Johnno,
Regarding the post mentioning antennas and regulations, where U.S. is concerned he is correct. Once licensed by the FCC no changes to the system that deviates from the submitted design are permitted by the general public. Only those possessing a HAM radio license are legally permitted to make alterations with any alterations remaining in compliance with a bunch of other regulations that govern technician and higher level activities. Pretty much anything that alters RF power and RF radiation range is tightly controlled.
Our FCC regs are commonly violated by people involved in RC activity, with a large percentage of the violators involved with multirotor stuff looking for longer range through more powerful transmitters and antennas. Lacking a HAM radio license, anything they use is supposed to have been granted FCC certification, something most don’t have.
This is an area where for most ignorance is bliss as our FCC laws are not well enforced so people get away with it. Unless people in an area start complaining about interference suddenly showing up at their TV’s, radios, or phones the stuff goes unnoticed. Events occurring that induce a court case, personal injury, property damage, or a significant airspace violation for example, we can be assured the plaintiff’s legal investigative team would look for any violation that would bolster their evidence against the defendant. Should they find non compliant radio frequency transmission components a win would almost automatically go to the plaintiff as the aircraft should not have been in operation. The flight would have been illegal from the moment the system was powered on.
The rules regulating what we do are extremely complex and few understand all of them. I know I don’t. Something that adds to issues of compliance is that we can buy stuff from overseas that is totally non compliant, from manufacturers that don’t care about our regulations. We can buy 500-1000mW or higher video transmitters for just about any frequency band, which is blatantly illegal for anyone without a HAM license. Overseas manufacturers only care about selling their products and don’t care at all if the end use is legal, or not. They got what they wanted; money, and only rarely will they be prosecuted for it. I’m aware of only two that have, with one of them selling frequency jammers over here. Hobbyking got nailed for non compliant frequency transmission equipment. Technically, their products are supposed to be certified before they are imported to the U.S. but they usually are not. But who’s checking?
For most it’s not a big deal as they don’t put themselves in situations where problems might occur. Those participating in higher risk activities that would generate a lot of visibility should something happen might consider assuring their radio equipment remained in its certified state. Those operating professionally are in an even more tenuous position as their professional certification declares they are cognizant of all the regulations involving their activities. It’s all good...until we get caught.
The EMI and cooling stuff you are working on should not fall within the RF regulatory environment as neither activity propagates RF transmission. The GPS elevation/cooling tower does not alter signal strength.