faisalk

I just bought my 2nd plane and have a futaba receiver lying around which I plan to use. Is it ok to use it with JR transmitter? also can JR frequency crystals be used with futaba receivers?

TTARK

In short you cannot use Jr transmitters with futaba receivers and vice versa. The difference is in the pos and neg shift so they wont work together. You cannot use JR crystals with Jr gear either they just wont work

Terry

faisalk

Hmmmm.... but I connected the servos to the receiver(servos are also futaba) and they respond perfectly to my JR transmitter. The only thing I'm worried about is that is it a reliable setup to risk a new plane?

MikeL

My Feedback: (3)

It's only in North America that their PPM receivers are incompatible. If they use the same phase shift in Pakistan, then go for it. PCM receivers aren't compatible between brands.

raymcm

As a rule, you should always use Futaba crystals in Futaba rx and JR crystals in JR rx regardless of the tx being used.

Sometimes you can get away with interchange but the range can be seriously reduced and cross channel interferance increased.

I know for a fact that you cannot interchange Futaba and Hitec but not sure about JR

faisalk

I am sorry Mike I dint get u. I bought my radio system frm UK and they use 35mhz frequency. And am using my JR at PPM.

HarryC

My Feedback: (1)

With UK radios we use Futaba with JR all the time. It is totally reliable. As a previous post said, the only rule that you must obey is a Futaba crystal in Futaba equipment and a JR crystal in JR equipment.

Harry

Forgues Research

My Feedback: (7)

If the radios don't come from North America, because of the positive and negative shift. but I beleive anywhere else, it is compatible.

faisalk

Harry. So is it safe to use a Futaba receiver and futaba servos with a JR transmitter? the only thing I am woorried about is if the range will be affected or anything? Also I am using JR receiver crystal in that Futaba receiver. It seems to work fine. You think its ok? or I should buy a Futaba receiver crystal to use with my Futaba receiver, but then my transmitter will have a JR crystal.

Ed_Moorman

My Feedback: (1)

The shift is the same for ham frequencies, even in North America. It is only the 72 MHz freqs that are different.

Steve Lewin

On 35MHz, using Futaba with JR is fine. The only thing that might mess up your range is using the wrong crystal. You should use the correct Futaba crystal in the receiver. I guess it is a single conversion receiver or the JR crystal wouldn't even *seem* to be working.

As several people have now told you the crystal should always match the equipment it's in. JR transmitter = JR crystal, Futaba receiver = Futaba crystal. That's the only safe way to go.

Steve

LSP972

My Feedback: (13)

A fascinating discussion.

Now; does anyone know WHY the US (72 mHz) stuff has been made incompatible with each other?

One has thoughts of nefarious marketing ploys, etc. Or perhaps it is as simple as an edict by the FCC.

Anyone know?

Lynx

Marketting. That's the only reason.

faisalk

so is it ok to use jr crystal in transmitter and futaba crystal in receiver? will they both work fine rather than having jr crystal in receiver too?

Forgues Research

My Feedback: (7)

You use a Futaba crystall for a Futaba product, and a JR crystall in a JR product.

PilotFrog

Most JR receivers in the US are single conversion and most Futaba are dual conversion, both ppm and pcm, so the xtals will not work when interchanged even if they are on the same channel in the 72 Mhz. band. And even if they are the same conversion type it is a bad idea to swap xtals between makes.
PilotFrog

MO_Radio_Tech

Don't want to step on any toes or contradict anyone here, but some things I just read here are strange. I can tell you from staring at 1000's of JR RF carriers that all JR equipment authorized for sale in the USA (PPM,PCM)has the same modulation shift regardless of band. (27,50,53,72,75)

For FM/PCM it has always been this way. The original founders of Japan Radio were engineers from Airtronics. That is why the modulation shift has always been compatible between JR and AT.

I am no expert on anything overseas. In Europe, JR has a special thing going with Graupner that does not exist elsewhere, so nothing would surprise me.

Not usually a good idea to swap rocks between brands. I would not recommend it. Crashing a $500 dollar plane over a $15 crystal.

J0E

You are correct, all JR stuff is on the same shift (positive) regardless of band. It is the futaba stuff (and some others) that are negative for 72mhz and above and positive for less than 72mhz. Hence all the brands are compatible in countries that use bands lower than 72mhz.

HarryC

My Feedback: (1)

MO-Tech, it is Futaba that does the dirty on you in the USA, not JR, which is why all the JR stuff you see is the same shift.

Futaba makes same shift radio as everyone else for the whole of the rest of the world. Futaba deliberately makes incompatible equipment just for North America. Nice company eh?

H

Forgues Research

My Feedback: (7)

I beleive its not a different shift under 72mgz because in France they use also 72 mgz (different then North America) and it is also the same shift as all the others but not here in North Amirica.

MO_Radio_Tech

Believe me, I am pro JR. I think the other brands are good too, but I am mostly a JR man.

I do not know what games companies play in the rest of the world.