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1.3 GHZ 2.4 GHZ Harmonics

jaberman

Junior Member
#1
I am new to professional rc and I was watching a flitetest video when one of the guys mentioned harmonics in channels and how it could affect your flight. I was thinking about getting a 9000 FPV system but if its in harmony with my 2.4 GHZ transmitter and receiver then I will get something else.
 

vk2dxn

Senior Member
#4
In Australia you need to be a licensed ham (standard or advanced) to operate on all the fpv frequencies excluding 900mhz because that band is not available in Aus
 

Tritium

Amateur Extra Class K5TWM
#5
So how do you get a license and does 5.8 have harmonics with 2.4?
5.8 video works fine with 2.4 RC Transmitter.

If I knew which city you are near in Oregon I could look up where the test is given near you. It cost $15 in most cases. You can find ample study materials online or go to your public library / bookstore and get the Amateur Radio Technician Exam Prep Book by Gordon West. The test requires a bit of study but some 6 year olds have passed the test so it is not too hard.

Thurmond
 

Tritium

Amateur Extra Class K5TWM
#7
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Craftydan

Hostage Taker of Quads
Moderator
Mentor
#9
Short answer: You'll need an amateur license in the United States to transmit on any amateur band.

The pretty-much-useless exception to ths are part-15 compliant intentional radiators (transmitter). Any FPV rig will fail the "part 15" compliance.

Best answer I've seen so far for this (even digs out the data from the reg):

http://www.rc-cam.com/forum/index.p...cense-to-operate-on-58ghz-at-4w-eirp/?p=25068

So what does this all mean? Don't try to use the part-15 license free transmission rules, get a HAM license, and use their rules.
 
#10
Short answer: You'll need an amateur license in the United States to transmit on any amateur band.

The pretty-much-useless exception to ths are part-15 compliant intentional radiators (transmitter). Any FPV rig will fail the "part 15" compliance.

Best answer I've seen so far for this (even digs out the data from the reg):

http://www.rc-cam.com/forum/index.p...cense-to-operate-on-58ghz-at-4w-eirp/?p=25068

So what does this all mean? Don't try to use the part-15 license free transmission rules, get a HAM license, and use their rules.
10mw or less is unregulated
nice correction of misinformation there! there's alot of that (misinfo) on this site lately.
 
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Tritium

Amateur Extra Class K5TWM
#11
10mW is just about useless also for any "real" FPV experience. (Pardons to those who are legislated to 10mW in which case it is Great since the alternative is no FPV).

Thurmond
 

RoyBro

Senior Member
Mentor
#12
10mW is OK for taking a signal from a base station and transmitting it to a pair of goggles a few feet away. That way you don't have to be tethered to your base station.

RB
 

Craftydan

Hostage Taker of Quads
Moderator
Mentor
#13
10mW is OK for taking a signal from a base station and transmitting it to a pair of goggles a few feet away. That way you don't have to be tethered to your base station.

RB
Very true, but the point is it's unsuitable for a downlink from the model. Anything more in the US for analog video in any band will require a HAM license to be legal.


<RANT>

Niggling point about the thread, however:

Part 15 compliance reg doesn't specify wattage at the transmitter in these bands, it specifies max power in millivolts/m at 3m past the antenna. For an isotropic antenna (theoretical antenna with equal radiation in all direction), you're down to 1/2mw for your analog signal to stay below that -- it will be less if you've got any antenna gain (focusing).

I'm sure someone (maybe not here, but somewhere) has seen a GOV reg that states this magical 10mW level, but I've never seen it and it probably applies only to *DIGITAL* signals. Unless you're flying a AR Parrot, I'd lay BETTER than good odds you're downlink is analog, and the regs are MUCH tighter.

Do not trust the OEMs to interpret FCC reg for you *ESPECIALLY* if they exist outside the US. A "Notice of Operation Without A License" is ALWAYS sent to the operator, never the OEM. Granted, it's almost impossible to get one for FPV flight made away from your residence, but the more people breaking the rules, the more likely the FCC will deal with the problem -- something NONE of us want.

</RANT>


Long story short, get your ham license. Several sections will seem like a waste, but you're going to learn things that help you build a better FPV rig -- better for your use with less interference on others.