Tx/Rx?
 

Hey Bax, I'm back to bother you again, actually it's most appreciated, but, I have another question for you: I just picked up (ebay) the <span class="Apple-style-span" style="font-family: Verdana, Arial; font-size: 13px; -webkit-border-horizontal-spacing: 1px; -webkit-border-vertical-spacing: 1px; ">Futaba R149 DP 9 channel PCM/PPM Rx that you had described as the replacement for the 129DP. I also got 6AEX AP/HP PCM/PPM Super Computer Tx. To the best of my knowledge, these are compatible. The Rx. has a channnel 19 crystal in it. I have heard that Futaba uses a dual rate crystal?, and the single ones won't work. Is that true for my current set-up? Could you give me the low-down on the dual rate crystals? Can I buy just one crystal for the radio that would match the one in the Rx. Thanks Again - Gorchew P.S. since they are are both which PCM/PPM compatible, which should I use- What are the advantages of each, or which is altogether better? ok , so it's more then one question - thanks</span>

RE: Tx/Rx?
 

Some 72Mhz Futaba receivers use Dual Conversion crystals and some use Single or Short Crystals.

A Dual Conversion receiver:
A type of receiver that converts the incoming frequency through two intermediate stages. This tends to eliminate the type of interference known as "image". With high-precision components, it also allows the receiver to be much more precise in selecting the incoming channel it accepts. This is what helps the receiver to be very narrow-band.

Single Conversion:
A single conversion receiver will only convert the incoming frequency one, thus it has a wider "window" for accepting RF.

A transmitter does not care if you are using a Single or Dual Rate receiver, thus as long as you are in the correct modulation (FM/PPM or PCM) either type will work fine.

You cannot buy a crystal for your radio and install it yourself if it is on anything other than the original channel your transmitter was tuned to. This is against FCC regulations. To change a transmitter to a different frequency, you will need to send it to an authorized service center to have this work done.


Sincerely,
Krysta
Product Development & Support Specialist
Futaba Service Center USA
[email protected]