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new JR Crystal does not work, why?

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Old 05-29-2003, 01:15 AM
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FlooredCOBRA
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Default new JR Crystal does not work, why?

I am running JR radio servos and receivers. I just ordered some new crystals to install into some of the other receivers. For some reason they don't work.

The frequency I am on is 72.570 and the new crystals I ordered are the same numbers. But one thing I can see that is different is they are in a red case instead of grey. Also they have a gold label on them and it says FM Rx DC 72.570. The other set of crystals do not say DC on them and also on the 3 dots the last dot is black. On this new set I have the second dot is black.

The pack they came in says (JRPXDR) FM/ PCM Dual Conversion Crystal. What in the world does this mean? Is there something I need to do to get them to work or are these the wrong ones?

Also the radio I am using is the JR X783.

Any thoughts?
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Old 05-29-2003, 01:34 AM
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MikeL
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Default new JR Crystal does not work, why?

Most JR receivers in the US are single conversion. Which model receiver are you trying to use your dual conversion crystals in?
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Old 05-29-2003, 01:36 AM
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Default new JR Crystal does not work, why?

Dual conversion and single conversion crystals are not interchangable are your Rx's single conversion? I am not a JR user and not familiar with JR markings but suspect this is your problem.

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Old 05-29-2003, 01:38 AM
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FlooredCOBRA
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Default new JR Crystal does not work, why?

I have 2 types . One is a 549X and the others are NER 327X
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Old 05-29-2003, 01:41 AM
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FlooredCOBRA
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Default new JR Crystal does not work, why?

i guess they are single, I am not to sure. When I ordered them all I said was I needed a 72.570 RX crystal. I didn't know they had duals or singles.

One thing though why does it say Dual Conversion if it can not be converted back to single?

Does not sound to Conversion to me.
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Old 05-29-2003, 03:07 AM
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nitroman88
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Default new JR Crystal does not work, why?

Dual conversion rec are different from Single conversion rec. You probably ordered the DC crystals instead of the SC crystals. you cannot use DC crystals with SC receivers
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Old 05-29-2003, 07:48 AM
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Steve Lewin
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Default new JR Crystal does not work, why?

Only the top-end JR receiver is dual conversion, all the others are single conversion. You just got the wrong crystals.

BTW dual conversion refers to frequency conversions inside the receiver. There are 2 of them .

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Old 05-29-2003, 03:20 PM
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Default new JR Crystal does not work, why?

The word conversion in dual / single conversion refers to the method by which the RF frequency is derived from the crystal's resonance frequency.

Long story short, single conversion (SC) Rx requires SC crystal, dual conversion (DC) Rx needs DC crystal.
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Old 05-29-2003, 07:35 PM
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Default new JR Crystal does not work, why?

thanks guys.

I called the hobby shop and they got some singles on the way. Luckily I can take these back and swap them when they come in.
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