Keat Posted August 2, 2009 Share Posted August 2, 2009 Folks. My latest model (used low wing trainer) came with a Sanwa TX & Rx setup. However, I'd much prefer to use one of my Futaba TX's. Can I use the crystal from the Sanwa TX in a Futaba TX, or similarly use a Futaba Crystal in the Sanwa RX ? Quote Link to comment Share on other sites More sharing options...
Keat Posted August 2, 2009 Author Share Posted August 2, 2009 I think I've just answered my own question. The Futaba TX would not transmit either in PPM or PCM mode with the Sanwa Crystal, or if it did, the model had no response But switch for a Futaba Crystal in the TX and another futaba crystal in the Sanwa RX, and the combination seems to work. I guess I just now need to do some ground safety and range checks. Quote Link to comment Share on other sites More sharing options...
John Privett Posted August 2, 2009 Share Posted August 2, 2009 You should use the make of crystal that matches what you're plugging it into. So use a Futaba Tx crystal in the Futaba Tx, and a SANWA Rx crystal in the Sanwa Rx. Other combinations might appear to work, but will probably have decreased range. As long as you're using PPM, the Sanwa Rx doesn't know whether it's "listening" to a Sanwa Tx, a Futaba Tx, a JR Tx or indeed any other Tx. Quote Link to comment Share on other sites More sharing options...
Keat Posted August 2, 2009 Author Share Posted August 2, 2009 maybe i'll look at buying another futaba crystal for th tx then. thanks for the info. Quote Link to comment Share on other sites More sharing options...
John Horsfield Posted August 2, 2009 Share Posted August 2, 2009 I agree with John, be careful when using other branded crystals in Sanwa stuff. (The TX will defiantly need a Sanwa crystal). Quote Link to comment Share on other sites More sharing options...
John Privett Posted August 2, 2009 Share Posted August 2, 2009 Posted by John Horsfield on 02/08/2009 22:08:37:I agree with John, be careful when using other branded crystals in Sanwa stuff. (The TX will defiantly need a Sanwa crystal). Just to clarify what I hope John H meant... If you use the Sanwa Tx then it will need a Sanwa Tx crystal. If you use your Futaba Tx then it will need a Futaba Tx crystal. Regardless of which Tx you use the Sanwa Rx will need a Sanwa Rx crystal. Quote Link to comment Share on other sites More sharing options...
Keat Posted August 3, 2009 Author Share Posted August 3, 2009 I intend to use my Futaba TX's, so Iv'e ordered a Futaba 82 TX crystal today. The Sanwa stuff came with 82 installed already, so I'll put the 82 Sanwa Crystal back in the Sanwa RX. I might sell the Sanwa TX on Fleabay.. if nothing else, it will pay for the Futaba Crystal I guess. Shame, as it feels lile a well made, if not very basic, piece of kit. I just don't have a requirement for 3 TX's. Quote Link to comment Share on other sites More sharing options...
Erfolg Posted August 3, 2009 Share Posted August 3, 2009 The sanwa receiver should work a futaba Tx should it not? If each has its own make of crystal. The basis for this statement is the thought, for sake of argument, you transitting on 70, the output signal should be that wave length and that specific wavelength is what the receiver should be processing. I also understood that the PWM had been standardised on all sets? These are questions, not answers. Erfolg Quote Link to comment Share on other sites More sharing options...
John Privett Posted August 3, 2009 Share Posted August 3, 2009 Posted by Keat on 03/08/2009 14:52:02:I intend to use my Futaba TX's, so Iv'e ordered a Futaba 82 TX crystal today. The Sanwa stuff came with 82 installed already, so I'll put the 82 Sanwa Crystal back in the Sanwa RX. Yes, that should be fine. Posted by Erfolg on 03/08/2009 15:03:05:The sanwa receiver should work a futaba Tx should it not? If each has its own make of crystal. The basis for this statement is the thought, for sake of argument, you transitting on 70, the output signal should be that wave length and that specific wavelength is what the receiver should be processing. I also understood that the PWM had been standardised on all sets? These are questions, not answers. ErfolgErfolg, you are correct. As long as you're using PPM rather than PCM then anything you're likely to encounter on 35MHz should work together. The only incompatibility I can think of is that the wiring of old Sanwa servo plugs differs from the "standard" used by everybody else, and indeed by Sanwa for the last (I'm guessing here...) 10 or 15 years? Edited By John Privett on 03/08/2009 17:08:22 Quote Link to comment Share on other sites More sharing options...
BB Posted August 3, 2009 Share Posted August 3, 2009 You can use any xtal of the same frequency. But, it is not recomemended. PPM ok PCM, not so. "Check before tryin'. BB Quote Link to comment Share on other sites More sharing options...
John Privett Posted August 3, 2009 Share Posted August 3, 2009 Posted by Basildon Biggles on 03/08/2009 17:39:36:You can use any xtal of the same frequency. But, it is not recomemended. PPM ok PCM, not so. "Check before tryin'. BB It's been stated many times elsewhere that there is more to a crystal than simply its frequency and differences for instance in its capacitance can cause a transmitter with an "alien" crystal to output a signal on a different frequency to the one intended. I've only tried this once - and it failed. A transmitter crystal from a GWS radio was tried in an old Futaba FF6 (we wanted to buddy-box it with the GWS Tx) and with this combination the GWS receiver failed to respond. A check with a radio scanner showed the Futaba transmitter was now transmitting on a frequency between the intended one and the adjacent channel - but closer to the adjacent one. Fortunately this was tried at home and not at the field where the result could have been a shot-down model... Subsequently a Futaba Tx crystal on the relevant channel was acquired and the GWS receiver then responded to the Futaba Tx and we were able to buddy-box the two successfully. Quote Link to comment Share on other sites More sharing options...
Former Member Posted August 3, 2009 Share Posted August 3, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Glyn R Posted August 3, 2009 Share Posted August 3, 2009 What is the issue here? Only use a crystal of the same make as the box you plug it into. No other rule is safe. You can try all you like but you will never know until it goes wrong. Quote Link to comment Share on other sites More sharing options...
BB Posted August 3, 2009 Share Posted August 3, 2009 Posted by John Privett on 03/08/2009 18:59:28: Posted by Basildon Biggles on 03/08/2009 17:39:36: You can use any xtal of the same frequency. But, it is not recomemended. PPM ok PCM, not so. "Check before tryin'. BB It's been stated many times elsewhere that there is more to a crystal than simply its frequency and differences for instance in its capacitance can cause a transmitter with an "alien" crystal to output a signal on a different frequency to the one intended. I've only tried this once - and it failed. A transmitter crystal from a GWS radio was tried in an old Futaba FF6 (we wanted to buddy-box it with the GWS Tx) and with this combination the GWS receiver failed to respond. A check with a radio scanner showed the Futaba transmitter was now transmitting on a frequency between the intended one and the adjacent channel - but closer to the adjacent one. Fortunately this was tried at home and not at the field where the result could have been a shot-down model... Subsequently a Futaba Tx crystal on the relevant channel was acquired and the GWS receiver then responded to the Futaba Tx and we were able to buddy-box the two successfully. Gotta be careful here. In a previous post the question asked was along these lines (not verbatim). Can I used the same Xtals in a 35Mhz set with the tx and rx of different makes. My answer was yes. However, some replies stated that, if you had (for aurguments sake) a Futuba tx and and sanyo Rx you could use the Sanyo Xtals in the rx & tx. Others said NO, Futaba for tx & Sanyo for rx. All knowledge aside... They are that cheap, buy a set and try them. Low power close, antenna down/ full throttle far, antenna down & extended. Range check . BBEdited By Basildon Biggles on 03/08/2009 21:11:06 Quote Link to comment Share on other sites More sharing options...
BB Posted August 3, 2009 Share Posted August 3, 2009 Beyond that, it would make sense if both 'master' & 'buddy' box (tx) were carrying the same Xtals, even if the rx was of a compatable, though different make. A full control test will eliviate any worries. BB Quote Link to comment Share on other sites More sharing options...
Former Member Posted August 3, 2009 Share Posted August 3, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Keat Posted August 3, 2009 Author Share Posted August 3, 2009 Blimey. I opened a preverbial can of worms here. I didn't realise that it would make that much difference, and was going to take the TX on a drive to see how far the range would have been. However, having taken John Privetts advice, i'm going to TEST the following combination. Futaba TX with Futaba 82 crystal. Sanwa RX with 82 Sanwa crystal. As for Phil Wood's post about CB alpha channels......... ooops. Nuff said. Quote Link to comment Share on other sites More sharing options...
Former Member Posted August 3, 2009 Share Posted August 3, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
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