The following is information relevant to the ongoing discussion as to whether and how I can build my own 2.4 Ghz radio system and use it to fly remote controlled aircraft.
This post ONLY regards AMA rules. I will address FCC rules in another post at a later date.
Reference the AMA Membership Manual 2010 as found at,
Identification of narrowband transmitters 3. AM transmitters that were verified by test to be narrowband prior to March 1998 are considered to be narrowband. A goldcolor sticker, marked ?R/CMA AMA - RF CHECK? was formerly used to identify these tested transmitters. However, it is no longer required to display the R/CMA AMA Gold Sticker on these transmitters.
This clearly shows that the Gold Sticker only applied to 50, 72, and 75 Mhz bands, as those are the only ones which have channel numbers. 2.4 Ghz uses spread spectrum and therefore does not use channel numbers.
Further, it clearly sates that this in no longer required.
So that takes care of the Gold Sticker argument.
Page 10 - Frequencies for Radio Control 1.4. RC is permitted in the 2.4 GHz industrial, scientific, and medical (ISM) band using spread spectrum technology from 2.4 GHz to 2.485 GHz.
Self explanatory.
Page 11 - FCC Legal Requirements and Safety Recommendations 3.0. RC users shall comply with FCC regulations. RC users of the Low Power 2.4 GHz band are required to comply with CFR Part 15.
The AMA will not assume responsibility for enforcement of the CFR.
However, if the violation impacts safety, corrective action may be taken.
The last only applies if there is a safety issue. Even if there is an FCC violation, the AMA clearly states they don't enforce FCC rules, and clearly states they only care if there is a safety issue.
Since my radio will comply with necessary FCC rules there is nothing to worry about from the AMA. Besides, a safety issue could apply to ANY radio system.
Nowhere have I found any statement saying that any radio used must be certified by the AMA. The closest I've found to any kind of restriction is the following,
Page 11 - FCC Legal Requirements and Safety Recommendations 3.1. AMA RC event officials shall enforce FCC Amateur Radio Operator licensing requirements. Use of legal Amateur Radio Service frequencies other than those listed in paragraph 2.1.4. and 2.1.5. is permitted at sanctioned events at the discretion of the event officials.
This means that if you operate a radio on an amateur frequency the official is required to make sure you have any necessary amateur radio lcenses. The 2.4 Ghz band does not require a license, especially when operated under part 15 rules.
However, since 2.4Ghz use is outlined in 2.1.6 and not 2.1.4 or
2.1.5 as stated, it appears to be at the discrection of the event officials. In fact, this would appear to apply to ANY 2.4Ghz radio, whether it's my home made radio, or even a Spektrum, JR, or Futaba bought at your LHS!Nowhere have I found any statement regarding home built radios.
As an intersting aside, I found a rule regarding channel frequency radios tuned with a crystal.
Page 9 - Radio Control Operation Operation of RC Flying Sites: Any user modification of a transmitter that might affect the transmitted signal is prohibited by law and safety concerns. This includes user replacement of frequency determining plug-in crystals and use of plug-in frequency modules from another manufacturer. Transmitter crystal replacement, with or without a change in frequency, requires transmitter emission realignment by the manufacturer.
So if you have one of these radios and change the crystal without sending it to the manufacturer to have the system checked, you are in violation of AMA rules if you use it at the flying field. This one takes me by surprise. But it's just a curiosity and not relevant to the current discussion.
Brian