I saw this guy take the back off his transmitter and remove this small black box,he said he was changing frequencies by turning two small screws on the bottom then put that little black box back into the main box,it sounds better than changing the crystal.
Has anybody heard of these ?,how good are they and how expensive or a webpage.
Thanks

They are synthesizers. They change frequencies without having to retune your Tx.

Hitec makes the Spectra. Futaba has them for the 9CAP and the 9Z and the 8U. It's called the TK-FSS. Both only work on radios that have a removable RF deck.

The synthesizer for the 9C has not been released yet, to the best of my knowledge. The only one Futaba sells is for the 9Z, which is the TK-FSS.

Tower Hobbies lists the Futaba FP-TP-FM as the module for the 9C:

http://www2.towerhobbies.com/cgi-bin...I=LXH256**&P=V

Jesse

that module isn't FCC certified for the 9c. the 9c version SHOULD hopefully be released soon. (read the description, it lists the tx's it is compatible with)

Kramer, the very next line says:
----------------- This also is the Module for the New 9C.----------------------

I wonder if the 72mhz module is out.

Polk also makes a transmitter that can switch to any channel. But it's all done in the computer, no knobs to turn or anything like that. They also have a receiver that tunes itself to any transmitter. They're rather cool and useful at busy fields. (However, the Polk doesn't have a trainer plug, so I don't usually mention it in the beginners forum).

So does it tune itself to the transmitter putting out the most power?

"I don't have it, do you have it?"
"Yep, I've got it, no wait I don't."

Hey, I've got it over here!."
Dennis-

Heh, good one. No, it's not that flaky.

It has a "set" button that you hold as you turn on the RX. When it does that, it comes up in a search mode. At that point, it does, in fact, find the most powerful transmitter and lock on that channel. From then on, it stays on that channel, until the set button is used again.

As for being the strongest transmitter, all you have to do it turn your TX on, and put it next to the airplane. Since TX power drops off as the cube of the distance, unless someone else has their TX right next to the plane as well, the RX will have no trouble figureing out which is the one you mean.

Now, if you wired up a device to turn off the RX then turn it back on in flight with the "set" button pushed.... Actually, it wouldn't work . When in "search mode" the RX slowly moves the aileron servo back and forth to tell you it's searching, and it does take a couple of seconds, so you'd splatter the plane for sure. Still, it's a funny concept.

Oh, I forgot to mention, the RX comes with a set button on a lead. it uses a regular servo plug, and goes in a special port marked (get this) "set" on the RX. So you can set the RX to your channel, then unplug the button and stick it in your field box or whatever. Or, you can mount the switch anywhere on your plane. The switch just hooks the signal line to ground, so you can even make your own "set" switch with as long a lead as you want, and mount it anywhere you want. The the RX isn't very expensive either. IMHO, it's one of the "great secret products" out there.

Upon further examination, the link above is for a single frequency module in the 50mhz range.

That looks about the size of it and the two screws are on the bottom,i say screws because it is slotted and there are numbers around the screws like the face on a clock,i guess you turn or click it to the desired settings then snap it back in place.It seems like a good idea for changing freq's on the spot.

I use a Hitec With this "Spectra module" and it works fine. One thing though, this transmitter uses a lot of power to run , so I replaced the original battery pack with 1600 mah Nimh's . Now it has enough power for 6-7 hours run time. I charge it the same way as the original stock battery pack.

Geistware,
In the link from Tower about the FP-TP-FM module, the description title says TP50 & 72 FM, meaning that it comes in either 50 Mhz or 72 Mhz. Also, down in the tech notes it says:

"INCLUDES: One 50MHZ or 72MHZ Transmitter Module"

So, according to Tower, it is the correct module for the 9C. Tower's descriptions can and have been wrong in the past, so knowing someone that has actually tried this module on the 9C transmitter would be the way to know.

Jesse