I understand this may be a stupid question, but if I buy a 75mhz transmitter + receiver crystal set, it will work fine in BOTH airplane and car transmitters AND receiver, right?

(I use an airplane transmitter with a surface crystal for robotics).

Thanks,

Jason

ya it will. controller + reveiver will controll whatever you want

72 mhz and 75 mhz are NOT interchangable. you can not buy a crystal for one and use it in the other. besides, swapping your tx crystal is illegal anyway, at least for air frequencies.

you are using a 72 mhz radio on 75 mhz for robotics now??

???

I am NOT using 75 mhz for air use or 72 mhz for surface use.

All I wanted to know was, if I bought a tx + rx crystal set @ 75mhz, I could use it in my car transmitter, and in my airplane one for robotics (SURFACE) use.

I'm quite aware of the FCC regulations.

I don't know what you're smoking?
It's against FCC rules to use 75mhz for Airplanes, and 72mhz for Surface,,, It not Against any rule to swap crystals beween Transmiters and recievers. As long as you are Brodcasting on the right #mhz for the application you not in any vilolation

And By the way,
I've used Futaba 72mhz Moduales and Rx in my Hitec Linx 3D (75mhz TX) and car,Against The Rules,, it works fine. I wouldn't test the oposite it in any of my airplanes,,, but yes it will work for a Robot or other surace use. If you want it fine tuned send the radio in and they will make sure it works perfect

A buddy did that with his 6cnl Airtronics Tx because he wanted to control a boat with a bunch of features with it,,Futaba even tells how to have it done on their web site

party on Garth

umm, sorry, guess you didn't read your owners manual. it IS against fcc rules to change the frequency your transmitter is on, if you have a crystal based radio. if you have a module based radio you can swap modules, but pulling out a crystal and putting in a different one is is illegal.

here is a link to the fcc part95 which governs this, section 222 in particular.
http://frwebgate.access.gpo.gov/cgi-...2000&TYPE=TEXT

and also section 645 which defines what a module is and isn't
http://frwebgate.access.gpo.gov/cgi-...2000&TYPE=TEXT


and finally, 653 saying that this has to all be stated in your manual
http://frwebgate.access.gpo.gov/cgi-...2000&TYPE=TEXT


yeah, people ignore these sometimes, but it opens you up legally to a whole bunch of problems. If you swap crystals and cause someone to crash, you might now be liable for any damages that happened. same with using 72 mhz to control a boat. if someone puts up a plane on the same frequency, guess what, you just bought yourself a plane (or millions of dollars in a lawsuit if the plane happens to kill someone)

also, do you have a link to the futaba site where it tells about using airtronics equipment? I highly doubt futaba is recommending doing anything like this. Even using a module from a different manufacturer is not legal, since it hasn't be certified for that radio. (common example is people using hitec spectra modules in a 9c. they work, sometimes, but it still isn't legal)

wow, you went to all that trouble to dig up regulations that will never be inforced??
And I know all about liability,,,I've been in the ama on and off for 30years

And lastly no one is saying using 72mhz in a land application,,I was just curious so I tested it

If swapping crystals is illegal then why do all the manufatures sell replacement crystals? or extra ones so you CAN change the Tx frequency? I guess the are just law breakers

I did mean to say that futaba explains how to change airtronics radios, they tell how to change their 72 to 75,,,sorry if that was confusing
http://www.futaba-rc.com/faq/faq-6xsuper-q54.html

Good luck DestroyerX

nope, just stole it from rc groups! [8D] (I didn't post that initially, i've had posts deleted for linking to info on rcgroups...)
http://www.rcgroups.com/forums/showthread.php?t=94580


yup, changing freqs (and bands for some radios) is legal if performed by the 'authorized service center'... I've always wondered if they actually retune anything if you send it in for a freq change, or just drop in a new one and charge you $20.

I was never switching crystals. When I bought my airplane transmitter (Hitec Laser 6), I ordered it with a 75mhz crystal from *********.org. If anything was done to modify to 75mhz, they would have to have done it before selling it to me to be legal according to the FCC regulations you showed me. I have never used a 72mhz crystal in that radio.

My overall question with this topic was just; if I buy a 75mhz crystal set, will it work in both an airplane and car transmitters, and airplane and car receivers.

"Had enough" answered my question a few posts back.

I have another question though. I plan on using the crystals in a hitec transmitter + receiver, and a perfex transmitter + receiver. If I bought the futaba crystal set on:

http://www2.towerhobbies.com/cgi-bin...I=LXH281**&P=0

would those crystals only work in futaba radios?

Or would the way to do it be just to buy a transmitter crystal made by the company of the transmitter, and a receiver crystal made by the company of the receiver at the same frequency as the transmitter one?

Thanks,

Jason

You know I was told before that you have to use futaba crystals in futaba receiver and hitec in hitec, but I know from my testing the futaba crystals work in hitec and vis versa,
I've only done this in my Cars and would not ever think of taking the chance with my airplanes

I have also tested the hitec 75mhz spectrum synthesized module in my 7uaf and 8uaf Tx,,also both work fine
Also I have used Futaba and Hitec receivers sold with 72 Mhz crystals with 75 mhz crystals in my cars and they too work fine

But again these are all Module type TXs so I guess I've never been in violation of FCC rules
I have been in violation when switch TX crystals in my cheap futaba T2PC AM TX,,,I wonder why they have the crystal slot on the outside of the TX and they sell crystal sets if it's a illegal to do so? Please no one call the cops on me or all the guys at the track,,, this goes on all the time,,,I guess we could blame Futaba for entrapment

I can't speak to the "Perfex" system being compatible with the futaba crystals, if the Perfex is Futaba compatible then I'd guess yes,,,Who makes the Perfex?.

Kyosho makes Perfex radios.

I plan on buying the futaba 2pl with receiver. Do you think the tx and rx crystals from it would cause me problems if I used them in my hitec laser 6 tx and rx?

If so, I'll just buy a crystal set made by hitec for my airplane tx and rx.

Thanks,

Jason

This is getting complicated.. 72mhz Futaba RX's are hi/low banded. That might affect this? If I were you I would re-ask this question in the airplane radio area. Not to diss the car guys but the air guys know a lot about radios.

Only the Futaba 72mhz recievers come tuned Hi or Low band they recomend When you change frequency you keep in either Hi or low otherwise send in the Reciver to be fine tuned for maximum range. The others RXs including the 75mhz RXs are center band tuned and will take any crystal, They now it's for ground use and radio range isn't as critical and in an airplane

Example, If you have a 72mhz on channel 20 (low band) you don't want to change it to channel 50 (hi band),, You'd want to chose a channel 11-35,,,high band channels are 36-60

But as far as I know Futaba is the only one that recomends this,,72mhz Hitec recievers come in only one form and will take any crystal in the 11-60 range

Been an Airplane guy for 30 Years

Thanks for the info.

I had another question that's more car related.

I currently own a Kyosho mini-z running at 27mhz.

If I buy the Futaba 2pl:

http://www2.towerhobbies.com/cgi-bin...=LXENN3**&P=ML

Could I buy a transmitter crystal of the same frequency of the receiver crystal in the mini-z and expect the Futaba 2pl to work with the mini-z?

Thanks again,

Jason