newbieT,
Changing Tx crystals is against FCC regulations in the US (not so in other countries), changing Rx crystals is fine, and the only place that Futaba has "Low" and "High" bands.

FH did have an attitude about always being right, and probably painted a big target on his back as a result. He was msot often right, but presented an "air" with his replies quite often.

5_Spot,
JR never sold crystals (or equipment) on channels 11 through 14 in their single conversion line, which is where all the controversy is coming from. It's nothing new and doesn't affect anyone.
Dennis-

Nevermind,


I've got better things to do.

http://www.rcgroups.com/forums/forumdisplay.php?f=135

The first two "sticky" posts are about crystal issues...

dano13

Didn't get all the facts as it was just sent to me so i thought i would pass it on.

I don't know if I could find that thread as it was originally about r/c something or another, and then branched into sympathetic harmonics & gearboxs somehow. Anyway, Huber went way, way, really way out on a limb with a long thing about the subject from what I remember. I had to respond to that one as I used to teach the subject a little. I do remember thinking that he had a real attitude about himself when he was expounding upon his knowledge of the subject. He was booted right after that and I never took the time to write my final reply to him about it. It could probably be found with a search of sympathetic resonance, gearbox, ground resonance, critical tailboom dynamic modes, or similar key words. He was smug about what he thought he knew and I just didn't have the patience to try and correct him. With his attitude, he wasn't worth the time or trouble.

I just remembered something: a search for "pylon whirl" may get it.

For those who change out transmitter crystals, just remember that if you are involved with an incedent necessitating insurance coverage, if the AMA knows you changed transmitter crystal, you will not be covered with insurance. That is why it is highly recommended that you do not change transmitter crystals in the USA. Other countries don't have the same problems we have here as they do not have all the other users sandwiched in between the frequencys in use like we do here. There is a rare chance that you could be the cause of a fatality by causing unintentional off frequency operation.

Exactically!

You can change chrystals in transmitters if they are in a selfcontained module. Some Hitec's and older Futaba's had this feature. But the modules were tuned at the factory and exempt from this rule. This is my understanding,Could be wrong. I do know that changing the transmitters chrystals alone is illegal as other posters have mentioned.

Mark Shuman

Crap... I have a Futaba reciever on Channel 26 that I'd like to put on 55. Guess I'm SOL... Looks like I'll get those RX and TX batteries after all....

I know people do change TX crystals, but on several occasions I've noted that the TX did end up causing interference on other channels. Range check was ok of course but there is no way to check adjacent channel stuff easily.

As the holder of a Commercial FCC Radio License I can promise you it IS illegal to tamper with a transmitter in any manner that might change the frequency or type of modulation emitted in a manner other than that specified by the mfg. The pop-in modules that Futaba uses and Kraft used to use as well as the synthesizers are all legal as they are pre-certified as compliant to regulations. I tune and align radios for an airline every day and believe me, big brother is watching me. Even with my licenses, it is hard for me to talk mfg out of schematics for my own radios. By the way, it SHOULD be legal for a HAM operator to change his crystals on sets within assigned channels, assuming he has the equipment to verify proper operation. Go ahead and swap crystals if you wish to be guilty of a Federal Crime. I won't risk my license on it, sending it out is too cheap to risk doing it wrong.