Where can I find a diy-type Propeller AM radio transmitter project?
AwesomeCronk
Posts: 1,055
Looking to make a short range transmitter, ideally with variable frequency. Spin/Pasm code is preferred.
Comments
Bean
Did you happen to find this?
http://forums.parallax.com/discussion/105674/hook-an-antenna-to-your-propeller-and-listen-to-the-radio-new-shortwave-prog#latest
It might be a good starting point for the receiver side of the AM radio transmitter project you are working on. If you're going to transmit a signal, I suspect you will need a receiver.
Otherwise, your transmissions/receptions could experiment a lot of interference, due to gap discharges, commonly present at the insulator spacers, near each of the wire-holding metal towers that route HVAC trasmission lines (a extremmely commom phenomena, at least in my country).
There are also the possibility of HVDC power transmission systems, with totally different parametrization and behaviour, but they are not directly connected to commercial/residential areas; they must be converted to HVAC before routing to the consumers.
https://electrical-engineering-portal.com/7-bad-effects-corona-transmission-lines#electromagnetic-interference
Jim
If your operation will be limited to daytime or early evening, you probably don't need to bother.
Bob
Mind you, as a teenager I would ride on the bus with my AM transistor radio, except I wasn't listening to it, I'd just sit near someone who was listening to theirs and with the volume down I'd turn the tuning dial until the local oscillator would start to interfere with the station that they were listening to. Amid their confusion as to why their radio was playing up I'd have my silent little geek giggles
But that makes you wonder about all the inadvertent transmitters such as electrical equipment and HV power lines that interfere on that band.
https://www.fcc.gov/oet/ea/rfdevice
Across the room may be okay. A quarter mile? Not so much.
-Phil
Range wise, if I can reach the car out front and the radio on my desk, I’m good!
-Phil
https://fcc.gov/media/radio/low-power-radio-general-information
And here's some highlights from that page:
"Part 15 Devices
Unlicensed operation on the AM and FM radio broadcast bands is permitted for some extremely low powered devices covered under Part 15 of the FCC's rules. ... On the AM broadcast band, these devices are limited to an effective service range of approximately 200 feet (61 meters). See 47 CFR Sections 15.207, 15.209, 15.219, and 15.221. These devices must accept any interference caused by any other operation, which may further limit the effective service range.
Prohibited Forms of Low Power Operation
A license or a construction permit is required for all forms of operation in the AM and FM radio broadcast bands which cannot be classified as Part 15 or Carrier Current or Campus Radio Stations.
Penalties for Operation Without A Permit or License
The Commission considers unauthorized broadcast operation to be a serious matter.
Presently, the maximum penalty for operating an unlicensed or "pirate" broadcast station (one which is not permitted under Part 15 or is not a Carrier Current Station or Campus Radio Station) is set at $10,000 for a single violation or a single day of operation, up to a total maximum amount of $75,000.
Adjustments may be made upwards or downwards depending on the circumstances involved. Equipment used for an unauthorized operation may also be confiscated. There are also criminal penalties (fine and/or imprisonment) for "willfully and knowingly" operating a radio station without a license. sort by DON'T DO IT!
See recent Enforcement Bureau orders for unlicensed operations.
"
There is more info on that page at at the links on it.
Tom
Jim