Are there any sources for crystals for FMA recivers besides FMA? Looking for a ch 42 crystal. THanks.
- posted
19 years ago
Are there any sources for crystals for FMA recivers besides FMA? Looking for a ch 42 crystal. THanks.
| Are there any sources for crystals for FMA recivers besides FMA? | Looking for a ch 42 crystal. THanks.
Radical RC.
Also, if you have a FMA receiver crystal for another channel, Radical RC will exchange it for $5.
I got a question about crystals.. just what is the difference between a say, a JR channel 42 and a FMA channel 42? Is it just a physical difference or ?
| I got a question about crystals.. just what is the difference | between a say, a JR channel 42 and a FMA channel 42? Is it just a | physical difference or ?
It's hard to say. They might be the same, or they might not. It depends on how the receiver is built.
Most JR receivers are single conversion, where most of the FMA ones are dual conversion. That alone will almost certainly mean that the crystals will have different values.
For the most part, the crystals are identical except for the value -- but the values for different brands (or even models) can be quite different, even though they're meant to receive the same channel.
Better just get a FMA crystal. Perhaps another crystal will work, but even so, it's possible that it'll work but with issues -- it's not worth the risk.
Things that CAN be different.
(i) Frequency. It can be single or dual, and cut for above, or below the incoming differeing of course by teh IF used. So thats 4 potential basic frequencies all marked 'channel X receiver'
(ii) Overtone. It might be cut to work at teh fundamental, 3rd or 5th overtone. If cut for a different setup to what it finds, it may not ocsilate, or weakley.
(iii) capacitative and other loading. Crystals are quite happy to ocsillate some way off the 'marked' frequency if loaded with capacitors. Its probavbly possiibe to 'pull' one at leats a channel off band....
Answer? They might be identical. They might not work at all. They might be half a channel out.
Wanna risk it?
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