RC Radios, Transmitters, Receivers, Servos, gyros Discussion all about rc radios, transmitters, receivers, servos, etc.

Can I use a Rx crystal on a Transmitter?

Reply

Old 08-26-2006, 11:08 AM
  #1  
rodz666
Junior Member
Thread Starter
 
Join Date: Aug 2006
Location: , BRAZIL
Posts: 1
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Can I use a Rx crystal on a Transmitter?

Can I use a Rx crystal on a Transmitter? I misplaced the transmitter crystal but I got 2 rx crystals!!
rodz666 is offline  
Reply With Quote
Old 08-26-2006, 11:18 AM
  #2  
Tall Paul
Senior Member
 
Join Date: Jun 2002
Location: Palmdale, CA
Posts: 5,211
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Can I use a Rx crystal on a Transmitter?

Won't work.
Tall Paul is offline  
Reply With Quote
Old 08-26-2006, 12:39 PM
  #3  
RCKen
RCU Forum Manager/Admin
My Feedback: (9)
 
RCKen's Avatar
 
Join Date: Jul 2002
Location: Lawton, OK
Posts: 27,094
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Can I use a Rx crystal on a Transmitter?

No, they won't work. In fact, it's illegal for the end user to change the frequency of transmitters in the United States.

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.

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 47--TELECOMMUNICATION CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION (CONTINUED)
PART 95_PERSONAL RADIO SERVICES--Table 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 47--TELECOMMUNICATION
CHAPTER I--FEDERAL COMMUNICATIONS
COMMISSION (CONTINUED)
PART 95_PERSONAL RADIO SERVICES--Table 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 47--TELECOMMUNICATION
CHAPTER I--FEDERAL COMMUNICATIONS
COMMISSION (CONTINUED)
PART 95_PERSONAL RADIO SERVICES--Table 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]
RCKen is offline  
Reply With Quote
Old 08-26-2006, 01:12 PM
  #4  
Rodney
Senior Member
 
Join Date: Dec 2001
Location: FL
Posts: 7,769
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Can I use a Rx crystal on a Transmitter?

A receiver crystal for any specific channel is not exactly on that frequency. If dual conversion receiver the frequency is 11.7 MHZ different, if single conversion 455KHZ different. Besides, most transmitters operate with a crystal way below the transmitted frequency as the oscillator amplifies a harmonic of the crystal for transmission, usually an odd harmonic.
Rodney is offline  
Reply With Quote
Old 08-26-2006, 01:29 PM
  #5  
Scar
My Feedback: (3)
 
Scar's Avatar
 
Join Date: Oct 2002
Location: Peoria Hts, Il. IL
Posts: 3,120
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Can I use a Rx crystal on a Transmitter?


ORIGINAL: RCKen

No, they won't work. In fact, it's illegal for the end user to change the frequency of transmitters in the United States.

If you are interested in the full text of the regulations concerning this matter they can be found at:<<snip>>
Isn't this the classic troll? And did you notice the troller claims a Brazilian location?

Let it go.
Dave Olson
Scar is offline  
Reply With Quote
Old 08-26-2006, 04:55 PM
  #6  
RCKen
RCU Forum Manager/Admin
My Feedback: (9)
 
RCKen's Avatar
 
Join Date: Jul 2002
Location: Lawton, OK
Posts: 27,094
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Can I use a Rx crystal on a Transmitter?


ORIGINAL: Scar


ORIGINAL: RCKen

No, they won't work. In fact, it's illegal for the end user to change the frequency of transmitters in the United States.

If you are interested in the full text of the regulations concerning this matter they can be found at:<<snip>>
Isn't this the classic troll? And did you notice the troller claims a Brazilian location?

Let it go.
Dave Olson
Dave,
You are completely correct. I missed that. But then again it was early this morning and I hadn't have enough coffee yet!!!

Ken
RCKen is offline  
Reply With Quote

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service