Chris Procter Posted January 29, 2012 Share Posted January 29, 2012 Hi all, Firstly I've used the search function which asks similar questions to mine but doesn't provide a definite "yes" So, my instructor is using a spektrum transmitter which won't buddy with my Futaba T7C 2.4g, so before I go ahead and buy a used box to use as a buddy, which ones will actually work? Which setup has worked for you? I'm hoping not to have to shell out on another T7C but maybe a used 6ex ? Many thanks Chris Quote Link to comment Share on other sites More sharing options...
Stephen Grigg Posted January 29, 2012 Share Posted January 29, 2012 I think youll find a Futaba works with a Futaba and a spectrum works with a spectrum as long as both sets are 2.4 or 35mh Quote Link to comment Share on other sites More sharing options...
Chris Procter Posted January 29, 2012 Author Share Posted January 29, 2012 Thanks Stephen, I'm hoping to get hold of a 2.4g 6ex to use as a trainer box rather than another T7C, they're slightly cheaper used and wanted to make sure they're compatible. Cheers Chris Quote Link to comment Share on other sites More sharing options...
Codename-John Posted January 29, 2012 Share Posted January 29, 2012 I think you can use almost any modernish futaba tx, you can use 2.4 to 35 with futaba also as its not transmitting a signal from the buddied tx only the master Quote Link to comment Share on other sites More sharing options...
Andrew767 Posted January 29, 2012 Share Posted January 29, 2012 Chris....Yes a 35mhz 6ex will buddy with a 2.4ghz 7cap...i had the same situation,checked with Ripmax who said yes...Tried it and of course it worked. Andrew Quote Link to comment Share on other sites More sharing options...
Lee Wilson Posted January 30, 2012 Share Posted January 30, 2012 Chris I used mine with an old 8channel 35mhz Futaba transmitter, I just had to get a square to round connector buddy lead. Have a look on Futaba web site, I'm pretty sure I've seen a compatibility table somewhere of which Tx can buddy up.CheersLee Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted January 30, 2012 Share Posted January 30, 2012 Agree with the guys above but you will need the correct lead...older Fubys use a round DIN style plug...newer ones have square.....most versions of the leads are available & Ebay is probably cheapest.... Quote Link to comment Share on other sites More sharing options...
Chris Procter Posted January 30, 2012 Author Share Posted January 30, 2012 Thanks all, i'll mooch around the bay for a decent box now. Cheers Chris Quote Link to comment Share on other sites More sharing options...
John Cole Posted January 30, 2012 Share Posted January 30, 2012 This is what the manual says on p37: "Compatibility: The 7C may be master or student with any Futaba FM transmitter compatible with the cord. Simply plug the optional trainer cord (For 7C series, sold separately) into the trainer connection on each transmitter, and follow the guidelines below." Note, I have a 6EX 2.4 that I buddy with a 6EXA, using a square to square lead. Futaba say you must NOT use a square to round lead with a 6EX 2.4 to buddy it to a round-lead Tx or you will damage the 2.4 Tx. I don't know if the same applies to a T7C, as the lead they refer to may only be available square to square. Quote Link to comment Share on other sites More sharing options...
GONZO Posted January 30, 2012 Share Posted January 30, 2012 There is another way. No leads used and a bit more high tech. Use THIS RX (FrSky FASST compatible Rx) temporarily attached to the Spectrum Tx (could be any Tx with a buddy port) and take the PPM stream out of the Rx and feed it into the Spectrum Tx. Both Tx switched on normally. You effectively have a 2.4 radio link buddy connection similar to the Futaba radio trainer link. In the reviews there is one by Christian giving a YouTube link to a demo. More info on the 'tinternet - do a search. Not done it myself with this combo but have rigged it up on the bench with other Rx and Tx combinations. HTH Quote Link to comment Share on other sites More sharing options...
GONZO Posted January 30, 2012 Share Posted January 30, 2012 Sorry, just checked YouTube and the vid has been removed. But, here's the link to the FrSky info Wireless Trainer . Quote Link to comment Share on other sites More sharing options...
kc Posted January 30, 2012 Share Posted January 30, 2012 People seem to have old 35 mhz Futaba 6 EX just lying around when they switch to 2.4. As these work as a buddy with 2.4 Futaba ask your clubmates if they have one to lend. Probably they will give it away! Quote Link to comment Share on other sites More sharing options...
Lee Wilson Posted January 30, 2012 Share Posted January 30, 2012 John, no problems square to round on the 7c and they are available, used one myself with my 7c.CheersLee Quote Link to comment Share on other sites More sharing options...
Chris Procter Posted January 30, 2012 Author Share Posted January 30, 2012 Thanks Gonzo, interesting set-up. Don't know how my instructor would take to that but it's certainly an option, John, thank you, as you pointed out the T7C manual does have a reference to using a buddy box but makes no mention of compatibility between various Futaba boxes and as the T7C doesn't have PPM in it's menu just instructor on/off it's caused me a bit of confusion especially when you read on various forums of the big "No round to square" etc. kc and Lee, thanks for the advice/info, my cheapest solution for now is to get a couple of cables (round to square and sq to sq ) and next time i'm at the field ask if someone would mind if I checked with one of their boxes? If all else fails we could always go back to box passing Thanks all Chris Quote Link to comment Share on other sites More sharing options...
John Cole Posted January 31, 2012 Share Posted January 31, 2012 Chris: this link shows you the compatibility table: Futaba trainer cord compatibilty The leads available are shown here: Futaba trainer cord types Click on the part-number for more details on restrictions. Note the square - square one is referred to as the 9C to 9C lead, for reasons that escape me. It doesn't list modern Txs on that page but they are listed on the Compatibility page. Edited By John Cole on 31/01/2012 11:06:32 Quote Link to comment Share on other sites More sharing options...
kc Posted January 31, 2012 Share Posted January 31, 2012 Maybe that Futaba data is pre 2.4Ghz, anyway the Futaba 6EX 2.4 manual clearly says to connect only to square micro type plugs and never to older round Din type. With so many good 35 mhz 6EX lying around unused it seems crazy to disregard this ( and mabe void the warranty? ) Quote Link to comment Share on other sites More sharing options...
Olly P Posted January 31, 2012 Share Posted January 31, 2012 kc et al, I use Sq to Rnd at my club with no problems. we have old tx's in the clubhouse and a selection of leads to allow use of them with most tx's.... Quote Link to comment Share on other sites More sharing options...
Lee Wilson Posted January 31, 2012 Share Posted January 31, 2012 6ex manual says not to use square to round but OP was about a 7c which is fine and what I used when I was training. Quote Link to comment Share on other sites More sharing options...
kc Posted January 31, 2012 Share Posted January 31, 2012 Lee seems to be correct when I study the online 7C 2.4 manual. But Olly's club might be in trouble if they assume the round to square will also work with the 6EX 2.4m because Futaba say this will damage the 6EX 2.4.There does not seem to be any known explanation for this difference i.e. round to square damages some 2.4 but not other 2.4. So presumably clubs must be wary of this ( who is responsible for any damage if the club instructor plugs in a round to square into a novices brand new 6EX 2.4 and wrecks the electronics? Does it really damage them? ) Quote Link to comment Share on other sites More sharing options...
Chris Procter Posted January 31, 2012 Author Share Posted January 31, 2012 This topic has been very informative, and seems to have plenty of answers, looks like my best option will be a good used 35mhz 6ex with square trainer plug and suitable lead to connect to my T7C. There's some really nice ones on the bay at the moment and are much better price wise than a more up-to date box, it is after all only for use as a buddy box so needs to be cheap as poss' Many thanks all Chris Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted January 31, 2012 Share Posted January 31, 2012 Posted by GONZO on 30/01/2012 17:12:23:There is another way. No leads used and a bit more high tech. Use THIS RX (FrSky FASST compatible Rx) temporarily attached to the Spectrum Tx (could be any Tx with a buddy port) and take the PPM stream out of the Rx and feed it into the Spectrum Tx. Both Tx switched on normally. You effectively have a 2.4 radio link buddy connection similar to the Futaba radio trainer link. In the reviews there is one by Christian giving a YouTube link to a demo. More info on the 'tinternet - do a search. Not done it myself with this combo but have rigged it up on the bench with other Rx and Tx combinations. HTHGonzo I believe there would be an issue with this approach. Even if the pulse voltages and polarities were correct for the spectrum Tx, the pulse (channel) sequencing would be different. So for example the aileron channel of the Futaba would be controlling the throttle channel of the Spektrum. Quote Link to comment Share on other sites More sharing options...
GONZO Posted January 31, 2012 Share Posted January 31, 2012 ON checking I think you are right about the different channel assignment sequence between Futaba and Spectrum . But, that would hold true if a lead was used. On another point it looks like the Spectrum buddy connection is only a signal(PPM) connection, if my info is correct, with no power - unlike Futaba. This would require a separate power supply lead from the Tx to the Rx. If a 35mHz Futaba 6ex is purchased it could be converted to 2.4gHz(FrSky system) by the installation of a FrSky 'Hack' module, either one way or telemetry unit HERE OR HERE then use a FrSky Rx, which are even cheaper than their Futaba FASST compatible Rx. There are threads on the 'tinternet on doing such a conversion, not that its difficult. This would give a second system to use(agreed on a different 2.4gHz system) for model flying as I believe the Futaba 6 Tx has limited model memory capability. Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted January 31, 2012 Share Posted January 31, 2012 Yep it does hold true if a cable was used - one of the reasons you can't. The Spektrum buddy lead doesn't carry power no. Just the PPM signal. I would think the simplest system would be to obtain another compatible futaba Tx and a suitable cable... Quote Link to comment Share on other sites More sharing options...
Peter Beeney Posted January 31, 2012 Share Posted January 31, 2012 Chris, you may well be be right about the Spektrum buddy lead, but I have some sort of nagging doubt. It’s just a 2 wire mono lead. When connected to the tx jack it has a battery voltage on the other mono plug, with the sleeve being positive and the tip negative. I ran into this awhile back, when I discovered there were two sorts of mono plug, Spektrum and everybody else. The Futaba lead has three wires, a transmit and receive, with a null crossover. The third wire is the common negative. The connections in the sockets are via series capacitors, thus preventing, or decoupling, any DC component, I believe.It’s a long time since I played about making buddy leads, Futaba anyway, my homemade version has lasted many years. I used a piece of screened wire, very flexible but strong, and filled the wire terminations in the back of the plugs with contact cement. The Futaba leads sometimes proved to be a bit fragile in this area, I repaired one or two, but this has stood up to all the pounding very well.I believe there is a Smart lead, somewhere, that connects JR to Futaba, someone was doing this at a site back in the nineties, I can remember that; the different channel conundrum did crop up, and as I remember that was also solved fairly quickly, too, unfortunately I didn’t bother to find out how.Futaba have now effectively prevented any tampering with the modern system, with their own design square plug, which you cannot purchase as a separate item. I couldn’t agree more about the compatible transmitter, I have a Spektrum DXe5 for Spektrum/JR and a SkySport 4 for Futaba, these have been fine up till now; but these might now be famous last words, of course, next time out we shall have a transmitter disagreement! PB Quote Link to comment Share on other sites More sharing options...
Olly P Posted February 1, 2012 Share Posted February 1, 2012 Regards use on a 6EX, this has been done in the past, with no problems, and both the 2.4 and 35 meg versions of the 6ex. I have an 8FG myself mind.... Quote Link to comment Share on other sites More sharing options...
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