Diamond Geezer Posted August 26, 2008 Share Posted August 26, 2008 hi guysneed some help posted this in radio forum no reply how do you identify 35 meg xrystals if the label is missinggeoff Quote Link to comment Share on other sites More sharing options...
birdy Posted August 26, 2008 Share Posted August 26, 2008 You could put it in the tx and use a frequency checker. Quote Link to comment Share on other sites More sharing options...
Diamond Geezer Posted August 26, 2008 Author Share Posted August 26, 2008 cheers birdie but i dont have 1 Quote Link to comment Share on other sites More sharing options...
Brian Parker Posted August 26, 2008 Share Posted August 26, 2008 Unfortunately you need access to a frequency counter or a digital ‘scope and need the casings removed for access, also you will need to know whether the crystals are RX or TX and if TX, the manufacturer. Also you will need a crystal of known frequency for reference in case of any offset. Or you could use trial and error! Quote Link to comment Share on other sites More sharing options...
Former Member Posted August 27, 2008 Share Posted August 27, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Brian Parker Posted August 27, 2008 Share Posted August 27, 2008 A crystal without a label is no more unsafe than one with a label. If the wrong crystal is fitted the receiver will not respond! If a crystal is damaged it will fail to resonate and again the receiver will not respond.Crystals (also equipment utilising crystals) are relatively easy to damage through shock. Treat them like eggs! Quote Link to comment Share on other sites More sharing options...
Former Member Posted August 27, 2008 Share Posted August 27, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Brian Parker Posted August 27, 2008 Share Posted August 27, 2008 Yes, I take your point, but only if one is daft enough to do the testing with the receiver in a model and in the vicinity of a flight line. Quote Link to comment Share on other sites More sharing options...
Former Member Posted August 28, 2008 Share Posted August 28, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Brian Parker Posted August 28, 2008 Share Posted August 28, 2008 Eric,Would it transmit ‘out of band’ if an incorrect non-fundamental crystal was fitted taking into account the fact that the oscillator itself will be tuned to the overtone or the harmonic (depending on type design)? Any output surely will be so attenuated as to be virtually non-existent. Quote Link to comment Share on other sites More sharing options...
Former Member Posted August 29, 2008 Share Posted August 29, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
birdy Posted August 29, 2008 Share Posted August 29, 2008 I only got the Eric Bray wrote (see)Most people won't have a clue what we are talking about! bit. Quote Link to comment Share on other sites More sharing options...
Brian Parker Posted August 29, 2008 Share Posted August 29, 2008 Eric,This thread wouldn’t exist if the resonate frequency was stamped on the crystal’s casing during manufacture. Makes one assume that they are tested for resonance after manufacture (to a wide tolerance) and a sticky label with the nearest frequency appropriate to a 35Mhz channel is then attached. Quote Link to comment Share on other sites More sharing options...
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