View Full Version : iwaver 27mhz FM crystal question?

2007.11.08, 01:12 PM
Hi fangle

I used the 07 crystal set i got from toyeast on my stock kyosho 27mhz AM TX and RX and it worked. I was able to control the miniz with the iwaver 07 27mhz FM crystals. Now the miniz TX is AM and the RX is AM, why is this working? is the iwaver crystal really FM? I know they can cause interference but to run an AM system with FM crystal set thats wierd. Please explain.

Thank you

2007.11.08, 03:32 PM
The crystal you insert into the radio only provides a base signal at some specific frequency near 27 megahertz. The radio then adds "information" onto the signal using frequency modulation (FM) or amplitude modulation (AM) before transmitting. The same crystal can be used in either type of radio.

AM and FM radios running at the same frequency will interfere with eachother because any receiver out there tuned to that frequency will receive a combination/mixture of the two signals.

Simple analogy:
Ever tuned your stereo in between two radio station frequencies and started hearing a mix of the two different broadcasts? It is kind of hard to understand either radio signal because they overlap - the same is true for your mini-z.

2007.11.08, 07:03 PM
Hi kja812

Thanks for the info. You made it very simple.


2007.11.11, 08:22 PM
hum...that is the reason behind the interference between the AM and FM 27Mhz.
I'll talk this over with the electrical engineer and see if they could write the "information" differently in order to minimized the frequency interference issue.

2008.06.15, 10:48 PM
So does this mean you can run a 27mhz fm radio with the mini z in othere words if i bought a 27mhz fm radio and put the crystal 27mhz fm in the car to match my 27mhz fm radio would that work?

2008.06.16, 12:06 AM
I can't confirm the following, but here is my 2 cents of what I know.
AM and FM runs in the same frequency, the only difference between them is the signals.
The "information" is written and transmitted in differently for the two channel.
So there is a chance that AM or FM to be mixed with each other causing interference.
As far as I know, one of the crystal from the pair (TX or RX) is actually the same between AM and FM. However you would not be able to control it perfectly using the wrong channel.