nitroman88

My Feedback: (5)

subject is the question

thanks

Jim Schwagle

My Feedback: (1)

Unless you have a "module", a small box that is replaced to change the channel, changing a crystal in a transmitter is illegal.

Steve Guinn

You can change modules in transmitters. It is illegal to change the crystal without sending it in for retuning.

amcross

My Feedback: (2)

All of the above assuming you are in the US.

Futaba's site has a nice area that talks in depth about changing frequencies within a band, changing modules, changing crystals, etc. You might find it helpful. it is on www.futabarc.com in the FAQ area

nitroman88

My Feedback: (5)

Then why are they sold??????? IS changing TXs only illegal for FM????????? My radio is a lynx 3d it has a module, I cannot find the modules that have the crystal in them and are tuned. I understand that I could buy the spectrum module.

amcross

My Feedback: (2)

Nitro,
They are sold to replace crystals, and also because in other parts of the world you CAN change transmitter crystals. NO you are not allowed to change tx crystals on ANY AM/FM/PPM/AnyOtherType in the US, except when using a modular system.

You can definitely purchase modules for your hitec radio. Please look in your manual, determine the model of module needed, and purchase that particular module on the needed channel.

stratcat98

The modules allow you to change mhz. like 72- 27- 75mhz, I'm assuming your running a gas car or truck. Speeding is illegal but at roar events it is common practise to change your crystals for the next race. You actually have to give your alternate crystal #'s when you sign up. Your lynx 3d has the ability to change between 75-27 mhz by changing the module, you may also replace the module with novaks or hitecs synthesized module that allows you to dial a frequency.

nitroman88

My Feedback: (5)

[QUOTE]Originally posted by amcross
[B]Nitro,
They are sold to replace crystals, and also because in other parts of the world you CAN change transmitter crystals. NO you are not allowed to change tx crystals on ANY AM/FM/PPM/AnyOtherType in the US, except when using a modular system.

You can definitely purchase modules for your hitec radio. Please look in your manual, determine the model of module needed, and purchase that particular module on the needed channel.

I have seen people change them because someone else had thier channel. Why is it illegal????? and other then it being illegal will it effect performance too a noticable degree. I understand that you can buy the modules but I cant seem to find any place to get em.

David Cutler

The FCC (the body in the USA that handles communication of all sorts) says it's illegal to change the crystal in your transmitter.

This only applies to the USA.

It's because we share the 72 bands with somebody else (who are, in fact the primary users of the 72 Meg bands) and our channels fit between theirs. Just changing the crystal in your transmitter will not make the new frequency it transmits stable enough not to bleed into the other frequencies between ours.

Actually, I'm not sure I believe it's that critical, but the legislators do, and they are a LOT more important than we are!

I believe the primary users of the72 Meg bands are earth movers etc, which are fairly critical users if something goes wrong!

-David C.

amcross

My Feedback: (2)

I have seen people change them because someone else had thier channel. Why is it illegal????? and other then it being illegal will it effect performance too a noticable degree. I understand that you can buy the modules but I cant seem to find any place to get em.


It is illegal becuase modelers are just "spare" or "hobby" "users" who are sharing small frequencies wedged in between high dollar high business PAYING frequency users -- things like construction cranes, PACE MAKERS, etc. AMA does NOT pay for our frequencies, but the FCC is QUITE concerned that we not bleed onto these primary users.

It is not so big a concern for car modelers as their radios tend to transmit a much shorter distance than aircraft radio systems, but it is still an issue.

Here's just one of thousands of places to buy your module:

http://www2.towerhobbies.com/cgi-bin...?&I=LXELU8&P=7

nitroman88

My Feedback: (5)

75mhz operates on 61-90. Im on channel 74 right now. you are saying that I cant change too channel 75 legally?????

Lynx

As soon as you remove the crystal from the TX you're technically breaking the law. Practically speaking this is absurd but it's good practice to have a crystal tuned for the transmitter it's in. Thing is I doubt even someone certified to do crystal changes bothers retuning for a single channel change. It's more about liable than anything else. If you do it and something bad happens it's your fault. If you don't and something happens it's not your fault. Your choice weather you want to take the chance.

nitroman88

My Feedback: (5)

I am confused. Why does it matter who does it???????????????? I would be doing the exact same thing as they are. 61-90 is for RC use why would it be illegal????????

Steve Lewin

When you say you would be doing exactly the same things do you really mean you have access to a spectrum analyser and will be checking the RF output to make sure that it isn't accidently bleeding into any of the commercial frequencies which are interleaved in between the legal R/C frequencies ? Honest ?

BTW it's illegal because the FCC says so. That's the way laws work, someone in power says don't do it and most people don't.

Steve

amcross

My Feedback: (2)

>

61-90 are for rc use. HOWEVER, there are primary band users BETWEEN 61 and 62, between 62 and 63, etc, who are PAYING FCC CUSTOMERS. We are FREEBIES AS A COURTESY OF THE FCC. Cause a good accident for primary band users and find out how much longer r/c gets to keep 61-90.....

nitroman88

My Feedback: (5)

So your saying if the module isnt "tuned" then it may "bleed". All intresting by why should I have to pay 30.00 just to change one channel. the link to tower shows the 72mhz module, my recievers are on 75 so I dont think that would work out too well. really All I wanted was a extra rec and tx set of crystals because I race.

hebertjj

Nitro,

What part of "because it's illegal" don't you understand? Write the FCC and tell THEM about "all I wanted ... because I race".

That being said, I understand that Multiplex (now owned by Hitec ) has an FCC waiver to allow Tx xtal swapping.

amcross

My Feedback: (2)

This is why modules are available, so you CAN legally, safely change channel.

"All intresting by why should I have to pay 30.00 just to change one channel. "

Obviously, you don't care what the right answer is, so why bother continuing the discussion? If you dont want to buy extra modules, buy the synth module so you can change channels.

Steve Guinn

Why don't you hold your breath and stomp your feet.
Then maybe the FCC will let you change crystals. :drowning:


(Then again, maybe you'll just pass out and go away)

Jim Schwagle

My Feedback: (1)

Just thought I would mention...

Swapping tx crystals on 27MHz in the US is ok, 72 & 75 is illegal.

strato911

Nitroman - when the cops pull you over and write you a ticket for speeding, do you ask why it is illegal? Do you try to get out of it by saying you just wanted to get home sooner?

Plenty of people have told you it is illegal... Accept it.

Here's a 75Mhz module for your Lynx 3D which will let you legally change to any channel on the 75Mhz band:


(click on the picture)

nitroman88

My Feedback: (5)

ok thanks

theox

http://www.rcgroups.com/forums/print...828&perpage=61

Ladyflyer

My Feedback: (2)

Sealed ,potted RF decks would be a step in the right direction. Of course they would have to outlaw all the non sealed RF decks and force everyone to buy new gear. The manufacturers wouldn't mind one bit

SAVAGEJIM

It may be illegal, but in my opinion (I express that it is only my opinion) that the law is retarded when crystals can be changed safely.

We as American citizens have the right, and even the obligation to voice out our displeasure against frivilous and wrong laws. Yes, we should express our displeasure against such laws and not just simply accept them as unchangeble. We can lobby (we should instead of just accept them) and have such laws cluttering our books repealed.

Look at Martin Luther King Jr. He focused on eliminating discriminatory and degrading laws in a great move to bring about more equality for people of all colors, religions,cultures, etc. They just did not lie down and accept useless and wrong laws. They stood up, started a movement, and had many of those "Jim Crow" laws repealed and eliminated.

My point is we should not just accept a frivilous law just because it is a law. We should take action by expressing our opinion and interest. We can even write our congressmen (senatores and representatives, state and federal) to vote to repeal such laws. We can even vote in appropriate people who will remove such laws or make it their effort to remove such laws when in office.

I know repealing the law prohibiting changing frequencies in 75Mhz is making a mountain out of a molehill, but the way I see it, it is removing a useless law that clutters the law books so law enforcers can focus on more important issues (primarily to protect and serve instead wasting time and effort to write citations for breaking a useless law). Besides, how many police departments can spare a policeman to patrol RC parks for illegal crystal changes? They have way more important issues to handle.