USB RDS Coder Board using ATmega32
This board is a RDS coder using an ATMEL AVR ATmega32.
This board can be controled by a RS232 link, USB interface or SPI.
TA data is displayed wiyth a LED and can be controled by :
- Hardware input
- SPI (not yet implemented)
VERONICA 1W - 5W FM Transmitter
The Veronica is an easy to build and tune transmitter for the FM band. It's known for it's stability and clean signal, does not use any IC's or similar specialized parts, and it has a built-in tuning aid that makes it possible to tune it with no extra equipment. It's available in two versions, 1 and 5 watts.
Veronica 1W FM Transmitter
Veronica 1W FM transmitter is an easy to build transmitter. Veronica is also known for frequency stability, clean FM signal and uses no integrated circuit. The Veronica oscillator is actually formed from 2 oscillators which operates somewhere around 50 MHz in anti phase and the 2 signals are combined to form 100MHz FM radio signal. This kind of circuit design is stable and is amplified up to 1W by 2n4427 transistor. Veronica transmitter is equipped with a mini-mixer and so you may forget an external mixer. This consist from T1 transistor which amplifies the microphone signal before it is combined with CD player audio or PC signal. R1 and R2 are potentiometers (variable resistors) used to adjust the audio level. The component between R8 and C21 represents the oscillator which generates radio signal. D1 is a varicap diode (like a variable capacitor or trimmer) controlled by audio signal. C12, C13 and L1 determines the frequency.
Veronica 1W PLL FM Transmitter
The VERONICA transmitter is a very stable, powerful, and high quality FM emitter. Thanks to a PLL, the output frequency is controlled with DIP switches. Output power is approximatively 1W with a single regulated 13.8v supply ! (see specifications)
* High RF output power : 1W
* Full 87.5-108MHz range (100KHz increment).
* Very stable output frequency : Crystal reference & Phase Locked Loop.
* Professional input bandwith (fully RDS compatible )
* No complex tuning needed.
* High quality PCB
* Full documentation & construction details available
VHF Audio Video Transmitter
VHF Audio Video Transmitter
VHF FM Transmitter
The circuit is a simple 88-108 MHz VHF FM transmitter circuit. It is basically a VHF Colpitts oscillator capable of transmitting sound or music to any standard FM receiver. The circuit is powered by 9V battery which makes it easily portable. It also has a capacitor microphone which picks up very weak sound signals. The output frequency can be easily adjusted by potentiometer thanks to onboard MV2109 varicap diode and the frequency stability is quite good. The range of this transmitter is 100 meters.
VHF FM Transmitter MAX2606
If you want to be independent of the local radio stations for testing VHF receivers, you need a frequency-modulated oscillator that covers the range of 89.5 to 108 MHz — but building such an oscillator using discrete components is not that easy. Maxim now has available a series of five integrated oscillator building blocks in the MAX260x series which cover the frequency range between 45 and 650 MHz. The only other thing you need is a suitable external coil, dimensioned for the midrange frequency.
VHF Video Transmitter 60-200 MHz
Here's a simple video transmitter for VHF TV channel will accept baseband video input, hence it can be driven by most CCD cameras and VCR video outputs. It ouputs roughly 80mW and when used with a 40cm telescopic antenna over 100 meters range is possible.
The recommended Prescaler is ridiculously simple. It consists of just one IC, a TV tuner prescaler, the Philips SAB6456A, which can divide by 64 or by 256. This chip is widely available both new and in the surplus market at much lower prices than conventional divide by 10 prescalers.