Changing Tx Crytals
07-10-2002, 01:02 PM
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Changing Tx Crytals
Can transmitter crystals be changed? If so, what are the steps taken to do so? Must the "new" crystal be relatively close to the old frequency (plus or minus 2 channels)? If changing more than that (say ch15 to ch54) - does the transmitter need to be sent in to "recalibrate"? I would like to know this about Airtronics and JR radios. Thanks so much for helping to learn so much about this hobby!
07-10-2002, 01:09 PM
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Changing Tx Crytals
According to FCC rules, transmitter crystals can only be changed by the manufacturer or a licensed technician. The transmitter is supposed to be re-tuned whenever a different channel crystal is installed.
07-13-2002, 12:46 AM
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Changing Tx Crytals
I have no idea on JR or Airtronics but this is straight from the Futaba. With our 72mhz frequencys ranging from ch11 through ch60. They are broken down into two sections (ch11-35) and (ch36-60) You can change them around yourself within those two areas, do a range check and if your happy go with it, if not,send it in.
* Lets say you have channel 32 and you want 55. Cannot do it because your crossing over. Oh you can but you better send it off with your receiver. Everything i own is on the same frequency. Life is easier this way.
* As far as the FCC goes, I was an Army pilot for 20 years and fooling around with things the last 10. I never even met anyone from the FCC. Never knew anyone who was fined. Hams etc. Absolutely nothing. They are ghosts and probably have better things to do. There interests in us is as important as a 6 month old obituary buried in a 4 week old Sunday paper!
* Lets say you have channel 32 and you want 55. Cannot do it because your crossing over. Oh you can but you better send it off with your receiver. Everything i own is on the same frequency. Life is easier this way.
* As far as the FCC goes, I was an Army pilot for 20 years and fooling around with things the last 10. I never even met anyone from the FCC. Never knew anyone who was fined. Hams etc. Absolutely nothing. They are ghosts and probably have better things to do. There interests in us is as important as a 6 month old obituary buried in a 4 week old Sunday paper!
07-13-2002, 08:26 AM
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Changing Tx Crytals
Unfortunately the information you quoted from Futaba applies only to receivers not transmitters which is what the question is about. The FCC ruling forbidding change applies to all makes (except Multiplex who applied for a waiver).
If you are type of person who thinks it's fine to break rules because you're not very likely to get caught then you can change Tx crystals. It's only illegal not impossible. Oddly enough it's perfectly legal in most countries other than the USA.
Steve
If you are type of person who thinks it's fine to break rules because you're not very likely to get caught then you can change Tx crystals. It's only illegal not impossible. Oddly enough it's perfectly legal in most countries other than the USA.
Steve
07-13-2002, 08:44 AM
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Agreed Steve
Why compromise your plane, or worse yet, someone else's safety and well being? People die doing this hobby! This is not a game and these planes are not toys. It amazes me what people will do and why. Once the plane breaks ground the only link we have to getting it back is one we can't see. Lots of things have to be right to have a successful flight. I say do everything in your power to optimize the things you can control. Put maintenance items at the top of the list and check them to the point of overkill.
Take your time and enjoy what you do. This is supposed to be fun. Unfortunately ego and personality are introduced into the mix and skews the recipe...
Take your time and enjoy what you do. This is supposed to be fun. Unfortunately ego and personality are introduced into the mix and skews the recipe...
07-14-2002, 12:10 AM
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Changing Tx Crytals
If you are type of person who thinks it's fine to break rules because you're not very likely to get caught then you can change Tx crystals. It's only illegal not impossible. Oddly enough it's perfectly legal in most countries other than the USA.
For your information I write rules and I do my best to see they are enforced at our city field but some rules are stupid and beyond our control and make no sense.
* Money does not grow off of a tree for me along with millions of others. I read the rules and make my own decision. I am not going to spend 3 months building a plane at around $1200 to play frequency games unless i know what I am doing.
* I have four solid years in this and no crashes. Not because I am good because compared to local talent, I am a fair R/C pilot, but because i am careful. There are two simple rules i fly by.
1. I build at home, the field is for flying. If you run into field builders, stay as far away as possible.
2. If anything goes wrong that requires a tear down, then pack it up and hang out for a while with the guys, help out or whatever but leave that mess for the house.
Anyways to get back on track, Futaba wrote this stuff not me
* One of you guys just stated people do get hurt and die but mostly from stupidity and radios in proper working order. Pilots losing planes-I got a radio hit. Well those who understand how "hits" work will look alot further than the impound area.
* Radio wattage does not have to be very powerful to travel great distances. You can get hit from a guy flying an r/c plane a hundred miles away if conditions are right.
Whatever the case, go with the MFG's . I'll tell you this , I have never seen a plane completely replaced by and MFG due to radio failure.
For your information I write rules and I do my best to see they are enforced at our city field but some rules are stupid and beyond our control and make no sense.
* Money does not grow off of a tree for me along with millions of others. I read the rules and make my own decision. I am not going to spend 3 months building a plane at around $1200 to play frequency games unless i know what I am doing.
* I have four solid years in this and no crashes. Not because I am good because compared to local talent, I am a fair R/C pilot, but because i am careful. There are two simple rules i fly by.
1. I build at home, the field is for flying. If you run into field builders, stay as far away as possible.
2. If anything goes wrong that requires a tear down, then pack it up and hang out for a while with the guys, help out or whatever but leave that mess for the house.
Anyways to get back on track, Futaba wrote this stuff not me
* One of you guys just stated people do get hurt and die but mostly from stupidity and radios in proper working order. Pilots losing planes-I got a radio hit. Well those who understand how "hits" work will look alot further than the impound area.
* Radio wattage does not have to be very powerful to travel great distances. You can get hit from a guy flying an r/c plane a hundred miles away if conditions are right.
Whatever the case, go with the MFG's . I'll tell you this , I have never seen a plane completely replaced by and MFG due to radio failure.
07-14-2002, 07:54 AM
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Changing Tx Crytals
Let's clear this up Mr. Hardover.
You quoted some information from Futaba about changing *receiver* crystals. Changing *receiver* crystals is perfectly legal. You quoted this information in response to a question about changing *transmitter* crystals which is not legal and which Futaba always make very clear is not legal. You quoted misleading information. It was probably a misunderstanding on your part rather than malicious intent but it was never the less misleading.
You then say
"For your information I write rules and I do my best to see they are enforced at our city field but some rules are stupid and beyond our control and make no sense.
* Money does not grow off of a tree for me along with millions of others. I read the rules and make my own decision."
So you think everyone should obey the rules you make for your city field but that you are entitled to pick and choose which of anyone else's rules you bother to obey. I'd say that makes your attitude fairly clear.
Steve
You quoted some information from Futaba about changing *receiver* crystals. Changing *receiver* crystals is perfectly legal. You quoted this information in response to a question about changing *transmitter* crystals which is not legal and which Futaba always make very clear is not legal. You quoted misleading information. It was probably a misunderstanding on your part rather than malicious intent but it was never the less misleading.
You then say
"For your information I write rules and I do my best to see they are enforced at our city field but some rules are stupid and beyond our control and make no sense.
* Money does not grow off of a tree for me along with millions of others. I read the rules and make my own decision."
So you think everyone should obey the rules you make for your city field but that you are entitled to pick and choose which of anyone else's rules you bother to obey. I'd say that makes your attitude fairly clear.
Steve
07-14-2002, 10:05 AM
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Top Dawg
Let me know if this answers your original question? If so, I would like to see this thread continue in the Radio forum, or just stop it here. Thanks and let me know_bob
07-14-2002, 12:51 PM
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Changing Tx Crytals
To clarify, the Futaba info about changing frequencies in to ranges is for RECEIVERS, not transmitters. I cut/pasted the relevant info below. Note that the info about receiver channels is for FUTABA ONLY, check with the mfg for other brands. The transmitter info applies to all brands (its FCC regulation).
http://www.futaba-rc.com/faq/service-faq.html#q2
For a unit with crystals: We CANNOT recommend changing crystals to a different frequency. Changing the crystal on your transmitter is illegal unless you have the proper license. The FCC has established guidelines for the modeler's safety and for the safety of spectators. For safety and FCC reasons we must request that both TX and RX be sent to the service center to ensure proper crystal change and retuning to the new frequency. Crystal based radios cannot be converted to another band without parts replacement, and may not be able to be converted at all. Certain radios can be converted, for example, from 72 to 75MHz. Please contact the service center for any other conversions.
The applicable Federal Regulation is as follows:
TITLE 47--TELECOMMUNICATION COMMISSION (CONTINUED)
PART 95--PERSONAL RADIO SERVICES
Subpart E--Technical Regulations
Sec. 95.645 Control accessibility.
(a) No control, switch or other type of adjustment which, when
manipulated, can result in a violation of the rules shall be accessible
from the transmitter operating panel or from exterior of the transmitter
enclosure.
(b) An R/C transmitter which incorporates plug-in frequency
determining modules which are changed by the user must be certificated
with the modules. Each module must contain all of the frequency
determining circuitry including the oscillator. Plug-in crystals are not
considered modules and must not be accessible to the user.
http://www.futaba-rc.com/faq/service-faq.html#q198
How do I change the frequency on my receiver?
Futaba 72MHz receivers are all center tuned within 1/2 or the other 1/2 of the frequency band. So, if you have a receiver on any channel within 11-35 (72.010 through 72.490), you can purchase a receiver crystal and change it to any other channel within 11-35. If you have a receiver on any channel within 36-60 (72.510 through 72.990), you can change the crystal and use it on any other channel within 38-60. However, ALWAYS perform a full range check prior to utilizing the equipment. If you have any doubts about its performance, it is always best to send it for service and let us match your transmitter (if your Tx has a module, only that needs to be sent) and receiver for maximum performance
Futaba 27MHz, 50MHz, and 75MHz are all center tuned to that particular band. Therefore, any 27MHz receiver on any channel can be changed to any other channel WITHIN THE 27MHz band, and same is true of 50 and 75 MHz bands.
For info on changing to another FREQUENCY BAND (ie. changing a 72MHz receiver to 75MHz), please click here.
http://www.futaba-rc.com/faq/service-faq.html#q2
For a unit with crystals: We CANNOT recommend changing crystals to a different frequency. Changing the crystal on your transmitter is illegal unless you have the proper license. The FCC has established guidelines for the modeler's safety and for the safety of spectators. For safety and FCC reasons we must request that both TX and RX be sent to the service center to ensure proper crystal change and retuning to the new frequency. Crystal based radios cannot be converted to another band without parts replacement, and may not be able to be converted at all. Certain radios can be converted, for example, from 72 to 75MHz. Please contact the service center for any other conversions.
The applicable Federal Regulation is as follows:
TITLE 47--TELECOMMUNICATION COMMISSION (CONTINUED)
PART 95--PERSONAL RADIO SERVICES
Subpart E--Technical Regulations
Sec. 95.645 Control accessibility.
(a) No control, switch or other type of adjustment which, when
manipulated, can result in a violation of the rules shall be accessible
from the transmitter operating panel or from exterior of the transmitter
enclosure.
(b) An R/C transmitter which incorporates plug-in frequency
determining modules which are changed by the user must be certificated
with the modules. Each module must contain all of the frequency
determining circuitry including the oscillator. Plug-in crystals are not
considered modules and must not be accessible to the user.
http://www.futaba-rc.com/faq/service-faq.html#q198
How do I change the frequency on my receiver?
Futaba 72MHz receivers are all center tuned within 1/2 or the other 1/2 of the frequency band. So, if you have a receiver on any channel within 11-35 (72.010 through 72.490), you can purchase a receiver crystal and change it to any other channel within 11-35. If you have a receiver on any channel within 36-60 (72.510 through 72.990), you can change the crystal and use it on any other channel within 38-60. However, ALWAYS perform a full range check prior to utilizing the equipment. If you have any doubts about its performance, it is always best to send it for service and let us match your transmitter (if your Tx has a module, only that needs to be sent) and receiver for maximum performance
Futaba 27MHz, 50MHz, and 75MHz are all center tuned to that particular band. Therefore, any 27MHz receiver on any channel can be changed to any other channel WITHIN THE 27MHz band, and same is true of 50 and 75 MHz bands.
For info on changing to another FREQUENCY BAND (ie. changing a 72MHz receiver to 75MHz), please click here.
