astronomer1

I have two Futaba transmitters that I want to use in
the "Buddy Box" mode. One is a FP-T4NBF and the other is
a FP-T6NFK. Both are old but that works for me on a
limited budget. I have a Buddy Chord (FUTM4410) that
plugs into each transmitter. I want to use the FP-T4NBF
as the (Master Instructor's radio) and the FP-T6NFK as
(Slave Student's radio).

I can't seem to get this setup to work on the bench.
The T4NBF (Master) operates 4 servo's fine. When the
(Master) trainer switch is toggled to hand off control
to the (Slave), the signal goes away and the servo's
stop working. I have tried this setup with the (Slave)
both turned on and off and nothing works.

What am I doing wrong? Any information that you pass
on will be very helpful.

d_bodary

My Feedback: (85)

it's been awhile but if i remember correctly you need to remove the battery on the trainer box.

BuschBarber

My Feedback: (2)

The FP-T6NFK and the FP-T4NBF are both FM (not PCM) transmitters, so they should be compatible.

http://manuals.hobbico.com/fut/6nfk-6npk-manual.pdf

http://manuals.hobbico.com/fut/4nbf-4nbp-manual.pdf

They list the Trainer Cable as TC-FM.

In the Futaba world, the Buddy Box does not need a battery, however, if it has a battery, it does not need to be removed. You should not turn on the Power Switch to the Buddy Box or it will transmit on whatever channel it is tuned to. The Buddy Box gets it's power from the Master. I always used to pick up the Frequency Pins for both the Master and the Slave, if they were different, just to be safe.

It is possible that the Trainer Cord socket on either the Master or Slave could be defective. If you have the wrong Trainer Cable of if it is defective, you will have issues.

Occasionally, there can be incompatibilities between the Master and the Slave transmitters. Also, be sure the Master and the Slave are both either FM (PPM) or switchable to PPM.

http://www.futaba-rc.com/faq/faq-training.html

astronomer1

I failed to mention in my post that the receiver I am using is a Berg 4L which has Transmitter Signal Recognition(TSR). It also has a built in failsafe that can be turned on or off. I turned the failsafe off and the problem still exists. When I setup a Futaba receiver, everything works properly. The Buddy cable is good or the Futaba receiver would not work. I think the Berg 4L receiver's TSR circuit is the problem. The receiver sees each transmitter (4 vs 6 channel) as a different signal type and in turn ignores the 4 channel slave. As a result, the slave/student radio can't operate the Berg receiver. The 6 channel radio is the one that the Berg Rx recognizes because it is the master Tx.

That is just my guess as to what is going on. What I have to probably do is use a setup where each transmitter is identical and everything will be OK with the Berg ultra light receiver. Another option is to use a Futaba FM receiver that doesn't care how many channels the transmitter has.

A.T.

As answered much earlier today onother forum

Quote:

Originally Posted by astronomer1

Bummer Steve, about the Berg 4L not working with my two transmitters.
Sounds like I have two ways of solving the problem.
1. Ditch/trade/replace the ultra light Berg receiver for a Futaba or other non (TSR) receiver.
2. Get a different X-mitter that matches either the T4NBF or T6NFL that I have.
Now I need to "Con" one of you fellows into selling me one of your old and obsolete T4NBF orT6NFK FM Transmitters

Best solution for training purposes is #1.
Problems with TSR receivers have been discussed many times previously and even two TX of same make and model may may been manufactured at beginning and end of series with minor changes to the board as parts could have changed, this can also impact on the compatibility.

Buddy (Trainer) Box not working with Berg PPL, IPD and similar TX Signal Recognition Receivers.

See also sub Section "Trainer (Buddy box) cables - DIY " under
"Buddy Boxes. Servo Leads. Flight Simulator & Interface." at:
Alan's Hobby, Model & RC FAQ Web Links (quick search = Ctrl+F)

Alan T.