Hossfly

YOU may wish to review the posting I have made in the Hitec Radio Support forum concerning a discovery I made today. MORE details.

Got caught at field without my box of basic slave transmitters and proceeded to use my Hitec Prism 7 with Spectra for a buddy box to instruct a Futaba Master.

Thankfully we found early that in the SLAVE position, without battery, the Prism 7 bleeds Master Radio battery to operate computer and TRANSMITS on the SPECTRA frequency.[:@][X(]

Had to remove Spectra module. Bad News. Be careful out there.

ChuckAuger

My Feedback: (12)

Better call the AMA

rc-sport

My Feedback: (12)

LOL Chuck

easysport

My Feedback: (2)

The solution is not to use a computer radio as a slave why would you want to anyway? Most people who are using the slave are newbies anyway and dont need bells or whistles . I turn my slave off and have had no problems getting it to work with my Prism as master.Did you try turning on the Prism when it was used as a slave or was it a different channel?Mabey it would work that way with antenna unscrewed.

Hossfly

[quote]ORIGINAL: easysport

The solution is not to use a computer radio as a slave why would you want to anyway?




Basic Reading 101

tiggerinmk

I would (and did). I used a JR XP631 radio (computer) with a JR Quattro (basic).
After initially using the 631 as the master and the Quattro as the slave, I decided to swap them around (Yup, a newbie supplying and setting up his own BB system).
Why?

1. I was miffed that the instructor got to use my shiney new radio while I had to use the basic one.

2. Using the radio that you are going to continue on when you lose the buddy box is better than to have to get used to a defferent radio in addition to soloing.

3. The Instructor (using the basic radio) can use full rates, while I (the student) get the option to use low rates.

tiggerinmk

Maybe it just works when you use a decent brand of radio...

P-51B

My Feedback: (5)

I thought it was common practice to use only equipment from the same manufacturer when doing the master transmitter / buddy-box thing?

Matt Kirsch

My Feedback: (21)

It is a well-known fact that a Hitec radio used as a buddy box will transmit if you use a regular Futaba buddy cord. The fact that the radio in Horrace's case was a computer radio has absolutely nothing to do with the issue.

If you are using ANY Hitec radio for the student/slave box, you MUST use a genuine Hitec buddy cord. Hitec buddy cords are unidirectional; they have a clearly marked "MASTER" end and a clearly marked "STUDENT" end. The cord is wired such that it disables the buddy transmitter from transmitting.

tiggerinmk

It is a well known fact that well known facts are only well known to those that know them.

In practice, this is probably restricted to those who have learned the hard way and those who have been informed by those who have learned the hard way.

There are probably many other owners of both Hitec and Futaba radios that haven't the foggiest idea that this would be a problem and wouldn't think to try and buddy box radios from two different manufacturers.

I doubt if either Futaba or Hitec mention the implications of buddy boxing a transmitter from another manufacturer in their instructions manuals. Just bacause they both use the same connector I don't see how you can just assume that it'll work.

Hey, my JR radio uses a mini jack plug. Maybe I can plug a microphone into it and buddy box it using voice commands?

BasinBum

My Feedback: (2)

And thanks to Hoss for bringing this up cause now we all know from someone who learned it the medium hard way and was sort of corrected by someone who thought we already knew it even though we didn't.

FLYBOY

My Feedback: (11)

Exactly, and glad he figured it out before things went really bad.

Matt Kirsch

My Feedback: (21)

It's a well known fact that just because a fact is well known doesn't mean that everyone knows it.

Crashem

"It's a well known fact "

Reminds me of Cliff Claven from Cheers lol

Hossfly

Yes, Matt, you are right. I have interchanged for years and never knew that I was screwing the pooch.
I only proved that one of my favorite cliches in my 41 years of aviation is still correct, and that is"
"What one does NOT know isn't as dangerous as THAT WHICH one KNOWS FOR SURE BUT AIN'T SO!"

In this case I KNEW the B-cords were interchangable, however just because the plugs fit doesn't prove the product is the same. EXPERIENCE is what I get, just before I need it !!! Hopefully my experience will assist someone else and save a plane.

From HITEC: >>>>>>>>
Hello Horace,

I hope I have a correct understanding of the problem you are having. When you use a Futaba cord with a Hitec and Futaba transmitter combo, both transmitters will broadcast on frequency. To eliminate this, either use a Hitec one way cord or pull the module or crystal out of the student transmitter.

Regards,
Tony Ohm
Service Manager
Hitec RCD/Multiplex USA
<<<<<<<<<<,

YES SIR, I will, I will.

the troll

Great info here. A while back one of the instructors had his transmitter to burn out the RF deck of his trans. He did not have knowledge the problem about the unidirectional cord and the magic smoke came out of his trans. apparently they noticed the meter showing power up but didn't give it much thought. Scary part is that they took flight numerous times before the RF deck smoked. Could have been much worse.