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I have a surface application where I would like to take the guts out of a Hitec Laser 6 radio Tx and install them in my own custom case.

Is this legal?

I also would like to control multiple pan-tilts (surface use) from a single transmitter, but I understand that switching xtals on a factory model R/C Tx is verboten by the FCC in the US, but legal in most other countries. Is this true? I don't understand why it would be illegal, but then I'm relatively new to all of this.

The information that is available on RC-cam is amazing. I did see something about controlling multiple cameras on an aircraft (from a single Rx?). Is anyone aware of a method to switch channels, or otherwise control two Rx from a single Tx for surface use? The receivers would be separated by some distance. I want to do it without wires.

Thanks!

Tom

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I have a surface application where I would like to take the guts out of a Hitec Laser 6 radio Tx and install them in my own custom case. Is this legal?

No. The technical info on file with the FCC includes packaging. Yours would no longer reflect the submitted data.

... I understand that switching xtals on a factory model R/C Tx is verboten by the FCC in the US, but legal in most other countries. Is this true? I don't understand why it would be illegal...

The required spectral tolerances in the USA are tighter than all other countries. We have commercial users in between our channels (big industrial stuff like cranes). The R/C makers are not willing to ensure that their designs will meet the required FCC specs under all possible situations. Multiplex's marketing says you can swap their Tx xtals. But according to what I can see in their FCC submissions, they did not present specific data that supported this. I guess they feel strongly about the stability of their RF amp design. Or, maybe they have deeper pockets and good lawyers?

Here is more Tx xtal info from Peter Berg (Berg R/C): http://www.bergent.net/crystals.html

BTW, licensed ham's can modify their 6-meter (50/54 Mhz) R/C transmitters. That angle may be a solution for you.

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Thanks once again! I can't believe how much I've learned in just a few days since I discovered this site. As they say about the pro golfers..."You guys are GOOD!"

Your PanCam sounds like just the medicine that my pan-tilt needs. Those floppy sticks are a pain. I can't wait to get started. I bought a programmer (like those mentioned by some of your users) and a lot of 6 chips...all for under $20 on ebay.

Tom

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So if I understand correctly, in the US all R/C TXs have a fixed channel that you can't change? Or have I misunderstood everything?

We often use 2 receivers and a single TX to reduce servo cable length on big models (airships, 8m long and more). We simply have the same frequency crystal in both receivers. If that's what you wanted to know.

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"We simply have the same frequency crystal in both receivers. If that's what you wanted to know."

Tom replies,

Uhhhm, no. I want to control two (or more) pan-tilt units, independently, from the same Tx, and using the same sticks for actual control. The idea would be to build a custom handset that has multiple xtal sockets. The sockets would be addressable (flip a switch).

The Rx in each pan-tilt would have corresponding xtals. This is for surface use, so one channel might be 60, and the other 61, for example. I might have a digital camera one one and a film camera on the other....or a still camera on one and a camcorder on the other, etc.

You did give me an idea, however, that I hadn't thought of (sometimes I don't see the forest for the trees).....use the second stick for the second P/T and trip the shutter(s) with switches. I think that would do it.

I hope this explains it?

Thanks for the reply,

Tom

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Okay. So to do it like this you'd better use good receivers that have a fail-safe. Because when you transmit on a certain channel, there will be nothing on the other ones but interference. I'm not sure if it's a good solution if you don't want the "unused" ones to move by themselves. The risk is greater if the channels are close to each other.

Using one stick for each is a solution, but of course you won't be able to control more than 2 units.

I would have an idea, but it's maybe a bit too complicated for what you want to do (PIC-based once more.)

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