1.3 Ghz downlink with 2.4Ghz radio

[emeraldheli]

As 900 Mhz is illegal in many EU countries this is available under license. http://www.rangevideo.com/index.php?main_page=index&cPath=35_36
Has anyone any experience of this with a 2.4 Radio? Any other suggestions appreciated.

Thanks in anticipation

[Beaver Rat]

I believe 1.3Ghz is illegal in the USA but 900mhz is legal.

[Efliernz]

I run the Rangevideo 300mW 1.3G radio with two 2.4G on the same machine - 1 for heli and 1 for camera. I am looking at running two 1.3G soon - at each end of the heli's camera u/c.

[emeraldheli]

Thanks for replies,

Beaver Rat,
Sorry, I should have clarified that I am based in Europe so I am looking for an alternative to 900Mhz to use with a Heli driven 2.4 radio.

Eflienz,
Interesting, I take it there are no range issues or other drawbacks with this setup. What are the benefits of running two 1.3's?

[Efliernz]

I use a Trex-600 with a tilt cam mount and/or AskmanAP tilt/pan. My camera operator uses a 7" monitor to look at the vid downlink from the camera - and guide the cam.
I am experimenting with a fpv-style camera facing forwards, with a downlink to my modified eyetops. When flying up high (300-400') and/or straight above you, a level hover is very differcult. This setup will let me look at the eyetop lcd and as long as the horizon is level and in the middle, I am likely to be sort-of level. Purely for safety reasons. I don't intend to fly fpv out of eyesight range. I think my insurer might have problems with that (and our equiv to FAA). That is the gap between a RPV and a model heli in my country.
There should be no reason that I cant run two separate 1.3 downlinks. I maintain careful physical separation on the model and from the 2.4g rx's on the model.

Experiment WITHOUT the camera on boeard. One less thing to buy if is doesn't test well!!!

[Wenlock]

As 900 Mhz is illegal in many EU countries this is available under license. http://www.rangevideo.com/index.php?main_page=index&cPath=35_36
Has anyone any experience of this with a 2.4 Radio? Any other suggestions appreciated.

Thanks in anticipation

I don't know where you are in Europe, but in the UK this RangeVideo transmitter may be legal if you have a radio amateur's licence. I'd be surprised if you can legally use one of these to transmit from the air even with a licence (someone with more knowledge of UK radio amateur licences may correct me).

It's definitely illegal in the UK (and probably elsewhere in the EU) without a licence. The only "licence-free" frequency that I know of in this band is 1394MHz, and I think this frequency is specific to the UK. Lightweight 1394 transmitters are almost impossible to find, they all seem to be high power (500mW with correspondingly heavy power requirements) and highly ruggedised (i.e. heavy).

At the moment I don't know of any legal way to transmit a video downlink if you're a) using 2.4GHz R/C and b) in the EU. If someone knows how to do it, I'd love to hear about it!

[emeraldheli]

Wenlock,

I have been in communication with 'Comreg' the regulatory authority for communications in Ireland where I am based. Both 900 Mhz and 1.3 Ghz have been deemed illegal for RC use as they are assigned to Cellphone network and Aviation.
They pointed me in the direction of 2.4 Ghz and 5.8 Ghz which are licence exempt, however the usage and performance of the devices may be deemed illegal if they exceed certain power criteria. I have submitted the specifications of the video downlink and am reasonably confident that it will fall within the low power SRD category. In my conversations with the officer there was no suggestion that the transmission of a video downlink with approved devices was illegal. However, I await written confirmation and approval.

[R-4-L]

A note about 900mhz systems with 2.4ghz

My radio on the helicopter is Futaba FASST 2.4ghz 14channel system, however, when i ordered the mount (helicam MarkIV) it came with 6ch Futaba 2.4Ghz system.

now check this out:

when I connect the 900mhz Transmitter with a battery (ON) all Mount Servos start to move in one direction and keep on moving ofcourse coz they are 360 modified. and when i disconnect battery from transmitter everything stops.

NOW, i replaced the 2.4ghz 6channel receiver system from the mount and replaced it with good'old 72mhz PCM system and the problem completely gone away!!

Whats more puzzling is that my 2.4ghz system ON the heli itself was not affected by this, only the 2.4ghz on the Mount did.

still puzzling me 900mhz should no be interfering with 2.4ghz, but no issues in terms of flying and 72mhz was adequate for the mount.

[aramsdell]

R-4-L. If you only have the mount Rx powered on ,not the airframe Rx, and you power on the 900 mhz does it still happen? Should the 2.4 ghz Rx's be the same number of channels?

[R-4-L]

the airfram Rx seemed to have no effect at all on this interference nor it was affected by it . it was all localised with the mount, and I am guessing this is due to the type of 2.4Ghz Rx i have on the airframe being alittle more robust than the 6channel one on the mount.

[Steve M.]

is anyone aware of the frequencies allowed in France for downlinks?