Volante24

Let me put my 5 cents, since I was trying to save (little) money (and get fun) using similar tricks. First, crystals for dual and single conversions receivers are on totally different frequencies -- they differ by about 10MHz (of 60)! With the receiver crystals nowadays, the frequency marked on them is NOT the frequency this crystal oscillates, but what frequency the receiver will accept with this crystal plugged in.

Now, Futaba and Hitec RX crystals for the same channel DIFFER in the frequency they generate. I found it experimentally using just an ICOM scanner I had. If I recall correctly, the difference was 10kHz -- just half the distance between the channels. So, if you plug Futaba crystal, say for channel 20 into a Hitec receiver (I did this with a dual conversion receiver), you would get the receiver operating on "channel 20-1/2" (or "19-1/2" , do not remember details). If you plug the Hitec crystal in a Futaba receiver, you also get half a channel off, but in the opposite direction.

Since there are no RC transmitters for half-integer channels in the US, this conclusion is difficult to check, but I am ready to bet is is like that.

Crazy? -- I think so. Probably, this roots to the different (second) IF employed by Hitec vs. Furaba. Probably one uses 450 kHz, and another 460kHz -- hence the heterodyne (which utilizes the crystal you plug) has to be on the frequencies differing by the same 10 kHz, to receive the same radio signal.

Unfortunately, the Hitec guy did not respond to my e-mail asking what is the second IF in their receivers, although usually they respond quickly.

Hope this helps. The summary: RX crystals can be different, in one thing -- just their own frequency for a given channel. (Don't be tricked by the ferquency number written on the RX crystals). GWS and Futaba seem to be the same, Hitec differs by 10kHz. I don't know about others.

Nick