what channel is this
06-17-2008 | 03:39 PM
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From: elkton,
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what channel is this
hi, i have a crystal set and i'm not sure what channel number it is. on the crystals it says, fm 72 mhz 72.730. i'm trying to figure out what channel it is, like 46,50,55. i need to get a flag for my remote and i need to know what numbers to buy. thanks guys
06-17-2008 | 04:36 PM
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From: elkton,
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RE: what channel is this
i'm talking about both. i have a set and want to use them. they work fine, but i need a channel flag for my remote. so everybody knows what channel i'm on. but i didn't know what numbers to get.
06-17-2008 | 04:45 PM
#4
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RE: what channel is this
It is illegal for the end user to change the crystal in the transmitter. These changes must be made by an authorized service shop.
If you are interested in the full text of the regulations concerning this matter they can be found at:
[link=http://www.access.gpo.gov/nara/cfr/waisidx_04/47cfr95_04.html]FCC Title 47, Part 95 - Personal Radio Services[/link]
Copied from Futaba's website
Copied from FCC regulations concerning this issue
If you are interested in the full text of the regulations concerning this matter they can be found at:
[link=http://www.access.gpo.gov/nara/cfr/waisidx_04/47cfr95_04.html]FCC Title 47, Part 95 - Personal Radio Services[/link]
Copied from Futaba's website
How do I change the frequency of my transmitter?
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.
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.
Copied from FCC regulations concerning this issue
[Code of Federal Regulations]
[Title 47, Volume 5]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR95.221]
[Page 539]
TITLE 47TELECOMMUNICATION CHAPTER IFEDERAL COMMUNICATIONS COMMISSION (CONTINUED)
PART 95_PERSONAL RADIO SERVICESTable of Contents
Subpart C_Radio Control (R/C) Radio Service
Sec. 95.221 (R/C Rule 21) How do I have my R/C transmitter serviced?
(a) You may adjust an antenna to your R/C transmitter and you may make radio checks. (A radio check means a one-way transmission for a short time in order to test the transmitter.)
(b) You are responsible for the proper operation of the station at all times and are expected to provide for observations, servicing and maintenance as often as may be necessary to ensure proper operation. Each internal repair and each internal adjustment to an FCC certificated R/C transmitter (see R/C Rule 9) must be made in accord with the Technical Regulations (see subpart E). The internal repairs or internal adjustments should be performed by or under the immediate supervision and responsibility of a person certified as technically qualified to perform transmitter maintenance and repair duties in the private land mobile services and fixed services by an organization or committee representative of users in those services.
(c) Except as provided in paragraph
(d) of this section, each internal repair and each internal adjustment of an R/C transmitter in which signals are transmitted must be made using a nonradiating (``dummy'') antenna. (d) Brief test signals (signals not longer than one minute during any five minute period) using a radiating antenna may be transmitted in order to:
(1) Adjust a transmitter to an antenna;
(2) Detect or measure radiation of energy other than the intended signal; or
(3) Tune a receiver to your R/C transmitter.
(Secs. 4(i) and 303(r), Communications Act of 1934, as amended, 47 U.S.C. 154(i) and 303(r), and sec. 553 of the Administrative Procedures Act, 5 U.S.C. 553) [48 FR 24890, June 3, 1983, as amended at 49 FR 20673, May 16, 1984; 63 FR 36610, July 7, 1998]
[Title 47, Volume 5]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR95.221]
[Page 539]
TITLE 47TELECOMMUNICATION CHAPTER IFEDERAL COMMUNICATIONS COMMISSION (CONTINUED)
PART 95_PERSONAL RADIO SERVICESTable of Contents
Subpart C_Radio Control (R/C) Radio Service
Sec. 95.221 (R/C Rule 21) How do I have my R/C transmitter serviced?
(a) You may adjust an antenna to your R/C transmitter and you may make radio checks. (A radio check means a one-way transmission for a short time in order to test the transmitter.)
(b) You are responsible for the proper operation of the station at all times and are expected to provide for observations, servicing and maintenance as often as may be necessary to ensure proper operation. Each internal repair and each internal adjustment to an FCC certificated R/C transmitter (see R/C Rule 9) must be made in accord with the Technical Regulations (see subpart E). The internal repairs or internal adjustments should be performed by or under the immediate supervision and responsibility of a person certified as technically qualified to perform transmitter maintenance and repair duties in the private land mobile services and fixed services by an organization or committee representative of users in those services.
(c) Except as provided in paragraph
(d) of this section, each internal repair and each internal adjustment of an R/C transmitter in which signals are transmitted must be made using a nonradiating (``dummy'') antenna. (d) Brief test signals (signals not longer than one minute during any five minute period) using a radiating antenna may be transmitted in order to:
(1) Adjust a transmitter to an antenna;
(2) Detect or measure radiation of energy other than the intended signal; or
(3) Tune a receiver to your R/C transmitter.
(Secs. 4(i) and 303(r), Communications Act of 1934, as amended, 47 U.S.C. 154(i) and 303(r), and sec. 553 of the Administrative Procedures Act, 5 U.S.C. 553) [48 FR 24890, June 3, 1983, as amended at 49 FR 20673, May 16, 1984; 63 FR 36610, July 7, 1998]
[Code of Federal Regulations]
[Title 47, Volume 5]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR95.222]
[Page 539-540]
TITLE 47TELECOMMUNICATION
CHAPTER IFEDERAL COMMUNICATIONS
COMMISSION (CONTINUED)
PART 95_PERSONAL RADIO SERVICESTable of Contents
Subpart C_Radio Control (R/C) Radio Service
Sec. 95.222 (R/C Rule 22) May I make any changes to my R/C station transmitter?
(a) You must not make or have anyone else make an internal modification to your R/C transmitter.
(b) Internal modification does not include:
(1) Repair or servicing of an R/C station transmitter (see R/C Rule 21, Sec. 95.221); or
(2) Changing plug-in modules which were certificated as part of your R/C transmitter.
(c) You must not operate an R/C transmitter which has been modified by anyone in any way, including modification to operate on unauthorized frequencies or with illegal power. (See R/C Rules 9 and 10, Sec. Sec. 95.209 and 95.210.)
[48 FR 24894, June 3, 1983, as amended at 63 FR 36610, July 7, 1998]
[Title 47, Volume 5]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR95.222]
[Page 539-540]
TITLE 47TELECOMMUNICATION
CHAPTER IFEDERAL COMMUNICATIONS
COMMISSION (CONTINUED)
PART 95_PERSONAL RADIO SERVICESTable of Contents
Subpart C_Radio Control (R/C) Radio Service
Sec. 95.222 (R/C Rule 22) May I make any changes to my R/C station transmitter?
(a) You must not make or have anyone else make an internal modification to your R/C transmitter.
(b) Internal modification does not include:
(1) Repair or servicing of an R/C station transmitter (see R/C Rule 21, Sec. 95.221); or
(2) Changing plug-in modules which were certificated as part of your R/C transmitter.
(c) You must not operate an R/C transmitter which has been modified by anyone in any way, including modification to operate on unauthorized frequencies or with illegal power. (See R/C Rules 9 and 10, Sec. Sec. 95.209 and 95.210.)
[48 FR 24894, June 3, 1983, as amended at 63 FR 36610, July 7, 1998]
[Code of Federal Regulations]
[Title 47, Volume 5]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR95.645]
[Page 561]
TITLE 47TELECOMMUNICATION
CHAPTER IFEDERAL COMMUNICATIONS
COMMISSION (CONTINUED)
PART 95_PERSONAL RADIO SERVICESTable of Contents
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.
[53 FR 36789, Sept. 22, 1988. Redesignated at 61 FR 28769, June 6, 1996, and further redesignated at 61 FR 46567, Sept. 4, 1996; 63 FR 36610, July 7, 1998]
[Title 47, Volume 5]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR95.645]
[Page 561]
TITLE 47TELECOMMUNICATION
CHAPTER IFEDERAL COMMUNICATIONS
COMMISSION (CONTINUED)
PART 95_PERSONAL RADIO SERVICESTable of Contents
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.
[53 FR 36789, Sept. 22, 1988. Redesignated at 61 FR 28769, June 6, 1996, and further redesignated at 61 FR 46567, Sept. 4, 1996; 63 FR 36610, July 7, 1998]
06-17-2008 | 04:50 PM
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From: elkton,
MD
RE: what channel is this
ok, so now i have a radio and receiver and crystal set i can't use. the bad part is they all work fine. the radio is new. what should i do now?
06-17-2008 | 04:54 PM
#6
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RE: what channel is this
You can send the radio and crystal to a shop and they can install it for you. You want to do this for more than just the "legal" reason. When a crystal is changed the radio must be retuned to optimize the output for the crystal. If not you can seriously reduce the range of the radio and jeapordize your plane. RCU member CGRetired recently purchased a radio that the original owner had changed the crystals on without having it retuned. When he sent it to the shop they told him that the output power was half of what it was supposed to be.
Yes, it is the law to do this. But aside from that, is crashing your plane worth the risk??
Ken
Yes, it is the law to do this. But aside from that, is crashing your plane worth the risk??
Ken
06-17-2008 | 04:59 PM
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From: elkton,
MD
RE: what channel is this
what shop would you use? would i need to send the receiver to? what does something like this cost? and no i don't think a plane is worth it or somebody. i won't put a plane in the air if i know something is amiss. i didn't realize that it made a difference.
06-17-2008 | 05:04 PM
#8
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RE: what channel is this
It depends on the brand, you can send it back to the manufacturer. Or you can use a reputable shop that works on all brands. IMHO the best out there is Radio South. [link]http://www.radiosouthrc.com/[/link]
On the pricing here is what their website lists
Since you already have the crystal I would guess it would cost less. My recommendation is to call them and ask the actual cost.
Ken
On the pricing here is what their website lists
FREQUENCY CONVERSIONS
The FCC requirements for "gold" is -55db sidebands at +/- 20Khz. An additional requirement is the frequency accuracy must be within +/- 1.5 KHz from center frequency. Most transmitters can be "gold stickered" at a cost of $15.00. Pro-Line systems are $40.00, due to special components needed to update them. Kraft systems are $50.00 for pre-1976 transmitters, and $25.00 for 1976 and later versions. Frequency changes are common in order to obtain a frequency that is less crowded or to move away from known interference at a local flying field. Costs vary from system to system, due to the price of crystals required for the change. Most newer systems use dual conversion crystals in the receivers. Prices vary, but most Dual Conversion systems are $49.50 (TX and RX, including tuning) to change. Single conversion systems are usually $39.50.
The FCC requirements for "gold" is -55db sidebands at +/- 20Khz. An additional requirement is the frequency accuracy must be within +/- 1.5 KHz from center frequency. Most transmitters can be "gold stickered" at a cost of $15.00. Pro-Line systems are $40.00, due to special components needed to update them. Kraft systems are $50.00 for pre-1976 transmitters, and $25.00 for 1976 and later versions. Frequency changes are common in order to obtain a frequency that is less crowded or to move away from known interference at a local flying field. Costs vary from system to system, due to the price of crystals required for the change. Most newer systems use dual conversion crystals in the receivers. Prices vary, but most Dual Conversion systems are $49.50 (TX and RX, including tuning) to change. Single conversion systems are usually $39.50.
Ken
06-17-2008 | 05:19 PM
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From: Bradenton, FL
RE: what channel is this
Or what channel did the transmitter have originaly? It should be marked somewhere on the transmitter. Then buy the proper crystals for both and you should be good to go.
06-17-2008 | 05:23 PM
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From: elkton,
MD
RE: what channel is this
thanks RCKen . the remote never had a crystal in it. it is a jr sport sx600. the only thing i see on it is 72 mhz, that's right under where the crystal goes in
06-17-2008 | 05:27 PM
#12
RE: what channel is this
ORIGINAL: traski
Or what channel did the transmitter have originaly? It should be marked somewhere on the transmitter. Then buy the proper crystals for both and you should be good to go.
Or what channel did the transmitter have originaly? It should be marked somewhere on the transmitter. Then buy the proper crystals for both and you should be good to go.
06-17-2008 | 07:48 PM
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RE: what channel is this
ORIGINAL: Live Wire
AMA has a list of Numbers you can compare to. Saves a lot of time and insults
AMA has a list of Numbers you can compare to. Saves a lot of time and insults
Channel 11 72.010 MHz
Channel 12 72.030 MHz
Channel 13 72.050 MHz
Channel 14 72.070 MHz
Channel 15 72.090 MHz
Channel 16 72.110 MHz
Channel 17 72.130 MHz
Channel 18 72.150 MHz
Channel 19 72.170 MHz
Channel 20 72.190 MHz
Channel 21 72.210 MHz
Channel 22 72.230 MHz
Channel 23 72.250 MHz
Channel 24 72.270 MHz
Channel 25 72.290 MHz
Channel 26 72.310 MHz
Channel 27 72.330 MHz
Channel 28 72.350 MHz
Channel 29 72.370 MHz
Channel 30 72.390 MHz
Channel 31 72.410 MHz
Channel 32 72.430 MHz
Channel 33 72.450 MHz
Channel 34 72.470 MHz
Channel 35 72.490 MHz
Channel 36 72.510 MHz
Channel 37 72.530 MHz
Channel 38 72.550 MHz
Channel 39 72.570 MHz
Channel 40 72.590 MHz
Channel 41 72.610 MHz
Channel 42 72.630 MHz
Channel 43 72.650 MHz
Channel 44 72.670 MHz
Channel 45 72.690 MHz
Channel 46 72.710 MHz
Channel 47 72.730 MHz
Channel 48 72.750 MHz
Channel 49 72.770 MHz
Channel 50 72.790 MHz
Channel 51 72.810 MHz
Channel 52 72.830 MHz
Channel 53 72.850 MHz
Channel 54 72.870 MHz
Channel 55 72.890 MHz
Channel 56 72.910 MHz
Channel 57 72.930 MHz
Channel 58 72.950 MHz
Channel 59 72.970 MHz
Channel 60 72.990 MHz
Ken
06-18-2008 | 11:58 AM
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From: Oklahoma City,
OK
RE: what channel is this
So is it bad that I pulled the crystals out of the back of the other JR sport radio I had because I wanted to use the newer one in my plane? Is that actually illegal? I know guys that switched all the time when I was racing cars so that there weren't interference issues. Can I just stick the original crystals back together and switch receivers out to make it right?
06-18-2008 | 12:04 PM
#17
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RE: what channel is this
What's illegal is swapping or changing the crystal in the TRANSMITTER. You just can't do that, even with radios of the same brand, type, model, and frequency. They still have to be adjusted because, as stated, the crystals are not exactly alike. Even minor adjustments to prevent splattering over to an adjacent channel are absolutely necessary and this has to be done, must be done, by an FCC approved facility.
The reason this is such a big deal for transmitters should be obvious. However, I will explain. The receiver does not put out RF energy, or power, into the air. The transmitter does. So, it must be right on frequency, on the center of it's band, to operate on either side of the band, within it's bandwidth. To explain further.. bandwidth is the bottom and top frequency limit of operation of a specific transmitter.
FOR EXAMPLE (emphasis because this IS an example for simplification)
If that is 20,000 hertz, for instance, then the center would be 10,000 hertz so that it has 10,000 on the bottom side and 10,000 on the top side. If the crystal is off, then the bandwidth is still 20,000 hertz, however, if the center is off, to say 12,500 hertz, then it only has 7500 on the top and 12,500 on the bottom. It will spill outside of the high limit of 20,000 to 22,500 hertz and cause inteference with the operation of the next band which may be 30,000 which has a bottom of 20,000 and a top of 40,000. You can see that the 22,500 is operating within the band of the next frequency band which operates between 20,000 and 40,000 hertz. This what is not allowed, and can cause inteference between adjacent bands... not good.
CGr.
The reason this is such a big deal for transmitters should be obvious. However, I will explain. The receiver does not put out RF energy, or power, into the air. The transmitter does. So, it must be right on frequency, on the center of it's band, to operate on either side of the band, within it's bandwidth. To explain further.. bandwidth is the bottom and top frequency limit of operation of a specific transmitter.
FOR EXAMPLE (emphasis because this IS an example for simplification)
If that is 20,000 hertz, for instance, then the center would be 10,000 hertz so that it has 10,000 on the bottom side and 10,000 on the top side. If the crystal is off, then the bandwidth is still 20,000 hertz, however, if the center is off, to say 12,500 hertz, then it only has 7500 on the top and 12,500 on the bottom. It will spill outside of the high limit of 20,000 to 22,500 hertz and cause inteference with the operation of the next band which may be 30,000 which has a bottom of 20,000 and a top of 40,000. You can see that the 22,500 is operating within the band of the next frequency band which operates between 20,000 and 40,000 hertz. This what is not allowed, and can cause inteference between adjacent bands... not good.
CGr.
06-18-2008 | 12:19 PM
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RE: what channel is this
That's some good info to know, I had no clue that that could happen. Seems like another good reason to switch to 2.4. Thanks for the information!
06-18-2008 | 08:02 PM
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From: Jackson,
MI
RE: what channel is this
I think what brett65 was asking about was more concerning ground use radio systems. Before you say it, I am aware that it is still "illegal" to swap Tx crystals, however it was a common practice at all the races I went to. The reduced range was not a problem becauce the vehicles were right in front of us. This is much more critical with aircraft as they typically use much more of thier available range.
06-18-2008 | 08:13 PM
#22
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RE: what channel is this
I realize that the car guys do this all the time. But worrying about this has more to do with just reduced range on the transmitter. The bigger picture is that it could get the user in trouble with the FCC. All of the frequencies we use are sandwiched between frequencies used for commercial purposes. If a RC user chances his crystal without retuning and it bleeds over on the commercial frequencies that user could face very steep fines from the FCC.
Ken
Ken
06-19-2008 | 08:30 AM
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From: Jackson,
MI
RE: what channel is this
Not disagreeing with you Ken, But what are the chances of an R/C system actually causing interference with an industrial system? Don't they operate on much higher power output than our systems? Not trying to argue that it is OK or anything, just curious about the real chances for screwing up an industrial system. I used to run a radio controlled, truck mounted crane at one of my jobs.
06-19-2008 | 08:39 AM
#24
RE: what channel is this
TV transmitters do but things like crane remote controls and the like do not. Some use other bands like http://www.remtron.com/ but not all. Would you want to cause a crane to drop its load?
06-19-2008 | 08:40 AM
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RE: what channel is this
ORIGINAL: Darkbird
Not disagreeing with you Ken, But what are the chances of an R/C system actually causing interference with an industrial system? Don't they operate on much higher power output than our systems? Not trying to argue that it is OK or anything, just curious about the real chances for screwing up an industrial system. I used to run a radio controlled, truck mounted crane at one of my jobs.
Not disagreeing with you Ken, But what are the chances of an R/C system actually causing interference with an industrial system? Don't they operate on much higher power output than our systems? Not trying to argue that it is OK or anything, just curious about the real chances for screwing up an industrial system. I used to run a radio controlled, truck mounted crane at one of my jobs.
Ken
