JR Buddy Boxes
 

I will be working with a student soon who is using a JR XF 421 radio. What other JR transmitters will work with this model as a buddy box? Thanks in advance, Dave

JR Buddy Boxes
 

I'm no authority on this... but I believe that you can use another 421 transmitter for a buddy box.

I just taught a student flyer at our field a while back and they had a JR 421 transmitter. No one had a buddy box so I called Horizon Hobby and asked them what they recommended. They recommended the JR Quattro ( which is what they sent me, minus a crystal ). It's a good basic radio that includes the trainer cord. No servos. I think I paid $50 for it.

I hope this helps!

Regards,
Mike

JR Buddy Boxes
 

Hi Dave,
The 652 and 8103 will work as well. They may ALL work, but a Quattro, 421, 652 and 8103 I'm sure of from personal experience. Remember, you DO need a charged battery in the slave with JR's.

JR Buddy Boxes
 

They will all work, just make sure that the buddy one is set on PPM with trim neutral, and as said before with a good battery.

Daniel D.

JR Buddy Boxes
 

Being that the 421 is a computer radio and the quattro isn't, I think you might have trouble if the master (the 421) has used any of the computer features like the travel adjust.

I had problems getting an old JR Max to work properly with a 421. I could adjust the servo direction but the travel on the 421 had been adjusted to 50% and the JR Max always wanted to give 100%.

The solution was to change and/or adjust servo arms and control horns so the 421 settings could be set on the 100% mark. The control surface movements were then equal.