coops1

I have a multiplex pico receiver and cant get it to work with my futaba challenger transmitter. I have lost the transmitter crystal and have been using futaba ones and they don't seem to work with the multiplex receiver ( it does say on the receiver use multiplex crystals only) but all i need to know is if i buy a new pair of multiplex crystals (or the transmitter one which is missing) will they work with the futaba handset?
or will i need to buy an new receiver which is compatible with futaba xtals.
cheers

dirtybird

My Feedback: (5)

In the US the Multiplex receivers have to be modified to work with Futaba transmitters. The shift direction is wrong.
I don't know about where you live. The equipment supplied for your area may be different.

coops1

I used to use the receiver with my mates futaba skysport handset but his handset broke and got thrown away with the transmitter crystal so it did work just wondered if anyone knows whether i need to get the same number on the xtal ie the number on the chip is ko62E on the top, mpx-fm 34,565 on one side and Eo62 on the other. So would a multiplex xtal with 62 work or does the other numbers need to match aswell?

olivier

Hi,
If the crystal mentions 34.565, with Multiplex you have to add 455kHz, which gives you :
34565+455=35.020Mhz
You also mention the figure 62 which would be channel 62, so check with this link for example :
http://www.rc-network.de/magazin/art...aender/BEL.pdf
and you will find that channel 62 is indeed 35.020Mhz.
In the 35Mhz-band, all recent (>1980) receivers in PPM (not PCM) are compatible with other brands of transmitters, if both in FM (not AM), there is NOT such a thing as negative or positive shift in the 35Mhz fortunately.
So what you need is :
1) a 35.020Mhz-transmitter-crystal of the same brand as your transmitter in your transmitter
2) a 35.020Mhz-receiver-crystal of the same brand as your receiver in your receiver (if it's a dual-conversion receiver, you'll need a "dual"-cristal).
3) or any other pair of crystal in the 35Mhz-band with the same specs as mentionend in point 1 and 2 here above

Hope this is all clear, if not, revert.

Olivier

coops1

yeah that does make sense. I know it used to work, not with my current tx, but my mates old futaba skysport 6. I don't have the crystal for it anymore, i still have the one i mentioned for the rx and just want to know if i buy a new crystal with the same number will it work? You say that the positive shift thing does not apply with 35mhz does this mean the crystal which i need to buy to match the one in my rx will work in the futaba handset?