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This device is very similar to the one being described in the previous project. The most important difference is that the LF signal exiting the ZN414 does not go to the transistor amplifier but to the power amplifier built around the LM386, which was used in some previous projects. Any other audio amplifier can be used instead, e.g. those on Pics.

This radio works with solar batteries that provide voltages between 0.5 and 2V. Microphones should be magnetic, high impedance (2k or more). The coil is wrapped around a ferrite rod 1 cm in diameter with 28AWG wire.

This is one of my favorite radio builds just because of how simple it is and how well it is able to pick up a lot of FM radio stations. I have browsed the world in search of a one transistor FM receiver. I have seen a couple but they were always attached to some sort of added device, such as another IC or another transistor for amplification in the receiver itself. Through my continued quest of searching for that too good to be true one transistor, I happened to run across a super-regenerative receiver, by Charles Kitchin, famous for his vast knowledge of regenerative designs. I printed out the schematic and made it. It turned out extremely well.

This FM radio receiver circuit is very simple to build and is powered by just a single 1.5V battery cell. Receiver consists of a regenerative rf stage, TR1, followed by a two of three-stage audio amplifier, TR2 to TR4. In some areas 3 stages of audio amplification may not be necessary, in which case TR3 and its associated components can be omitted and the free end of capacitor C5 connected to the collector of TR2. The critical part of the fm radio receiver is the first stage, TR1/VC1, where the wirings must be kept as short as possible. Coil L1 is formed by winding 8 turns of 1mm (20 swg) enamelled copper wire on a 6 mm diameter former, which is then removed. After that L1 should be stretched carefully and evenly to a length of about 13mm.

This is perhaps one of the simplest and smallest FM receivers for receiving local FM stations. It's simple design makes it ideal for a pocket sized FM receiver. The audio output of the receiver is amplified through LM386 amplifier chip that can drive a small speaker or headphones. The circuit is powered by three AAA or AA battery cells. FM receiver section uses two RF transistors for converting frequency modulated signals to audio. L1 coil and 22pF variable capacitor form a tuned tank circuit that is used for tuning to any available FM stations.

FM Radio Receiver IC TDA 7012T is very simple, but Radio This FM receiver has good sensitivity and selectivity. Single Chip TDA 7012T FM Receiver is to build an FM receiver requires a few additional components. Feature contained in FM receiver IC TDA 7012T is quite tempting to an FM receiver. Among features an FM receiver TDA 7012T is a low-voltage applications micro affability arrangement (MTS), Frequency Locked Loop (PLL) to 76 KHz range and selectivity of FM receiver with RC Filter. In an article by FM Radio Receiver IC TDA 7012T can be seen in the FM receiver circuit which can be made​​.

Perhaps this is one of the simplest and smallest FM Receiver that can receive the FM stations available locally. Its simple design makes it ideal for a pocket sized FM receiver. The output of the receiver drives a head phone.The circuit works off a small 4.5 volt battery or two 3.6 volt Lithium button cells.

This is the most simple fm radio receiver with good performances that works great even if the sensitivity is not too high. The working principle of this fm receiver may seem a little unusual. It is made of an oscillator (T2 and T3) that is synchronized with the received frequency of T1. This transistor works as a broadband preamplifier in VHF range.

High sensitivity TEA5711 receiver allows the reception of distant stations from over 150 miles (240 km) away. Good selectivity is obtained with narrow bandwidth ceramic filters. AFC automatic frequency control locks on stations for drift-free reception. Stereo separation which depends on signal strength is very apparent on strong signals. And with high quality headphones, the sound is rich with deep base and high treble, for hours of enjoyable stereo music.

The Super VXO uses two X-tals of the identical nominal frequency in parallel instead of a single X-tal of a conventional VXO. Nothing else is special. It can pull considerably more frequencies than the conventional one. About 40kHz for a pair of 10.15MHz X-tals, and 90kHz for 13MHz, according to my experiences.