rob.l

My Feedback: (1)

Sorry newbie here......
Ive hear people talking on the board about tunning up crystals. Does the frequency change over time? Is this a common thing? I just bought a used JR Transmitter XP652 and put in a set of GWS crystals that I had. They are the micro crystals, to fit into a GWS pico receiver. Its not working for some reason, so I was wondering whether it may be the crystals. If this is true that they can be serviced...Where would one take them?

One more thing, Are the GWS crystals different for Futaba and JR transmitters?
Also my Transmiter is a 6ch and the GWS pico reciever is a 4 ch. Will they work together??

Thanks
Rob

smokingcrater

first of all, you need to generally use crystals from the same manufacturer. second, radios are tuned for not only a specific frequency, but a specific crystal. the only way you can retune it is to send it in to the factory for retuning.

JohnBuckner

My Feedback: (1)

Smokingcrater is absolutely correct, never use crystals of a different brand than the Rx you are plugging it into. Not all crystals are cut the same even though of the same channel.

Also and this is what is your biggest issue Tx and Rx crystals cannot interchange, a Rx crystal will not work in a Tx or the other way around.

Another issue you cannot use single conversion crystals in a dual conversion Rx. Not sure which Rx you are using, you never said.

Last major issue is do not switch crystals in a tx with out sending in for a retune. It is aginst FCC regulation. If you have a module type Tx you can swap the module for one of a differant channel or with syth types dial in a differant channel.

John

EDIT: Just noticed you are from Canada and of course our FCC regulations would not apply to you however I beleve the approriate agency in your country also uses similar regulations in this regard you may want to check with your national modeling organization.

rob.l

My Feedback: (1)

Thanks.. It looks like I am off to find a new JR receiver so I can run the existing crystals that are with the radio. I was hopeing to us a pico receiver that I had, but it doesnt look like this is the case.

One more question. The only plane I own right now is a trainer,a electric J-3 Cub. My radio is a 6ch JR XP652, when shopping for a new receiver should I only get a 6ch receiver or can I get away with a 4ch for the cub? I guess I am worried about size and weight.

Thanks
Rob

staggerwing

My Feedback: (5)

Why not get the proper receiver crystal to match your transmitter for your four channel receiver? Would be cheaper than buying a new receiver. Yes, your four channel reciever will work with the JR transmitter. You will have the first four functions, throttle, aileron, elevator and rudder. Make sure that your four channel receiver shift is compatible with the JR transmitter. JR and Airtronics has a positive shift on the transmit frequency and Futaba and Hitech (most-some have swtichable) have negative shift.

Rich

blikseme300

My Feedback: (118)

Crystal oscillating frequency is typically NOT the frequency printed on the sticker/decal. All the sticker/decal indicates is that the receiver will be in tune for the printed frequency when used in the type it was made for.

As a rule, NEVER mix different manufacturers crystals and equipment. Be sure that what you want to use is the recommended part. Even if the manufacturer is the same the crystal won't work correctly if types are mixed. Example: Futaba AM & FM, single conversion & dual conversion.

Using crystals that are not specifically matched to the equipment is very irresponsible. Trying to save a few bucks could cost a life. The same goes for changing the TX crystals yourself. If at all unsure, send the units in to a service center. Rather safe than sorry.

Safe Flying!

FredRasener

I am a bit confused here. When I get a receiver and crystal they come in seperate packages.
Does Tower or ServoCity or whomever tune the
receiver to that specific crystal and them remove it to ship the two??????

Just a newbie question.

dant-RCU

My Feedback: (3)

Receivers are initially set at the factory/distributor. When you get one from Tower/Servo City/etc you get the receiver and crystal you wanted. If it is a Futaba receiver it will be a factory-set low-band or high-band receiver depending on the frequency. Receivers are not really tuned after you receive them unless there is a problem or a crash or something and you send it in for service.

Transmitters ARE tuned to a specific crystal and frequency. If you change the crystal (yes, illegial for non-certified types in the US to do so) then that Tx is supposed to be tuned (re-tuned) to that crystal/frequency.

Dan