I have a radio (channel 18) and a reciever (channel 5), if I put a channel 18 crystal in the channel 5 reciever will they become compatible?

Thanks, Dave Trimmer

Yes, as long as the receiver is compatible with the transmitter you will be fine by changing the crystal in the receiver.

Ken

There are alot of varibles that need to be explored befor awnsering the question. Are the radio transmitter and the reciever compatable, ie are both Futaba or Futaba and a Hitech that is designed for Futaba. Are they both FM, AM, or PCM? Just a few thoughts. If they do match up I would do a rather complete range check and vibration test befor flying. Hope this helps, Dave

how do you tell if the transmitter is cmpatible with the reciever?

Edit: this was supposed to be the 3rd post because I type to slow.

Yes,

Assuming they have the same shift and are both 72MHZ FM. You should buy crystal for that particular RX from a dealer. They are usually 5-7$ unless you have something unusual. Post the brands of the units and people can be more helpful. (That reminds me, I need to order a crystal for an RX I got from a friend of mine).

Later,

Mark

Compatibility for PPM type signals is denoted by the "shift". Futaba and (much of) Hitec uses negative shift. JR and I believe Airtronics use positive shift. Some companies make positive or negative versions of their receivers. There is also something called PCM, but these are more expensive, I suspect if you had those, you would know it. So, what brand and model do you have for transmitter and receiver?

My transmitter is an airtronics and my reciever is an old style airtronics reciever but want to buy a new style reciever so I wont have to buy as many adapters (7 servos on one and 3 on the other therefore I will only need 3 adapters over seven adapters and a new reciever from an unknown compay.(going to toledo ohio to pick one up)).[&:]confusing for you eh!

Dave,
You'll be fine with either type of airtronics receivers. Just make sure that the cyrstal you use in the receiver is for the proper type of receiver (old or new) because they are different.

Ken

Is there a channel 5 on the 72MHZ area? I believe the lowest is either 10 or 11-have to look to be sure. Now there is a channel 5 in the 27MHZ area but there is no way you can put a 72 MHZ crystal in that 27MHZ receiver and expect it to work.

Really Ken? I've found the crystals from the old (black) rxs and new (blue) rxs are compatable? For example, I had my SSE on a blue rx with a 49 when crystal. When it died (RIP) I switched the crystal to an old (black) rx to use in my profile plane. Will this really cause a problem, we have so many old/new rxs that swapping crystals has become common place at my house.

TheParrot,
I was basing that on my LHS. When I ordered crystals for my Airtronics stuff he asked me which I had and said that it mattered. Now that I have gone and looked at it myself I see that the crystals are the same for both old and new. I will stand corrected.

Ken

No problem, was just clarifying, wanted to make sure I didn't have a bunch of crashes waiting to happen.

Ch 5 is actually in the 50MHz band reserved for those with amateur licenses. You should not transmit on that freq unless you have an amatuer license. I realize we are talking about recievers. Simply installing a Ch 18 crystal will not work. They are on imcompatable bands and will need rework by a shop at the very least.

Cheaper to buy a new reciever (and crystal) for this project.
From AMA site:

Amateur Radio Operator License Required for 6 Meters
(Technician, General, Advanced, Extra class)
(Other Amateur Radio Service [ARS] frequencies may be
used, as regulated by the FCC)

We all have those, but at least yours won't be due to crystals!

Somehow I knew when I saw Chuck posted on this thread that he'd say something like that!

when i said channel 5 I was just using it as an example but if you say the 72mhz start at 11 well my reciever will be between 11 and 33, so i'm sorry for any confusing.