distance. I just wanted to get a real-world idea of any interference issues. As it stands right now the RC link has more range than the video link (Stock whip antennas on both the video Tx and Rx) so I'd start to lose video long before the RC signal lost.

I plan on doing my first few FPV flights with my brother spotting 3rd person on a buddy box, so if I start getting out of his visual range he can take over and bring me back around if I start getting disoriented.

Always looking for recommendations from the more experienced FPV pilots, so any feedback is welcome (aside from "don't use 2.4GHz radios with FPV!", since I already know that. =] )

Hi Aeryck,

I know this is an old post, but I wanted to check in and see if you've got more you can add on this. I've got a DX8 and have only been operating within 2,000' but so many people on these boards say not to use a Spektrum radio for FPV and wanted to hear from someone with firsthand experience. Thanks.

[Pelagic Pilot]

Hey Dave

I am down in Grants Pass, everyone says dont use spektrum for FPV, but for shorter range helicopter FPV I have had no problems at all. My DX6i has tested solid to 1/4 mile but ran out of room to walk further away. Just that in itself gives you a half mile circle to play in. So for starters I say go for it.

[aeryck]

Hi Aeryck,

I know this is an old post, but I wanted to check in and see if you've got more you can add on this. I've got a DX8 and have only been operating within 2,000' but so many people on these boards say not to use a Spektrum radio for FPV and wanted to hear from someone with firsthand experience. Thanks.

The latest range tests on the lake revealed that the tm1000 telemetry module does not have the range to make it back to the tx at 1.5mi, but at that distance, with the video gear running, i was able to power up the radio and find the receiver within seconds.

I hear the "dont use spektrum" story all too often but what i never hear with it is facts and solid information. I had a dsm2 lockout at 400', and have never had a dsmx lockout at up to 2500' while flying fpv. I think the biggest difference, that always seems to be omitted from spektrum horror stories, is whether or not the system was properly filtered and separated. My 400' lockout did not have any filters on the vtx; by adding a low pass filter on my vtx i now have no difference between a video on and a video off range check.

[PDXDave]

Hey Dave

I am down in Grants Pass, everyone says dont use spektrum for FPV, but for shorter range helicopter FPV I have had no problems at all. My DX6i has tested solid to 1/4 mile but ran out of room to walk further away. Just that in itself gives you a half mile circle to play in. So for starters I say go for it.

Thanks Pelagic -- I appreciate the data. I'm suprised at how many Mossbacks I've seen on this board! You wouldn't think FPV in the rain would hold great appeal, but apparently it does. I'm going to do some more organized testing this weekend (weather permitting), so hopefully I'll have something to share back.

[PDXDave]

The latest range tests on the lake revealed that the tm1000 telemetry module does not have the range to make it back to the tx at 1.5mi, but at that distance, with the video gear running, i was able to power up the radio and find the receiver within seconds.

I hear the "dont use spektrum" story all too often but what i never hear with it is facts and solid information. I had a dsm2 lockout at 400', and have never had a dsmx lockout at up to 2500' while flying fpv. I think the biggest difference, that always seems to be omitted from spektrum horror stories, is whether or not the system was properly filtered and separated. My 400' lockout did not have any filters on the vtx; by adding a low pass filter on my vtx i now have no difference between a video on and a video off range check.

Thanks Aeryck! I'll look into getting a low pass filter -- sounds like the kind of thing RMRC would carry.

Another thing the "don't use Spektrum" crowd doesn't seem to take into account is the type of flying you're doing. If a person wants to go out a number of miles (or wants to work up to that) with flawless video, then Spektrum probably isn't the best solution. But, to use a personal example, if all I want to do is buzz around over my back 40 as an alternative to regular LOS flying at my club, a long-range UHF system seems like overkill. Know what I mean? Thanks again.

[londonguy]

Another thing the "don't use Spektrum" crowd doesn't seem to take into account is the type of flying you're doing. If a person wants to go out a number of miles (or wants to work up to that) with flawless video, then Spektrum probably isn't the best solution. But, to use a personal example, if all I want to do is buzz around over my back 40 as an alternative to regular LOS flying at my club, a long-range UHF system seems like overkill. Know what I mean? Thanks again.

I'm part of the don't use spectrum crowd but that's because I'm a Futaba fanboy...

That being said I flow 2.4ghz FASST link with FPV for a little bit, had a few lock outs but in the end you know the limitations of it and depending on the flying you are doing it may be perfectly acceptable. Anything up to 1km should be safe with most 2.4 systems.

I've got a tricoper in the works and I'll be leaving 2.4ghz on that because I don't intend to fly my tri long range, less than 1km, if not much less.

[PDXDave]

I'm part of the don't use spectrum crowd but that's because I'm a Futaba fanboy...

That being said I flow 2.4ghz FASST link with FPV for a little bit, had a few lock outs but in the end you know the limitations of it and depending on the flying you are doing it may be perfectly acceptable. Anything up to 1km should be safe with most 2.4 systems.

I've got a tricoper in the works and I'll be leaving 2.4ghz on that because I don't intend to fly my tri long range, less than 1km, if not much less.

Good info -- thanks. I've got an 8FG in addition to my DX8, so I can't go solidly "fanboy" to either camp. I like the Futaba quite a bit for its ergonomics and flight response. To me, the Spektrum much easier to program, but the biggest thing is its telemetry. Being able to have flight pack voltage, RSSI, altitude, airspeed, etc on the tx screen instead of being overlaid on the video is a big plus for what I'm doing (testing small airborne cameras our company makes). Honestly, if I knew of a way to get that data from the Futaba system I probably wouldn't be considering the DX8 for FPV and would use it for my sport planes.

[sim_io]

What ever floats your boat man, if you range test it with the 900mhz vtx on at ground level then you should be safe in the air. The issue is that new people that come in to the hobby usually have a 2.4Ghz Spektrum radio but its not the frequency its their lack of knowledge and testing.

I still fly 72Mhz on my trusty Corona receiver. I know when I turn on that 700mw 72Mhz 9c transmitter the signal is traveling miles and miles out with great coverage, and I know if I fly low that I don't have to worry until the video goes bad.