Gravityisnotmyfriend

My Feedback: (2)

I have an old focus 4 hitec radio with a bad switch - sometimes it works, sometimes it doesn't. I pulled the battery and x-tal out and made it a dedicated trainer box. I've used it with a focus 6 as a master and it works fine. When I hooked it up to my laser 6 hitec radio, it didn't work and a whisp of smoke came out of the laser radio. The laser radio still works, but I'm afraid to hook up the buddy box to anything. A friend of mine is gettting into RC and I want to take him up on the buddy box, so what should I do? Any ideas what caused the radio to smoke? I'm not sure what trainer cord it is, but I think its the tower hobbies brand.

warhwk

My Feedback: (3)

I would sure want to know exactly what component smoked. I wouldn't risk flying airplane in this condition. You might try taking it to a TV repair shop and have an electronic tech look at it. Otherwise, shipping back to Hi-tec would be the only other viable solution. (both radio's and buddy cord) An RC radio is not worth taking a gamble on safety. I was under the impression that Futaba/Hi-Tec/Tower were all compatible.

kamakasi

My Feedback: (3)

the tx to rx interface maybe compatible but the pin assignment may not. Have it checked by a qualified tech. As wawhwk said it ain't worth the risk.

JohnBuckner

My Feedback: (1)

The smoke may or may not have been related to the use of the incorrect buddy cord. However I would not use that Lazer untill the problem is found.

With Hitec radios only the Hitec directional cord should be used. The Hitec cord is a directional cord and the polarity must be observed. The plug marked student goes in the buddy box and the end marked master goes into the instructors box. If the cord you have is Tower brand then it is the old Futaba round plug and this is not a directional cord. Hitec Tx's can be buddied with Futaba Tx that use the old style round plug but will only work if the Hitec directional cord is used.

John

warhwk

My Feedback: (3)

I looked on Hi-Tec's forum. www.hitecrcd.com/cgi-bin/ultimatebb.cgi The Futaba and Tower trainer cords are not entirely compatible even though the pinouts are as JohnBuckner suggested. Maybe one of the Tech's at Hi-Tec can answer what might have gone wrong.

Gravityisnotmyfriend

My Feedback: (2)

Yeah, I haven't been using the radio. I did notice one thing wrong with it now. It seems that elevator channel only sometimes works on low rates, but always on high rates. I'm just thinking out lound here, but maybe since the focus radio doesn't have dual rates switches and the laser does, that may have caused the problem. That would explain why the focus to focus buddy system worked. I don't really feel like trying this theory by testing different combinations for fear of damaging another radio. I'll test the cord and see if all the pins are directly connected or if they cross over.

JohnBuckner

My Feedback: (1)

I did not suggest that the Futaba and Hitec cords were totally compatable. What I said was Hitec will buddy with the Futaba only when the Hitec cord is used and only on older Futaba Tx's using the round plug. I have used Hitec buddied with Futaba FM conquests.

John

Gravityisnotmyfriend

My Feedback: (2)

I tested the cord and this is how the pins are wired. 1-1, 2-3, 3-2, 4-4, 5-5, 6-6, 7(the metal outer shell) is wired to 7. The way this is set up, it shouldn't matter which end is plugged into which box. Does anyone know how the directional cords are wired? I could rewire this to match a directional cord since I only plan on using it on a Hitec - Hitec setup. Thanks for the replies.


-edit to include diagram (which was the point of this post)

Gravityisnotmyfriend

My Feedback: (2)

I found this info on another webpage:
Master Cord Slave Results
Eclipse Futaba Eclipse Works*
Eclipse Futaba Laser Works*
Eclipse Futaba Prism Damage to board
Eclipse Futaba Flash Damage to board
Eclipse Futaba Focus Damage to board
Eclipse Futaba Futaba radio Damage to board
Eclipse Hitec Laser Works
Eclipse Hitec Prism Works
Eclipse Hitec Flash Works
Eclipse Hitec Focus Works
Eclipse Hitec Futaba radio Works
Laser Futaba Laser Works*
Laser Futaba Eclipse Works*
Laser Futaba Prism Damage to board
Laser Futaba Flash Damage to board
Laser Futaba Focus Damage to board
Laser Futaba Futaba radio Damage to board
Laser Hitec Laser Works
Laser Hitec Eclipse Works
Laser Hitec Prism Works
Laser Hitec Flash Works
Laser Hitec Focus Works
Laser Hitec Futaba radio Works
Flash Hitec/Futaba Flash Works*
Flash Hitec/Futaba Prism Works*
Flash Hitec/Futaba Focus Works*
Flash Hitec/Futaba Futaba Radio Works*
Prism Hitec/Futaba Flash Works*
Prism Hitec/Futaba Prism Works*
Prism Hitec/Futaba Focus Works*
Prism Hitec/Futaba Futaba Radio Works*
Focus Hitec/Futaba Flash Works*
Focus Hitec/Futaba Prism Works*



It looks like the cord I have is wired the same as the futaba cord. That explains the line "Laser Futaba Focus Damage to board." That means that a Laser radio connected to a Focus radio with the cord I have makes smoke. Now I just gotta figure out how bad my laser radio is damaged.

carrellh

I don't think the pin-pin relationship is the diffrence between a Hitec cord and a Futaba/Tower/etc.
I think the Hitec 'one way' cord has a diode or some other device in one of the wires.
The Hitec cord costs about $15
Once your radio is fixed, that would be a very small investment to protect it.

KB9STD

My Feedback: (1)

The Hitec cord has 2 pins (I think 4 and 5<but I'd have to look) shorted together at the studunt end.Those pins are NOT connected through the cord to the Master radio,and serve to disable the rf(radio) transmission of the "Student" transmitter.Hitec and Futaba(and clones,e.g. tower) also wire the trainer port ground differently.Hitec uses pin 6 (the center pin) for ground,and Futaba uses the outside of the connector.The Hitec cord works in all cases(although you must observe the student and Master ends).The Futaba (and Tower or "aftermarket) cords can cause damage when used with certain combinations of radios.There are at least 2 possible reasons for the incompatibility,and Nobody(that I know of ) has been willing to try and sort it all out.The above compatibility list is the best I have seen.

warhwk

My Feedback: (3)

Thanks for clearing that up KB9STD.

That makes perfect sense. I have to remove the crystal on the Hitec TX when buddied with a Futaba master using a Futaba cord.

Gravityisnotmyfriend

My Feedback: (2)

KB9STD, did you find out how the cord is wired? I'd like to use my old focus 4 radio as a dedicated trainer box, but I need a hitec cord. I found a webpage, but it didn't have anything about hitec. I seem to remeber that hitec is also called multiplex. If that's the case did there is a schematic but it only shows to wires wired. Thanks for the help.

olivier

Hi,

For a trainer cord without any danger of frying anything :
-connect ground to ground (sleeve to sleeve for the round 6-DIN-240° connector)
-connect OUT-signal of slave to IN-signal of master (pin 2 of slave to pin 3 of master connector)
-do NOT use a powerline in the buddy lead

Now remove crystal from slave transmitter, both transmitters must be switched on, as there is no power provided from master to slave.

Check-out my website, in particular chapter 3 about Hitec.

Olivier