Hello! I am a HAM Technician Licences Holder and I was wondering if anyone has any experience Building/modifying The RC transmitter modules from the back of RC transmitters. with a signal generator set for your desired frequency and NPN transistor CW Modulating the output from the transmitter, and some large MOSFETS as Amps, could you not get pretty good range? way more than a standard RC transmitter. this could even be applied to the telemetry radios.
If You cant help with that, then maybe you can help with a small part of it: what are the pinnouts of the 5 pin connector, and what is the signal type (UART, i2c, TWI, etc).
Replies
Sec. 97.215 Telecommand of model craft
An amateur station transmitting signals to control a model craft may be operated as follows:
(a) The station identification procedure is not required for transmissions directed only to the model craft, provided that a label indicating the station call sign and the station licensee's name and address is affixed to the station transmitter.
(b) The control signals are not considered codes or ciphers intended to obscure the meaning of the communication.
(c) The transmitter power must not exceed 1 W.
[54 FR 25857, June 20, 1989, as amended at 56 FR 56171, Nov. 1, 1991]
By the rules you are still limited to 1W for telecommand under amateur radio rules. I would read the rule to limit power out from the transmit amplifier, so you would be free to increase EIRP by using high gain antennas.
You can also use 902-926Mhz under ISM rules and you are similarly limited to 1W power out, but the power out limit is reduced when you start adding antenna gain.
As I recall, Telecommand is typically done around 52Mhz in the 6 meter band which would have better propagation characteristics than 900mhz, but the antennas would also be significantly larger for similar gain.
I have built an experimental 900mhz based system (FM, CPPM) which outperformed the turnigy 9x transmitted I have significantly (ISM rules, not part 97). Silicon labs, TI and other have processors integrated with sub-1ghz radios that can easily implement both the transmitter and receiver and provide whatever failsafe behavior you want. You can legally build and operate a few ISM transceivers (5 as I recall in the US) without going through equipment certification as long as "good engineering practices" are adhered to and you don't start selling anything.
You would probably get away with declaring the RC vehicle as a digipeater and running on 70cm at higher power levels. I don't think the FCC would approve if there was a complaint but if you operate at reasonable power levels, use proper station id and are courteous I doubt you would have a problem.
Dean NZ7KW
Unless you go into the ham bands (US ham?), the frequencies used for ISM are limited in the power output.
Ham bands can go the full legal limit. There are no commercial ham band TX units I am aware of.
Everything is going 2.4GHz, spread spectrum with other encoding integrated.
There is one ham band TX kit/hack: The MicroStar2000
-=Doug