what is required to change crystal - from FCC

From time to time I have seen that some magical annoiting must proceed
legality to change a crystal. Turns out not only can you change a crystal,
but if you want to change every componet in your R/C transmitter - Your
legal,
The following is from the FCC website as to what services are exempted from
requiring a commercial license to maintain a transmitter:
You do NOT need a commercial radio operator license to operate, repair, or
maintain any of the following types of stations:
Two-way land mobile radio equipment, such as that used by police and fire
departments, taxicabs and truckers, businesses and industries, ambulances
and rescue squads, local, state, and federal government agencies.
******************************************
Personal radio equipment used in the Citizens Band, Radio Control, and
General Mobile radio services.
***********Emphisis added ********************
Auxiliary broadcast stations, such as remote pickup stations.
Domestic public fixed and mobile radio systems, such as mobile telephone
systems, cellular systems, rural radio systems, point-to-point microwave
systems, multipoint distribution systems, etc.
Stations that operate in the Cable Television Relay Service.
Satellite stations, both uplink and downlink of all types.
Reply to
W4JLE
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That's true. The only requirement is that you are competent to do the work and have access to the necessary test equipment.
Reply to
Will Hicks
Smart comments aside, thank you for the clarification. Dr.1 Driver "There's a Hun in the sun!"
Reply to
Dr1Driver
And WHO makes that call?
I took a test that was given by the FCC in 1969 to prove my competence, but now that license is not required for personal radio stuff. It is still required for avionics though.
Dan Thompson (AMA 32873, EAA 60974, WB4GUK, GROL) remove POST in address for email
Reply to
Dan Thompson
There is no requirement of competency or any other requirement. I doubt that anyone without a smattering of knowledge is going to tear into their new 10 ch. JR just for grins. So I guess we can say it is self regulating.
The chains of regulations are cast off, let's change them crystals!
Reply to
W4JLE
I wouldn't bet on that! Having the money to afford the radio does not guarantee the smarts to handle it properly! To include cracking it open to see how it works!
Reply to
C.O.Jones
This is all true, however, it only applies to the need for a commercial radio operator license. You still need to verify that the transmitter is operating within it's design specifications.
Spectrum analyzers are getting cheaper, but you aren't going to be able to use it at the field after swapping a crystal.
For that matter, you can get a Hitec Eclipse 7 with Spectra for $200. Do it right or don't do it at all.
--- Rich
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Reply to
Rich Lockyer
| The 21st century version of "Dial-a-Crash. If you don't believe me, | tell me how to find out what channel the radio was left on last.
You pull the module out (if the things to adjust are on the inside, I'm not sure) and see what channel it's dialed to?
| This radio system comes with a whole set of operational problems I | have never heard resolved. Like how do you tell everyone else you | are on channel 12 when you don't have a flag for it, and yesterday | you were on channel 53.
You make one flag for each channel you might use? (Your `you don't have a flag for it' restriction is pretty arbitrary. People with non-synthesized radios often don't have a flag either, though they probably should.)
Some people have a blank flag, and use a dry erase marker on it.
| The biggie I got from a conversation with another is remembering what | channel YOU put the radio on last week. Hence, the D-A-C remark.
Of course, you also need to remember what model your radio is on. Exactly the same sort of problem, except that mistakes usually only crash your plane, not other people's planes.
These aren't really problems with the radio -- they're easily rectified by some dilligence on the part of the pilot.
The Tracker II has a scanner in it that won't transmit on a channel already being used. That's a pretty elegant solution to this problem, though it won't stop somebody without a Tracker from turning on when your transmitter is already on. But if everybody had one ...
The biggest problem I see with a synthesizer is the *possiblity* of causing a crash. If you have a non-synthesized radio on a given frequency, and you're sharing the frequency with somebody else, and they're flying and crash, they could accuse you of causing their crash by turning on -- and there's not really any way of disproving that, even though you know you didn't even touch your radio. With a synthesized radio, *anybody* could make the same accusation against you.
I guess that could be fixed by having a radio with an accurate internal clock that logs when it's turned on and off, and keeps track of what channel it's on each time ... but I don't think anybody does that. Or just leave your radio in the impound area, if there is one.
Reply to
Doug McLaren
Hey, he said he built them, he never gave any indication that they actually worked.. after he built them >:-) Probably just used 'em as ornaments.
Reg
Reply to
reg
If you have a Hitec, DOES NOT MAKE ANY DIFFERENCE - THEY WILL NOT SELL TX CRYSTALS ! ! ! ! !
David
Reply to
David AMA40795 / KC5UH
The presumption of intelligence is a dangerous thing.
Presume abject stupidity and then enjoy the pleasant surprises when they occur.
Reply to
Pat Patterson
Standard amateur radio practice is all that's required. A simple band pass filter solves the problem of harmonics.
I suspect many Hams have never seen a spectrum analyzer, let alone used one.
It is only in recent years the prices have come with in reach of the average guy.
Most of us tuned to the harmonics with a receiver and confirmed they were sufficiently suppressed.
Reply to
W4JLE
International Crystal at
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will supply any crystal needs you may encounter.
Reply to
W4JLE
You noticed the same problems I did! That need for structure is exactly what makes that type of radio system dangerous in the hands of Frankie Fightpack. I prefered the old system that cost around $1300 because USUALLY folks spending that kind of $ on a transmitter are careful.
Rich, your points are valid but ignore the masses which is where our 'problems' will come from with this type of system. That was my entire point, nothing else was intended or implied which echos your "Do it right or don't do it at all." statement.
W4jl the difference is the D-A-C system can be changed from flight to flight and has NO need for TX crystals. I think the Tracker II does it for BOTH TX and RX. In short, our frequency flag system needs some help here.
Reply to
Six_O'Clock_High
I've gotten crystals from ICM before. Question is - what load capacitance (CL) does one specify for Hitec usage??
Besides, at $20 for crystals from ICM, it is cheaper for me to send the 3 transmitters I want to change to Hitec - $15 each plus shipping AND I don't have to screw around with ordering from ICM and doing the retuning!!!!
David
Reply to
David AMA40795 / KC5UH
The load capacitance of a crystal needs to be specified as parallel o
series as well as the value in pico Farads. There is also the actua frequency the crystal oscillator is required to work at may not be th transmitted frequency. Some FM transmitters use 1/2 or 1/3 of th output frequency in order to more easily generate the required level o modulation and then multiply it up. You may be able to get thi information from the radio manufacturer.
I live in the United Kingdom and we've always been able to us pluggable crystals so getting them is as easy as going down to the LH and stating frequency and radio make.
It sounds like some paranoia as far as the FCC is concerned or som misinterpretation of the rules if, as stated above, it is legal in th US to change crystals.
Its quite easy to replace the crystal with a socket then plug them in just don't use one that's been soldered to it won't make good contac in a socket.
I wonder how many flyers in the US have done this and not told anyone.
Pluggable crystals can't be a problem because we in the UK had some o the most rabid radio regulatory rules such that CB was illegal unti the late 70's and when it was allowed, they put it on FM and o frequencies that no one else used.
my 2pence worth,
Andy. G8MQ
- AndyOn
And
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Reply to
AndyOne
What I suspect it is (on the part of the FCC anyway) is antiquated rules. Rules that had a valid purpose back when radio technology wasn't as technical as it is today. And changing a crystal required a complete re-alignment of the RF deck. But like most government regulations, the FCC has been unable to keep up with the times.
Chuck
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Reply to
C.O.Jones
It seems to me they have kept up. They have said you can maintain your radio with no special license requirements. It is perfectly legal for you to change a crystal.
Reply to
W4JLE
But when was this enacted? Or has it always been the case and we've simply been shammed by our own R/C industry? :)
Reply to
C.O.Jones
1980 under Reagan and yes you have! Dan Thompson (AMA 32873, EAA 60974, WB4GUK, GROL) remove POST in address for email
Reply to
Dan Thompson

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