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

Receiver AM crystal in Frequency module ?

Reply
Old 07-02-2003, 12:21 AM
  #1
A Fun Flyer
Thread Starter
 
Join Date: Jan 2002
Location:
Posts: 7
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Receiver AM crystal in Frequency module ?

I would like to change the channel of an
AM Futaba frequency module (FP-TF-AM) from
Channel 42 to 46.
I was wondering if the AM TX crystal is different from the
AM RX crystal. Towerhobbies carries only receiver am crystal.
Can I use an AM RX crystal in the AM frequency module (TX)

Thanks,
B.
A Fun Flyer is offline  
Reply With Quote
Old 07-02-2003, 01:42 AM
  #2
strato911
 
Join Date: Sep 2002
Location: West Jordan, UT
Posts: 1,479
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Receiver AM crystal in Frequency module ?

Transmitters don't work with receiver crystals, and receivers don't work with transmitter crystals, AM or FM.

There is a difference in actual crystal frequency between Tx and Rx crystals
strato911 is offline  
Reply With Quote
Old 07-02-2003, 03:45 AM
  #3
A Fun Flyer
Thread Starter
 
Join Date: Jan 2002
Location:
Posts: 7
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Receiver AM crystal in Frequency module ?

Thanks for your reply.
Where can I get Futaba AM transmitter crystal?
Does the Hitec transmitter crystal work?

Thanks,
B.
A Fun Flyer is offline  
Reply With Quote
Old 07-02-2003, 03:58 AM
  #4
JohnBuckner
 
JohnBuckner's Avatar
 
Join Date: Dec 2001
Location: Kingman, AZ
Posts: 10,323
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Receiver AM crystal in Frequency module ?

Just for the record since you don,t give your location, In the US it is aginst FCC regulation to change a Tx crystal in either the transmitter or a Tx module without a realignment.

John
JohnBuckner is offline  
Reply With Quote
Old 07-02-2003, 07:18 PM
  #5
ReallyUglyStick
 
Join Date: Feb 2002
Location: Cary, NC
Posts: 207
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Receiver AM crystal in Frequency module ?

just buy a new transmitter module. you may have to hunt for it, but they're available.
ReallyUglyStick is offline  
Reply With Quote
Old 07-02-2003, 07:34 PM
  #6
KG4MIN
 
Join Date: Apr 2002
Location: Pensacola, FL
Posts: 23
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default AM xtal

Exchange the crystal you have. $5

http://members.aol.com/davthacker/ra...lexchange.html
KG4MIN is offline  
Reply With Quote
Old 07-02-2003, 07:41 PM
  #7
ReallyUglyStick
 
Join Date: Feb 2002
Location: Cary, NC
Posts: 207
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Receiver AM crystal in Frequency module ?

as stated above, you can't legally change the tx crystal in the US. also, he's dealing with a modular radio, not a standard crystal.
ReallyUglyStick is offline  
Reply With Quote
Old 07-02-2003, 09:20 PM
  #8
KG4MIN
 
Join Date: Apr 2002
Location: Pensacola, FL
Posts: 23
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Xtal

Never said he would be legal in doing so. I guess all the crystals sold on the website I gave are for persons with the proper training, license, and equipment necessary to properly align the module to the new frequency. And then again maybe not.
KG4MIN is offline  
Reply With Quote
Old 07-03-2003, 06:33 AM
  #9
golf_lake
 
Join Date: Sep 2002
Location: Adelaide
Posts: 78
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Receiver AM crystal in Frequency module ?

To answer your question, you cannot use a receive RX in a TX or vicea-versa . Reason being the TX crystal run at the frequency that is specified on it and the RX crystal operates on that frequency +/- the intermediate frequency.

Your second Question about using a crystal from a different manufacturer would not be recommended either, without knowing that they are a direct equivalent replacement. Reason being the way the crystal is cut originally, they can/are cut to operate on fundamental or overtone and then you must consider if they (the Manufacturer) use High or Low side mixing.
WARNING while it may appear to work with the wrong type of crystal, it may not be working properly giving you reduced range and interfering with other services.

Now the legal warnings, the laws of the land you live in apply to all equally, it is not illegal for you to sell or buy crystals, it only becomes illegal when a non qualified person does modifications to a TX and turns it on. This includes swapping crystals in the US and possibly some other countries.

I have not read through the hole of the FCC rules to find the penalties, but here in Oz the penalties are very severe for offences under the Telecommunication Act, and if the authorities wanted to make an example of you, you would not be flying or doing anything for a long time. Using the excuse they sold it to me will not be considered as a defence.
golf_lake is offline  
Reply With Quote
Reply


Thread Tools
Search this Thread
Display Modes

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



All times are GMT -8. The time now is 09:58 PM.