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Want to Hack a Frsky backwards to 72Mhz

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Old 09-27-2018, 08:01 PM
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kinkele
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Default Want to Hack a Frsky backwards to 72Mhz

Hi Guys.
This is a strange endeavour. I run RC Submarines. 2.4G wont penetrate water, 433Mhz kind of does, I use 75 or 72Mhz, I would love 35 or 40Mhz. The lower the better.
But I want a new radio for the future. I want a FrSky Taranis Q X7, open source. I understand it uses a JR Standard Module size. Can I get a JR 72Mhz Synthesised Module, add an antenna and use it in the Frsky?

For a while people were hacking 2.4g modules into 72Mhz radios, I just want to do the reverse, hack a 72Mhz module into a 2.4g radio.

Thanks
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Old 09-28-2018, 05:18 AM
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AndyKunz
 
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You need to be using 75MHz or 27MHz in the USA for a surface model (or sub-surface ). 35 and 40 are not legal frequencies for model use here.

If you can find a JR 75MHz module, that is what you want. You will need to make some modifications to the radio to connect to the antenna output. Find yourself a licensed Ham operator (start at Home ) and you'll be much better off. Legal, too.

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Old 09-28-2018, 09:47 AM
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While the JR module would probably prove to be the easiest, any RF deck or module on 75 should be able to work.

I'd start by contacting Radio South and see what Tony has to say. Since he does conversions from 72/75 to 2.4, he might have the modules or decks on hand. I'm sure he'd even be able to perform the conversion for you.
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Old 10-05-2018, 09:31 AM
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Thinking some more about this, I don't know what other features your FrSky Taranis Q X7 has that goes through the signal. But a lower frequency means a lower data rate. And depending on things it is possible you might end up with slow updates on the Rx which could lead to slow or jerky control response. Just a thought.
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Old 10-05-2018, 09:42 AM
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Effective data rate of most 2.4gHz RF systems is about 9600 baud - the same as we had on 27/72/75.

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