Newbie Crystal Question

[callawaymax]

Hi,

I just bought a new Futaba 3PK Radio and I want to use 75mhz crystals. I have 3 RC trucks with all having the 75mhz receivers.

I want to buy a crystal set so that so that I can use the transmitter for all 3 cars without having to change the crystal in my transmitter everytime. So that means that I need 4 identical 75mhz crystals, right?

Also, could someone explain to me what this high-band, 75Mhz FM, 75Mhz AM, Short, and Dual Conversion? I'm kind of lost here.

Also, when buying crystals, is there a range that's generally popular that I should stay away from or are they all pretty much the same?

Thanks in advance,
CallawayMax

 

[vjeltz]

I'm new here, but I was looking at the exact same radio. Correct me if I'm wrong guys, but doesn't the 3pk synthesize its frequency therefore not needing crystals? I assume you can use it with any existing FM receiver by dialing in the frequency of your current crystals.
I am still wondering about the AM add-on that let's you dial in AM receivers. Does the AM receiver have to be on the same band as your 3pk (27 MHz Vs 75 MHz) or can the 3pk change bands?

 

[Çh®i§tiªñ]

FUTJ32** 3PK 27 & 75 mhz R203HF RX – FM/HRS Modulation
FUTJ33** 3PK 27 & 75 mhz R113iP RX – PCM Modulation

First off, which one of the 2 models did you get?

Both of these require crystals - they do not make a no crystal version YET. However, if you use the HiTec Spectra module it WILL work. Although there is some reason the FCC doesn't condone it because they were not made for eachother. Oddly enough, Futaba made their radio to accept the module PERFECTLY! lol

Yes, just match up the RX crystals to be the same as your TX crystals.

However, if you have the HRS system, the #1 thing to make sure of is that you have just HRS receivers and ONLY digital servos....

You can change the mode on the tx from HRS/PCM/PPM so you can use standard FM receivers. You just need to make sure you have the right model.

 

[dougc]

ok callawaymax i might be wrong but u are right , for example. if all of your cars have 75.00 then just shove on in the radio and it will work just rember never to turn them all on at the same time...now if it is a synthesize one u can use differnt frequencys crystals in your car, and program your radio for those cars ex.
car 1 75.84
car 2 75.25
and u can have to so it know what care uses what number.
i hope this makes since.