has anyone built the JR interface at this website http://net-express.com/nexus/fmsinterface.html ? And does any one know if it will work with the JR XF421EX computer radio?

The interface on that page is for Futaba/Hitec Txs. It is unlikely to work with JR as they have a very different trainer output. It also depends what version of Windows you are running. None of the simple interfaces work with Win NT/2K/XP.

Steve

Is there any interface that will work with the JR 421EX and windows ME?

A generic (i.e., Futaba) parallel port interface will work with any JR just fine (I've tried several TXs)--you'll only need to change the connector.
If you'd like to make a serial port interface, search the official FMS Forum (there's a link at FMS home page) for postings by Steve Lewin. He's modified Futaba serial cable and made if work with JR as well.
Both these simple interfaces will work under Windows ME.
Boris

P.S. Just noticed that the previous reply was by Mr. Lewin himself!

Hi Boris, you've obviously done better than me because I've never managed to get the simple zener diode interface or the single transistor parallel version to work reliably with either the Max 6 or 622 that I've tried them with.

BTW I've pretty much given up on my serial interface now. Mike Roberts version at http://www.customelectronics.co.uk/fmscrktj.htm works as well, is neater and saves one transistor. That's the one I'd build. It should work fine with Win ME.

Steve

Are you sure the serial will work with the win 2000?

No, I'm absolutely certain that it will NOT work with Win 2000. So it's lucky that gambleb was asking about Win ME isn't it ?

Steve

There's a guy who sells them on ebay for $20. Or you can just bid on it. He makes them for just about every operating sytem.radio out there that I can think of.

I have an old Sanwa from 20 yrs ago, it uses a 6 pin DIN plug for its buddy and isn't like these new comp radios , any one know how to adapt this into an interface, help much appreciated.
LEDZ

Just try it with almost any of the Futaba/Hitec interfaces, wired as shown in http://www.welwyn.demon.co.uk/buddy.htm

Steve

Email me, I have one [email protected]

OK I built the interface as per the schematic at http://www.customelectronics.co.uk/fmscrktj.htm for some reason or another it won't work. What is the set up supposed to be? DO I have to go in somewhere and install a new driver for it or what? I run windows ME if that helps at all.

Have you followed the setup instructions on the same site (http://www.customelectronics.co.uk/) ? What results do you get in the FMS calibration screen ?

Steve

BTW you may also want to try the FMS forums where the real experts hang out. I know Mike posts there from time to time. Try http://cgi.ethz.ch/~mmoeller/cgi-bin.../ikonboard.cgi

OK THe number on the schematics BC547 and BC557 for the two transistors are not available at my local radio shack. Is there any supplement for them? Are they supposed to be different (NPN and a PNP) or is that just saying they can be either one? THe transistors I purchased are just mid range switching transistors, so I'm not sure If that is why it's not working. Please help.

Thanks ,
Brian

I guess you're not too used to building electronics. TR1 must be NPN. TR2 must be PNP. Other than that they can be pretty well any small signal transistors so there are hundreds of options that will work. They also have to be connected the correct way round. What transistors have you actually used ?

You still haven't said how you tried to set it up or what you see in the FMS calibration screen.

Steve

Well, I'm not used to building electronics I just fix them for the US Navy. As for the setup I did it exactly as per the web site you gave me (http://www.customelectronics.co.uk/) and on the calibration screen for the FMS nothing happens no matter how I set up the xmitter or the computer. I'm at work right now and I don't have the numbers on the transistors, but I will get them to you when I get home. I guess what I need to do is sit down and try and rebuild this thing again. Maybe I didn't put something in right I'm not sure, but I will get back to you on that

TR1 is a NPN 2N3904 and TR2 is a PNP PN2907A. Will these work?

Brian

Those should be fine, which only leaves connecting them up the wrong way round or something odd like not having it plugged into the correct serial port.

There is one thing, and I think this is right, I don't fly JR so I've only tested a few of them for various people. Did you realise that, because of the way the JR trainer system works, the Tx should not be switched on ? If you switch it on at the front panel it thinks it's the master and listens to the trainer socket rather than sending the signal out of it.

If you try all that and you're still not getting the calibration bars moving at all then I'm stuck.

Steve

What about this if I'm looking at the transistor with the flat side up and the leads pointing to the left, the middle lead is the base which one is the collector and which one is the emitter. That is the only other thing that I might be doing wrong? Thanks for the help. Hopefully I can get this thing working this afternoon.

Brian

Both should be standard TO92 packaging so top lead is emitter, bottom collector. See http://www.fairchildsemi.com/ds/2N/2N3904.pdf

Steve

Well I had a short time this morning to take my multimeter to the circuit and check it out. I'm starting to wonder about this diode I'm using. I was always taught that I diode is a short one way and an open the other. Is this not entirely correct because the diode that I have in my circuit has a resistance of almost 2Mohm (1.7M to be exact) and it is open in the other. Also the cord I was using has a 2 ohm resistance on either lead. Could those two factors be why it won't work at all? I still cant get the bars on the calibration screen to move at all.

thanks Brian

2 ohms on the lead almost certainly just means your multimeter is not very accurate at low resistances . The measurements on the diode may or may not be o.k. depending on what voltage your multimeter uses for its resistance test (if it's not higher than the diode forward volt drop it will show up as a high resistance). Is it a 1N4148 or some other diode ? The readings could also be those of a zener diode, which won't work in there.

With it all plugged in and FMS running what DC voltage do you see between ground (pin 5) and each end of the diode ?

BTW, when you visited the FMS forums did you read the earlier threads in "Serial Interface" ? There have been plenty of similar questions relating to this same interface.

Steve

hI my lead was made fo a futaba useing a pic chip for XP can any one tell me how to get it to work on my JR 3810 . I swaped the plugs over and nothing???????

It needs a modification to the front end because JR use completely different signals to Futaba. Difficult to give details without knowing exactly which PIC interface circcuit it is.

You can try just connecting a capacitor of about 0.1uF in the lead from the Tx. That might help but it probably won't be enough.

Steve

Hi I do not know the details but it was made up for my feild force 6 I have now got my self a JR 3810.