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Crystal switch?

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Old 07-14-2004, 03:40 PM
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SVX
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Default Crystal switch?

I bought a new Futaba Radio, the t6xa (the older computer radio). It is the PCM version. The channel it came with is already being used at our field so I wanted to switch transmitter crystals with my old Skysport Futaba FM radio. the switch worked, my old cub responded when I switched the new radio to PPM. My question is the new radio (servo's and receiver) is in my At-6 which again is PCM, if I buy a new PCM crystal for the new receiver and switch the transmitter to PCM will it work? The old crystal I put into the new transmitter was an FM so I worry that it won't work with the new PCM receiver however, the new crystal I pulled out of the new transmitter was also an FM. Will this work? More importantly does my question make sense?

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Old 07-14-2004, 04:00 PM
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Default RE: Crystal switch?

Crystals don't care if you are using PPM or PCM modulation, so you don't have to worry about that. There are a couple things you do need to take into consideration:

1.) It violates FCC rules to change the crystal in your transmitter (I'm not the frequency police, I just thought you might like to know). You can change your receiver crystal at any time. Since you fly Futaba make sure you use a crystal in the same band as your receiver (ch. 11-35 is low band, 36-60 is high band) and be sure it is dual conversion if the receiver is a dual conversion receiver.

2.) If I'm not mistaken, the transmitter is tuned to a specifical frequency (channel), so when you swap transmitter crystals you actually throw the transmitter out of tune. Now, you can change a transmitters frequency, but it needs to be done by a certified technician.

My suggestion to you is put your transmitters up for sale on the RCU Marketplace or Ebay or sell them to a friend and buy a transmitter with a frequency module (cartridge). The module contains all the stuff needed for a particular channel. You can then buy different modules to fly on different channels. For instance, I have a Futaba 9c with a ch. 19 and a ch. 35 frequency module. I have a few planes on ch. 19 and a couple more on ch. 35. When I go from plane to plane, I pop out one module and replace it with the other.

I hope this helps a bit.
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Old 07-14-2004, 07:42 PM
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Default RE: Crystal switch?

Great[] sounds like I will be paying out more $$$ to Futaba. Thanks for the heads up, I thought about the 9C but can'r really afford it right now. Thanks for the info, SVX
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Old 07-15-2004, 09:47 PM
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Default RE: Crystal switch?

Futaba did offer a synth module like Hitec at one time. Of course the Hitec will work in the Futaba, but we would want to do anything illegal now would we?
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