Hi everybody,

I have a question about my buddy box. I bought the JR S400 model and I was wondering if I could use it as a regular Tx if I put a chrystal in it?

thanks!

Pierre

If it's a true buddy box, it probably does not have a transmit amplifier internally. The buddy box I have, which is a Futaba, only has the stick gimbals and the connector to join it with the main transmitter. In fact, it gets whatever power it may need from the master transmitter, meaning there is not even a battery in the buddy box.

DS.

JR buddy boxes have to have the battery in them in order to work. But, they do not have the transmission circuit in them that would make it a true radio. All they do is convert your stick movements into electrical signals and send that over the cord to the master radio in order to be transmitted to the plane. So the answer to your question is no, you cannot make it a radio by putting a crystal in it.

Ken

Ah.. Ok, Ken. I didn't realize the JR buddy box needed the battery. My Futaba does not, and I believe neither does the Airtronics. But, what seems to be common to all of them is that they don't have the electronics.

CG,
Yes, JR's have to have a charged battery in the buddy box to work properly. They are the only brand that does this. Futaba, Airtronics, and Hitec all work without a battery in them.

Ken

Thanks, Ken. That's good to know. I'm sure it will come up at the field one of these days.

There ya go, Buzz (Pierre).. you always learn neat new stuff at RCU!!

yeah that's thrue, I got more than I asked! thanks to everyone.

NUTS! That anwsers my question too....thanks Buzz! You saved me money and time and possibly the loss of a plane.

Buzz,
I also have the S400 as my buddy box and I have bought a crystal and used it as a TX while my other JR TX was in for service. After a range check the S400 worked great. I was able to confirm I could do this by asking the same question in the radio forum.
Indy Park Flyer
Hangar 9 Alpha 40
Hangar 9 Pulse XT

I got my S400 from the AMA buddy box program when I'm not using it as my wife's buddy box I stick a crystal in it and use it for my park fliers. It works great. I guess some AMA batches of the S400 went out fully loaded minus the crystal.

It's illegal in the US for you to put a crystal in a transmitter without it being tuned by an authorized service center. You placing a crystal in a transmitter is the same as a user changing the crystal and is covered by FCC regulations. The penalties for doing can be as high as $10,000 per incident.

Ken

Thanks ken I'll make sure to send my controller in every time I want to switch from channel 54 to 56.

That's what the law requires. But laws are meant for other people, not you. Right???

Actually Bruce I did not know that it was a law. Part 15 which is what our transmitters fall under in the FCC is kind of fuzzy. Now that I do know I will have to send it in. I’ve seen hundreds if not thousands of people over the year’s change their crystals even at AMA events and never once thought or heard anything wrong about it. All I can say is I’m glad I have been informed and even more glad that I’ve switched 90% of my hanger to 2.4ghz with the last 10% due to be changed this next month. So yes to answer your question the law does apply to me.

One last thing Bruce some people on RCU wastes no opportunity to degrade JR equipment. Even if that means not being 100% informed or truthful about it. In the few short months I’ve been on RCU I’ve noticed this trend as clear as night and day. Personally I could careless what brand of radio anyone uses. At this point in time I choose to use JR a few years from now when I go to upgrade I might choose another brand. I have 0 brand loyalty and will always choose what suits me best. I will not degrade other brands based on erroneous information or because I think brand loyalty requires me to do so.

"One last thing Bruce some people on RCU wastes no opportunity to degrade JR equipment. Even if that means not being 100% informed or truthful about it. In the few short months I’ve been on RCU I’ve noticed this trend as clear as night and day. Personally I could careless what brand of radio anyone uses. At this point in time I choose to use JR a few years from now when I go to upgrade I might choose another brand. I have 0 brand loyalty and will always choose what suits me best. I will not degrade other brands based on erroneous information or because I think brand loyalty requires me to do so."

Where'd that come from? Are you implying that I made such statements? While it's true that I personally prefer Futaba I also don't care what others fly and instruct students on most major brands. I personally own buddy boxes that worj with most of the major systems too so I'll always be ready for whaatever my students show up with.
I certainly didn't notice anyone degrading JR in this thread, did YOU?

JR, Futaba & Hitec do not list "Buddy Boxes" on their inventories ex factory. Some large businesses strip complete sets to sell the crystals and antenna along with the servos, switch harness etc as separate items and then sell the TX with a training lead as a "Buddy box package". This to maximise profits from slow selling or surplus units which have been superseded. Every JR & Futaba "Buddy box" seen to date has required only a battery, crystal and antenna to be fully functional. (USA is the only country that restricts user changing crystals in TX or module - here 72 MHz TX crystals are available off the shelf, we simply plug in range test and use.)

Sorry, must disagree. Computerised Futaba, Hitec and Airtronics do need batteries in the slave to operate and board/screen light up as soon as lead is plugged in. The slave's switch must not be turned on, refer to TX compatibility and requirement for batteries Hitec Trainer (Buddy) System Update - New "Stereo Plug" system and how to use.
Refer also to TX 2 TX = buddy box compatibility problems between different brands of transmitters
Regards
Alan T.
[link=http://homepages.ihug.co.nz/~atong/]Alan's Hobby, Model & RC FAQ Web Links[/link]

That's odd. When I was in training, I used an Airtronics buddy box and never had a battery to charge in the buddy box. Perhaps you are thinking of using an RD6000 and another RD6000 as a buddy box? In that case, I agree. This is so with any other transmitter to transmitter as a buddy box configuration. When using an actual buddy box, there is no battery in the buddy box, just in the master transmitter. I have both the Airtronics and Futaba buddy boxes and neither have a battery in them.

In which case you are/were probably using simple old fashioned non computerised TX without EPA, dual rates, elevon / Vtail mixing etc. Like computers, modern TX are changing rapidly as even the modern 4ch Hitec Laser 4 & 6 must have a battery installed when used as a slave.
With many modern models requiring 6 channels for dual ailerons/flapperons the days of a simple 4ch TX as a buddy box are limited.
Please read all of the information relating to updated trainer systems supplied with my last post.
Regards
Alan T.
[link=http://homepages.ihug.co.nz/~atong/]Alan's Hobby, Model & RC FAQ Web Links[/link]

Great website AT. I have used it alot.
thanks.

Alan,
I've been an instructor for almost 9 years now and I can tell you without a doubt that a Futaba, Hitec, and Airtronics buddy boxes DO NOT NEED a battery in them. Yes, I use the bare bones basic radios as buddy boxes when I train a student. IMHO all of the "bells and whistles" of a computerized radio are not needed when teaching a student. In fact, it can actually hinder the training process. A student learning to fly RC needs to learn how to fly the plane, not rely on a computerized radio to take care of some functions for them. The radio can actually become a crutch for the student and they will never learn to really fly the plane properly. All of those nice features are great later on down the road, but at this level the student needs to learn the basics of flying and doing it for themselves. You can use the fancy computer trainer systems that you quoted in your posts if you want, but IMHO you are doing the student a disservice and not training them fully.

Even full scale pilots start with the basics and build up. Do you think that F-18 pilots start out in the cockpit of a multi-million dollar fighter?? Of course not. They start out in a single engine prop driven plane.

Ken

No one I know is going to buy a specific trainer box to help out a new person that shows up. We use what we got to help with the training.

A computer radio, used as a buddy box, is no different than using any other buddy box. The first goal of the new pilot is orientation of the model verses transmitter inputs. Nothing more.

Actually, I own 4 buddy boxes that I use to train students. I have an Airtronics, Hitec, Futaba, and JR buddy box. So as long as the student shows up with one of the big 4 radios I have the buddy box to train them with.

Ken

And our club has cords to fit just about every combination AND like RCKen, a couple of us keep TXs in the car to match almost anything that shows up. Although most times, lessons are scheduled so we know what is needed.

I also have four specific trainer boxes for my students and the necessary cords that go with them. Seems like "will" doesn't know any "real" instructors.

I also carry the various brands needed to hook up a student for a training session. I've been training students since about 1974.

The point of my post was not to discuss your chest thumping that you train

The point is that it makes no difference, at all, if you use a computer radio as a buddy box.