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dots on crystals

Old 06-29-2002, 05:33 PM
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Default dots on crystals

What the heck are the three dots on the crystals. Are they all compatable if they are the same freq.

Ron - AMA 1025
Old 07-01-2002, 11:56 AM
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Default dots on crystals

Ron,
The dots on the crystal indicate how the crystal is tuned. A center dot indicates the crystal tuned right on the frequency, and left or right indicates that it tuned slightly off the exact center of the frequency on a scope. With the level of tuning today, it doesn't mean much. It used to be a guideline to not use a set of crystals with opposite dots, but it doesn't mean much today.
Thanks!
Danny
Old 07-01-2002, 01:02 PM
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Default crystals and rx

Do you mean hoe the crystal is tuned or how the receiver is tuned. IS it true that rx's are tuned for high and low band or does that matter. If so, then why can you use the Hitec rx on all 50 freq.

Ron - AMA 1025
Old 07-01-2002, 01:08 PM
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Default dots on crystals

Ron,
Old 07-01-2002, 01:11 PM
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Default dots on crystals

Ron,
It is how the crystal is tuned, and does not indicate anything about the receiver. Receivers used to be tuned, JR at least, by a high and low band. But this is not the case any longer.
Sorry about the previous message, I hit the wrong key and it sent a reply...
Thanks!
Danny
Old 07-05-2002, 07:01 AM
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Default dots on crystals

Actually, it is how the crystal is cut, not tuned.

But as Danny said, with modern design and tuning, the dots don't matter anymore.
Old 07-06-2002, 04:22 AM
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Default dots on crystals

Danny:

FYI You could have editted that message and saved creating a new one. Just FYI.
Old 07-07-2002, 12:56 PM
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Default dots on crystals

It is tolerance limits . High ,center or lower limit . It is how the crystals are GROUND . The pressure in the mounting can also affect the crystals frequency.
In an ideal situation the transmitter and receiver would have matching crystals. Although we call them NARROW BAND radios ,they are not so narrow that the difference we are talking about is any concern.

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