transmitter

1. wireless audio transmitters & receivers

Hi, I'm wondering how many individual wireless transmitters/receivers (stereo or mono is fine) in theory can operate in short range (3 ft. max) next to each other without interfering dramatically (via RF freq. UHF, or any other freq. or means that would be wireless). Prefer a solution with...
2. audiogurus FM transmitter

I have made aduiogurus FM transmitter mod3. Its working but my transmitter has much noise. so I made mod4. but it dosent work absolutely. I changed audioguru`s circuit 1) LM2931A => LM7805 2) 35p trimmer -> 30p trimmer. 3) 3mm former 8 turns -> 3.5mm former 8 turns I think what my problem...
3. One speaker is picking up radio module noise

I currently made a module to my project which isn't quite functioning correctly. It's 4 distinct parts on one board. The radio I/O, the two independent sound amplifiers out of the LM386's and the RFID card reader. This is the circuit: The actual inverter IC I used is 74HCT04 because it...
4. Power Transmitter controlled by ProMicro

I would like to cycle 9 volts of power to an RF Transmitter https://media.digikey.com/pdf/Data%20Sheets/Seeed%20Technology/113990010_Web.pdf via a 5 Volt ProMicro https://cdn.sparkfun.com/datasheets/Dev/Arduino/Boards/ProMicro16MHzv1.pdf. Is the transistor (perhaps the 2N222) the only...
5. What's going on in this simple FM transmitter, step by step?

https://www.google.co.uk/search?q=simple+fm+transmitter&biw=1600&bih=775&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiOjtWdgcLOAhXmIcAKHW0EAx4Q_AUIBygC#imgrc=kiQJiKelqDqVMM%3A I'm trying to understand this circuit and so far I read a lot about fm transmitter circuits, but there's no clear description...
6. 900 MHz FM transmitter

I bought a couple of wireless speakers that work through receiving 900 MHz, but the transmitter is missing so I would like to build a transmitter. But, I don't really know where to start. Will anyone give me some guidance? Treat me like the amateur that I am.