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VHF FM Aircraft receiver:
VHF FM Aircraft Receiver is a superregenative receiver developed for listening to FM transmitters but also tunes the aircraft band and the top portion of the FM broadcast band. Receives both AM and FM (107mHz to 135 MHz). You can use this receiver with the any FM transmitter. The receiver is amazingly simple using only one transistor for the receiver section and one IC for the audio section. This circuit is a self-quenching regenerative RF receiver also known as a superregenerative receiver.
[via]
VHF FM Aircraft receiver - [Link]
This small transmitter can reach more than 1 km under good conditions . The input can either be an electret microphone or other audio source. The frequency is given by CV (trimmer common 2-20 or 3-30pF) and L1 4 or 5 turns of 22 AWG enameled wire with a diameter of 1 cm with air core.
FM transmitter with 2N2218 - [Link]
electronicsblog.net writes:
Old wish to make digitally controlled FM tuner come true when I found on Ebay cheap module with TEA5767 (Low-power FM stereo radio for handheld applications).
This module size is only 11.2mm x 11mm. TEA 5767 supports I2C.
For antenna i have used just 75 cm long wire, because that is 1/4 of wavelength at 100 MHz. TEA5767 doesn’t have audio amplifier, sound output level is very low, headphone can not be connected directly. During testing i had connected audio output to PC audio system.
Arduino FM receiver with TEA5767 - [Link]
electronics-diy.com writes:
With this Stereo FM Transmitter with BA1404 you will be able to create a mini stereo FM station and broadcast to your entire home, a simple way to have an audio link wireless with ease. With the FM transmitter BA1404 Hifi Stereo you can stream your music from your iPod MP3, satellite receiver, computer, DVD player, Mobile Phone, MP4 player and MP3 and other audio source directly to an FM receiver with crystal clear sound.
Stereo FM transmitter - [Link]
This page describes hardware and software design for digital USB FM transmitter, called FmStick. This hardware does not contain analogue parts (except RF part). The main idea – is to create transmitter, that looks like usb flash stick. This idea is not new, You can see some of this designs in market, like Griffi RocketFM or Keene USB FM Transmitter, both avaliable on Amazon. But device, described below – is different. It does not have analogue sound parts at all, and it supports RDS, and it is powerful.
The main features of this device are:
- Transmit Frequency: 76 … 108 Mhz
- Transmit Power: -60 … 20 dBm[1]
- Audio Compression: Yes
- Audio Limitation: Yes
- Audio Signal Measurements: Yes
- Pre-Emphasis: 0/50/75 uS
- RDS: Yes
- RDS RadioText: Yes
- RDS Time: Yes
- Drivers Installation Needed: No[2]
- Software Needed: No[3]
- LEDs That shows state: Yes
- External power needed: No
FmStick Digital USB FM Transmitter - [Link]
@Wolfram_Alpha FM Synthesizer – play sin(440 pi t + 16(1 – t) sin(711.92 pi t)) – [via]
@Wolfram_Alpha FM Synthesizer - [Link]
The Si4840 and Si4844 from Silicon Labs are the first CMOS AM/FM/SW radio receiver ICs with analogue tuning and digital display that integrate the complete receiver function from antenna input to audio output. Based on Silicon Labs’ proven and patented digital low intermediate frequency receiver architecture, the Si4840 and Si4844 deliver superior RF performance and interference rejection. The integrated control algorithm provides an easy and reliable control interface while eliminating all of the manually tuned external components used in a traditional receiver. [via]
AM/FM/SW receiver integrated on a single CMOS chip - [Link]
An introduction to AM/FM active antennas: [via]
This article is a reference design (RD) for an automobile AM/FM active antenna. The RD presents the flexibility of the MAX2180 active antenna low-noise amplifier (LNA) and shows how to set the AM and FM gain and the automatic gain control attack point. Single and dual antenna schematics are detailed, including the input and output matching circuits. Using this design together with the data sheet and device’s evaluation (EV) kit, a prototype antenna can easily be developed for a wide range of active antenna requirements.
App note: AM/FM active antenna - [Link]
The Park Ranger is an ultrasonic-ranging prototype designed to assist drivers who are backing into tight areas. The ranger uses ultrasonic pings to measure distance to the object behind and indicates this distance by sending audible tones to your FM radio. Optional panel-mount LEDs offer visual aid for calibration as well as warning drivers behind you.
The intention of this project is to demonstrate the Amani64ʼs ability to serve as a rapid-prototyping tool for applications typically covered by proprietary modules. While a commercial ultrasonic-ranging module could be used in this project, the Amani64 is used in instead to tailor the system to our exact needs. The user can drop in blocks of IP, whether open-source or their own, to create a custom application over which they have full control and ownership. A CPLD-based prototyping board is useful for any application that requires logical circuits, whether they be parallel or sequential, that space, cost, and vendor-delivery times are a concern.
DIY Park Ranger – [Link]
Sean Michael Ragan writes:
This circuit is commonly credited to Japanese multimedia artist Tetsuo Kogawa. It takes audio input through a 1/4″ phono jack and, constructed as shown, without the optional antenna connections, will broadcast an FM radio signal about 30 feet.
Micro FM Transmitter – [Link]
