'Widget' Posted November 16, 2008 Share Posted November 16, 2008 Can any one tell me how to identify the xtal channel number by the numbers on the xtal's themselvs, for instance my RX xtal reads 35mhz FM 36.060. How can I tell what the channel number is and what imformation would be on the Tx xtal ? Quote Link to comment Share on other sites More sharing options...
Brian Lambert Posted November 16, 2008 Share Posted November 16, 2008 Well.... assuming a receiver IF of 455Khz that would probably be channel 75.Brian Quote Link to comment Share on other sites More sharing options...
'Widget' Posted November 16, 2008 Author Share Posted November 16, 2008 Thanks Brian, but could explain the 'break down' of the result please. Quote Link to comment Share on other sites More sharing options...
Graham Bloice Posted November 16, 2008 Share Posted November 16, 2008 Rusper wrote (see)Well.... assuming a receiver IF of 455Khz that would probably be channel 75.Brian Are you sure? A little bit of Google fu turned up several links such as the UK Radio Control Council HERE which show that there is no airborne 35MHz channel for 36.060MHz. In addition I believe the I/F frequency of the receiver does have an effect on the actual crystal frequncy required, but most (all?) RC crystals I have seen marked with a frequency show the eventual 35MHz frequency.Channel 66 is on 35.060 MHz, maybe the OP mis-read or mis-typed it. Graham Quote Link to comment Share on other sites More sharing options...
Former Member Posted November 16, 2008 Share Posted November 16, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Brian Lambert Posted November 17, 2008 Share Posted November 17, 2008 Graham Bloice wrote (see)Rusper wrote (see)Well.... assuming a receiver IF of 455Khz that would probably be channel 75.Brian Are you sure? No! more later. Graham Brian Quote Link to comment Share on other sites More sharing options...
Alan Dunstan Posted November 17, 2008 Share Posted November 17, 2008 Eric is not quite right. UK frequencies as given in the BMFA handbook page 67 go from Chn 55 @ 34.950Mhz to Chn 90 @ 35.300Mhz. The handbook also gives the way to work out the channel number from the frequency (copied directly from the manual.)To Identify the Channel Number of an Untagged Crystal,(1) If the crystal is marked 34.xxx you subtract 40 from the first two numbers after the decimal point of the frequency marking, (i.e. 34.960, subtract 40 from 96 giving channel 56) (2) If the crystal is marked 35.xxx you add 60 to the first two numbers after the decimal point of the frequency marking, (i.e. 35.260, add 60 to 26 giving channel 86).However Eric is very right that the frequency given at the start of this thread, eg 36.060Mhz is not legal for RC Model aircraft in the UK and should not be used.Hope this clears things up. The BMFA handbook is a goldmine of info on these things. Definitely worth reading (must do so myself more often).Alan Quote Link to comment Share on other sites More sharing options...
Former Member Posted November 17, 2008 Share Posted November 17, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Alan Dunstan Posted November 17, 2008 Share Posted November 17, 2008 Eric - I read it straight off the BMFA website. A fountain of knowledge for stuff like this. It downloads straight into a pdf file. The extra frequencies (50 to 54 & 86 to 90) were added around 4 years ago I seem to remember. Must admit I never knew about the way to identify the channel number before reading this today.Alan Quote Link to comment Share on other sites More sharing options...
Brian Lambert Posted November 17, 2008 Share Posted November 17, 2008 Right now I have slept please ignore everything I said yesterday. Could we have a picture of the Xtal with the markings? Is there any possibility that it came from Australia where it could have been channel 606?Brian Quote Link to comment Share on other sites More sharing options...
Ben Mullins Posted November 17, 2008 Share Posted November 17, 2008 Dont know if this helps, but 35.150 is channel 75, its what I fly on! Quote Link to comment Share on other sites More sharing options...
'Widget' Posted November 17, 2008 Author Share Posted November 17, 2008 Sorry chaps, the 'mark one's' are not what they used to be !! Rx Xtal reads 35.060, so does it make them channel 66 ? Quote Link to comment Share on other sites More sharing options...
Brian Parker Posted November 17, 2008 Share Posted November 17, 2008 ChannelFrequency ChannelFrequency6035.000 5534.9506135.010 5634.9606235.020 5734.9706335.030 5834.9806435.040 5934.9906535.050 6635.060 6735.070 6835.080 6935.090 7035.100 7135.110 8135.2107235.120 8235.2207335.130 8335.2307435.140 8435.2407535.150 8535.2507635.160 8635.2607735.170 8735.2707835.180 8835.2807935.190 8935.2908035.200 9035.300 Quote Link to comment Share on other sites More sharing options...
Brian Parker Posted November 17, 2008 Share Posted November 17, 2008 Don't know what has happened to the last post but tried to post a spreadsheet of frequency/channels and it didn't post correctly. Quote Link to comment Share on other sites More sharing options...
Brian Lambert Posted November 17, 2008 Share Posted November 17, 2008 Yes Chanel 66 see Here Quote Link to comment Share on other sites More sharing options...
Former Member Posted November 18, 2008 Share Posted November 18, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Brian Lambert Posted November 18, 2008 Share Posted November 18, 2008 Oh Eric you'r so picky Quote Link to comment Share on other sites More sharing options...
'Widget' Posted November 18, 2008 Author Share Posted November 18, 2008 Thank you all for your help on this one. Quote Link to comment Share on other sites More sharing options...
arko66 Posted November 29, 2008 Share Posted November 29, 2008 I have taken the advice of this forum and joined a club. Myself and my son have been allocated our own channels, 79 and 81. I didnt want to look daft and so I didnt ask the club admin about how to get hold of or how to recognise the crystals for these channels. So if anyone can throw some light on this for me I would be very grateful. We both have 35 mhz transmitters. Quote Link to comment Share on other sites More sharing options...
Brian Lambert Posted November 29, 2008 Share Posted November 29, 2008 Ian, the crystals you want will have the channel number on them , any crystals that have been treated so badly that they have lost their identification should be viewed with suspicion. I would get me a set of crystals from the manufacturer of the radio gear. Transmitter crystals are not necessarily interchangeable between makes and receiver crystals are a mine field. My advice get the correct ones for your equipment.I hope that is of some help Brian Quote Link to comment Share on other sites More sharing options...
arko66 Posted November 29, 2008 Share Posted November 29, 2008 Thanks Rusper. I have just been searching but to no avail. Im not sure what Dual Conversion means as this appears quite a lot around the various websites. I have a Graupner Tx and my son has a Carson Eagle Tx. Could anyone also supply some web sites where I might be able to find the crystals I need? Thanks. Quote Link to comment Share on other sites More sharing options...
Brian Lambert Posted November 29, 2008 Share Posted November 29, 2008 Ian, Dual conversion is a technical bit of how some receivers work but I think you only need to know that the crystals are not the same for single and dual conversion receivers.Brian Quote Link to comment Share on other sites More sharing options...
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