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Must receiver freq. equal crystal freq?

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Old 08-11-2003, 07:55 PM
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Martin V
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Default Must receiver freq. equal crystal freq?

I just purchased a 8 channel hitec superslim dual conversion receiver. My trasmiter is CH 27 so I reqested a CH 27 crystal which I got, but the receiver says CH21, 72.210 on the side. Isn't the receiver supposted to be whatever frequency the crystal is? Will this combination work? If so will the range be the same.
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Old 08-11-2003, 08:18 PM
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Default Must receiver freq. equal crystal freq?

If the tx is on ch 27 and they sent you a ch 21 crystal for the rx...you won't have to worry about range problems...IT WILL NOT WORK at all !!!
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Old 08-11-2003, 08:19 PM
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Default Must receiver freq. equal crystal freq?

No, it will not work. The CH#, or more specifically the frequency must match in the TX and RX for them to communicate. CH27 is 72.330MHz and CH21 is 72.210MHz. The channel #'s really don't match the frequency fractions. CH21 is a fluke. The channels just make it easy for people to remember... lot easier to remember CH27 than 72.330 MHz. For a full listing of how the channel #'s are assigned to frequencies, check here.

http://www.advancedrc.com/freq.html

Cheers
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Old 08-11-2003, 09:43 PM
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Default Must receiver freq. equal crystal freq?

if the rx crystal they sent you is in fact the one you requested, but the rx has a sticker that says something else, it'll work fine. it's exactly the same as if you change the crystal in a rx you already have. the rx might say 21, but the crystal is what makes the freq.
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Old 08-12-2003, 03:19 AM
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Default Must receiver freq. equal crystal freq?

THe sticker on the RX unit is for whatever crystal it came with. If it was a 21 and you put a 27 in it. The RX is now on Channel 27.

People should read his problem better before answering Except for Stick.
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Old 08-12-2003, 06:04 AM
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Martin V
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Default Must receiver freq. equal crystal freq?

Thanks, that is what I was hoping for.
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Old 08-12-2003, 06:33 AM
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Default Must receiver freq. equal crystal freq?

Boy, I understand now, but even after I re-read the initial post about ten times, it's still not real clear to me what was going on. Regardless, my apologies for a misguided post. Better to post too much info and be clear as to your question than not enough. Somehow I was convinced you had a CH21 x-tal in the RX.

As for range, 21 vs 27 is close enough I'd think you wouldn't need to retune. Range may be off slightly, say a percent or so... nowhere close to enough to worry about.

On a side note, yank that CH21 sticker off the RX. Probably not a real biggie with the RX, but I recently saw a mislabeled TX shoot down a very nice plane. No good reason to leave the wrong sticker on the RX.
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