TX/RX Mixing
01-28-2009 | 04:35 AM
#2
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From: england, UNITED KINGDOM
RE: TX/RX Mixing
Hi
It will work with other makes of reciever along as you using ppm mode.
Just make sure whatever reciever you use has its own make of crystal, not a
Jr one (unless thats whats recomended for the given make).
You still will need to use a Jr crystal for the transmitter.
Simon
It will work with other makes of reciever along as you using ppm mode.
Just make sure whatever reciever you use has its own make of crystal, not a
Jr one (unless thats whats recomended for the given make).
You still will need to use a Jr crystal for the transmitter.
Simon
01-28-2009 | 12:39 PM
#4
RE: TX/RX Mixing
Not true. You also have to be of the same shift in the U.S. unlike in the U.K. Many manufacturers do offer RX's in either shift, shift selectable or auto-shift versions. You can find the correct tyoe but study the mfg data carefully.
01-28-2009 | 02:17 PM
#5
RE: TX/RX Mixing
You also can not legally change your own TX crystal in the U.S.
Simon - Please don't quote UK regs/procedures to people in the U.S. as they don't need to break the law.
Simon - Please don't quote UK regs/procedures to people in the U.S. as they don't need to break the law.
01-28-2009 | 02:33 PM
#6
RCU Forum Manager/Admin
My Feedback: (9)
RE: TX/RX Mixing
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
[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]
01-28-2009 | 03:30 PM
#7
RE: TX/RX Mixing
ORIGINAL: harmsway
Will a JR EP7202 TX work with other brands of receivers?
All comments appreciated,
Thanx
Will a JR EP7202 TX work with other brands of receivers?
All comments appreciated,
Thanx
There are a number of other, not quite as common, brands of 72Mhz FM/PPM receivers on the market that would also come in versions compatible with your JR transmitter including Corona, Berg, Sombra Labs, e.g. The main feature to assure compatibility with a JR transmitter is either auto-shift/shift selectability or simply a positive shift model of receiver.
Futaba/Tower Hobbies brand transmitters use negative shift by default. Futaba, Tower Hobbies, or Hobbico brand FM receivers do not generally feature shift selectability and will not generally be compatible with your JR 72Mhz transmitter.
72Mhz PCM receivers, like 2.4Ghz receivers, use prioprietary digital signalling schemes and are only compatible with like brands of transmitters. You could not, for example, use an Airtronics PCM receiver with your JR transmitter in PCM mode, even though they use the same shift selection. The digital signaling schemes are different between Airtronics PCM equipment and JR PCM equipment, and they will not work together.
For glow powered sport planes, two of my favorite receivers are the GWS RD8SL or the Hitech Supreme IIS. These are both 8-channel full range dual conversion receivers of excellent quality and modest cost. The Hitec Supreme IIS normally sells for $39.99 plus crystal and will autodetect the shift mode of your transmitter. The GWS RD8SL is available for $24.99 plus crystal from Hobby King/Hobby City, and is shift selectable to either positive or negative shift.
I've used both of these excellent receivers with my Futaba 7CAF transmitter in fast sport planes at fairly significant distances. Both models perform beautifully and are at least as reliable as the much more expensive Futaba receivers I've used.
01-28-2009 | 03:42 PM
#8
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From: Emmaus,
PA
RE: TX/RX Mixing
JR and Airtronics are typically positive shift, and Futaba and Hitec are typically negative shift. If you have a JR TX, then be sure to get a receiver that is positive-shift, auto-shift, or shift selectable. Hitec makes several RXs that will work with JR TXs:
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXCXM9&P=7]Electron-6 (JR/Airtronics version)[/link]
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXKYK1&P=7]Mini 6S (Auto shift)[/link]
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXRSS1&P=7]Neutron-6 (Auto shift)[/link]
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXKYK3&P=7]Supreme IIS (Auto shift)[/link]
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXCXM9&P=7]Electron-6 (JR/Airtronics version)[/link]
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXKYK1&P=7]Mini 6S (Auto shift)[/link]
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXRSS1&P=7]Neutron-6 (Auto shift)[/link]
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXKYK3&P=7]Supreme IIS (Auto shift)[/link]
01-28-2009 | 09:08 PM
#9
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From: Newaygo, MI
RE: TX/RX Mixing
Hi Guys,
Thank-you all for your input. I've certainly learned alot about something I never new exsisted. Things have changed over the past 30 years.
Thanx again to all.
Harmsway
Thank-you all for your input. I've certainly learned alot about something I never new exsisted. Things have changed over the past 30 years.
Thanx again to all.
Harmsway
01-29-2009 | 05:29 AM
#10
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From: england, UNITED KINGDOM
RE: TX/RX Mixing
Hi
I don't believe i even suggested changing the transmitter crystal, however if i lived in america i'm sure i would ignore that ridiculous rule.
Simon
I don't believe i even suggested changing the transmitter crystal, however if i lived in america i'm sure i would ignore that ridiculous rule.
Simon
01-29-2009 | 10:13 AM
#11
RE: TX/RX Mixing
ORIGINAL: simhatus
Hi
I don't believe i even suggested changing the transmitter crystal, however if i lived in america i'm sure i would ignore that ridiculous rule.
Simon
Hi
I don't believe i even suggested changing the transmitter crystal, however if i lived in america i'm sure i would ignore that ridiculous rule.
Simon
