I've just added this page of tips on choosing radio frequencies to the manual. Corrections/suggestions?
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Some tips on picking wireless frequencies
Wireless can be something of a black art, and there are a dizzying array of standards and choices. Here are some simple guidelines to help you pick wisely:
RC and amateur UAV gear usually operates in these frequency ranges:
- 72 MHz (older analog RC gear in the US)
- 35 MHz (older analog RC gear in Europe)
- 433 MHz (RC and telemetry, in Europe)
- 900-915 MHz (video and telemetry, in the US)
- 1.3 GHz (video)
- 2.4 GHz (digital RC gear, video and telemetry)
- 5.8 GHz (video)
It is a bad idea to have transmitters and receivers in the same frequency range, so you'll want to choose your equipment to avoid this. Even if they use different frequencies, try to keep transmitters (telemetry, video) and receivers (RC, GPS) as far apart as possible. The only time you should consider having two radios onboard that share the same frequency is if they are digital spread-spectrum radios, such as those in the 2.4 GHz range.
In general, the lower the frequency the longer the range because it can go around obstructions better, so 900 MHz video tends to have longer range than 2.4 GHz video. But digital transmission technology can more than compensate for that, so it's not a hard-and-fast rule. For instance, a high-end spread-spectrum 2.4 GHz wireless video setup can outperform a lower-end 900 MHz one.
Some frequency ranges are more crowded than others. For instance, indoors and in urban environments 2.4 GHz has to compete with everything from WiFi to Bluetooth to cordless phones. 900 MHz just competes with some cordless phones.
1.3 GHz is quite close to the frequencies the GPS satellites transmit at, and it can degrade your GPS performance. If you are using a 1.3 GHz transmitter, keep it as far from your GPS module as possible.
Here are some sample recommended configurations:
| RC | Telemetry | Video | |
| Configuration 1 (US) | 2.4 GHz | 915 MHz | 5.8 GHz |
| Configuration 2 (Europe) | 2.4 GHz | 433 MHz | 5.8 GHz |
Configuration 3 (US) Configuration 4 (Europe) |
1.3 GHz 1.3 GHz |
Comments
That good
I just came upon these on eBay and would like to ask if anyone have any experience with them?
PCS Wireless RF Transceiver Module 433Mhz CC1101 RF1100
http://www.ebay.com/itm/260915777476?_trksid=p5197.c0.m619
Don't forget running LRS for your RC TX/RX in the US (ham license required). I always think of getting a clean long range video signal as the biggest obstacle so this is my preferred setup.
RC: 433 MHz
Telemetry: 915MHz
Video: 1.2/2.4/5.8 GHz :)
I've expanded my comment into a Blog Post here: http://fpvuk.blogspot.co.uk/2012/12/uk-telemetry-fpv-frequencies.html
All the best
Simon
Stephen: Thanks for the link. Your blog is fascinating!
What about use the 2.4 wifi built-in gopro 3 for video (not for FPV, just for see what pictures are you taking) and a different frecuency for the RC?
The 2.4 wifi of our phones and tablets is so nice for don't use it!
Hi Chris,
In the UK we're limited to 1mW for telemetry on 433MHz. 10mW on 434MHz. Are there systems available which work at those power levels/ frequencies?
For Radio Control we have 35MHz and 2.4GHz as you mentioned but we also have 459MHz up to 100mW available to us and many of us use OpenLRS and EzUHF with special "UK firmware" which changes the frequency from 433MHz to 459MHz at 100mW. OpenLRS using this special firmware has been flown to over 13km which is more than sufficient for most applications (especially considering our Air Law requires that Line Of Sight is maintained at all times).
Source: http://stakeholders.ofcom.org.uk/binaries/spectrum/spectrum-policy-... Page 59
All the best
Simon
You may want to mention that pilots in extremely warm and humid air may suffer reduced range with 5.8 GHz.
The effect is noticeable enough that some people claim a rule-of-thumb that every doubling of frequency will cut range in half. Obviously completely untrue, or course, but it's out there.
I fly 5.8 GHz because the equipment is smaller and lighter (maybe add antenna size to the table?) and there are more legal channels available for it in the U.S. Of course, the air is pretty dry where I am...
Chris this looks good. I also like where you put it on the wiki. thanks! I Was thinking you could add in the 433 MHz stuff for in the US and mention you must have an Amateur Radio license but that would complicate the straightforwardness (<- is that even a word?) of the page. Now to find my Debit Card. :)
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