S/D Conversion
 

Quick-fire question

whats the difference and advantage between single and dual conversion crystals?

RE: S/D Conversion
 

The question should be "What is the advantage between a dual or single conversion receiver" as crystals are not classified as either. A crystal is just a block of quartz cut to resonate at a particular frequency. Now, dual conversion receivers require a crystal that is about 10.7 MHZ different than the transmitted signal, either more or less depending on the shift you want in the receiver. Single conversion crystals are 455 KHZ different in frequency from the transmitted signal. You usually need to also buy the crystals to match the brand of receiver, i.e. JR crystals for a JR receiver, a Futaba crystal for a Futaba receiver etc. Different design of the receiver oscillator circuits may require a different cut on the crystal, X, Y, Z or ??? depending on the electrical design of the oscillator in the receiver.

RE: S/D Conversion
 

erm...

there were some words in there i dont understand...

in plain english, what are the advantages? (lol, im only simple kid)

RE: S/D Conversion
 

dual conversion receiver:

Longer range
Substantially less chance of interference (hits - ie losing your plane )


Single conversion receiver:

OK for in close flying (park flyer type )
Much less range AND SUBSTANTIALLY higher chances of interference at much over 500 - 600 '

That is the basic difference. There are a FEW exceptions to the interference/hits (Berg receivers is the primary exception ), however, I would not recommend ANY single conversion receiver for a glow powered plane since the range the plane flys at is usually substantially more than an electric.

RE: S/D Conversion
 

In terms I understand, single conversion means the incoming signal is filtered for “noise” one time before going the rest of the way through the receiver and dual conversion means it is filtered twice. That may not be technically correct but it means more to me than KHZ numbers.

Hitec & Futaba micro receivers for limited range park flyers are single conversion. Their full range receivers are dual conversion. I’m guessing it takes more parts (weight) to do dual conversion and they don’t do it for the stuff that has to be super light.

From what I’ve read, all JR receivers are single conversion; and they use some other technology to deal with “noise.”

Since Futaba & JR are both widely used all over the world, in big and expensive planes, I’m not sure that either method is “better” than the other.