Intefacing diagram for JR Radios. - How to interface with JR radios?

[Khizer]

Hi everyone,

I ve recently downloaded FMS and I am truly amazed at how good it really is.
Can anyone tell me the followig questions?

1) I want to use my
JR MAX 6 & MAX 66 MkII (japanese version of 652)
so both have PPM modulation so do I have to make only one such cord which will work with both of them or not?

2)So should I go for serial or parallel interface and which one is better?

3) I would appreciate if someone can give me guidence and provide me with the circuit diagrams for JR tranier cords

4)If the circuit not built correctly can it damage the Radio?

Thanks in Advance.

[Steve Lewin]

1. One cord should work with both
2. I prefer serial
3. The standard interfaces do not work well with JR transmitters. I have a modified version that seems to work (tested with Max 6, 652, 3810 etc), see
4. There are no guarantees but I don't see how you could damage the Tx unless you do something very strange indeed.

HTH - Steve

[Khizer]

Thanks steve,

there is some kind of problem with your website kondly can you email me about the details at
khizerbinyounos@engineer.com

Thanks.

[Steve Lewin]

Could you please tell me exacty what problem you have with the website. Several people have said they have trouble with it but very many others, including me from several different machines, seem to get in with no problems at all.

Steve

[Mike Roberts]

Steve - got onto your site fine.
Khizer and other JR users. I have just done a simple mod to the two transistor IRQ interface so it accepts the JR signal. All looks fine on my 'scope and I have had a good play with a JR max 66. See my website for details. Go to RC Projects>Flying Model Simulator>Circuit diagram JR. :biggrin:

Mike

[plasoneal]

I have attempted to build both versions of serial interfaces for JR's as detailed in this chain of notes. Neither of them are working with my JR Max 6. I've been told that the better of these two designs is the one found at

When I plug either of the cables in to the computer, (whether or not the radio is attached) I get a rapidly flashing cursor/hourglass for a while. This eventually goes away, but no matter what I do on the setup screens (16 bit or 32 bit) I can get no response.

I've tried this on one machine where the COM is COM1, and another where the COM is COM4. I also have tried all the COM port settings as recommended at (though I'm not positive I set the Flow Control to None, it might have just been XOn/XOff. I'll check that when I get home.)

The only substitution I made in the components was the transitors. I bought whatever small NPN and PNP transistors that Radio Shack had. (I don't have them with me or I'd quote the part numbers...)

Any ideas ?

(Since I couldn't get into this forum since last night until just now, I posted a similar query to the "Custom Electronics" web site. If you are "Mike Roberts", no need to reply twice.)

[Steve Lewin]

Even if you don't like my version of the i/f I'll still talk to you

Couple of questions, 1) you do have a fully charged battery in the Tx don't you ? JRs cannot draw power from an interface.
2) what operating system are you using ?

The serial i/f is not particularly fussy about COM port settings, it isn't actually using it as a true serial port. Mine runs happily with the port set with Xon/off and 38400 baud.

It's worth double checking that you have transistors connected correctly. There are so many different versions of the TO92 layout that it's very easy to make a mistake.

Steve

[plasoneal]

[Steve Lewin]

[plasoneal]

Steve:
I'm sure the TX buddy port works. I've actually tested this on two different radios. A JR Max 6 which is 6-8 years old or so, plus a newer "Expert" radio, which is actually made still by JR. I've used this pair in actual flight situations, so I know the TX's are working via the buddy ports.

You're correct, I've never seen any of the indicator bars move at all. I checked the transitor #'s last night.... I'm using 2n3904 for the NPN's and 2n3906 for the PNP. These are the Radio Shack part numbers. Since these don't match the diagrams, is that possibly where my problem is?

Paul

[Steve Lewin]

Those transistors should be fine (provided you have them the right way round ). Any similar small signal NPN/PNP transistors will do, I've used several different types from my "old component bag" without any problems.

It's difficult to know what else to suggest. I guess you don't have access to any test equipment like an oscilloscope. A digital multimeter perhaps ?

BTW did you get any response from Mike about his circuit ? I've not built that one myself though it certainly looks neater than my bodge.

Steve

[Rockfist Rogan]

How do I add small images (of transistor pin out) from my desktop?

Meanwhile BC 547 and BC 557 pinouts (both the same)

Looking from the top, with the flat to your left, it's :

c
b
e

RR

[plasoneal]

I have confirmed that I'm [now] hooking the transistors up correctly (though I've learned a bit in this process, that's for sure).

No, I don't have any more testing equipment other than my ohm/volt meter (isn't a digital one).

Haven't heard yet from Mike either...

Paul

[Mike Roberts]

Hi
Sorry to be out of the loop. Unfortunately my job takes me away periodically.
I have supplied loads of interfaces for JR without any problem so I am sure we can solve this one.
Please do the following checks to help us focus where to look:
1] measure the voltage on the lead from your transmiter, first with your meter on a DC range and then on an AC range. DC should read '0' and AC around 1v.
2] with FMS running, the interface connected, but not the transmitter measure the voltage across the 5k6 resistor on the 9 pin D (R5 on my circuit diag). You should get around 13v. Now connect your TX. This should now drop to 8v or so.
If these tests work focus on the FMS setup - see detail on my website. If they do not let us know what you see and we will take a closer look at you interface.

Cheers

Mike

[johnhlong]

Mike,

That looks like an easy test for most people to use. We should publish a list of these easy steps someware.

John