Another one...
Owing to the success of my first stereo FM receiver with the discontinued and hard to find TEA5711 and TDA7050 integrated circuits, I decided to build a second and more compact version. This is the unit you see here.

Slightly different...
Compared to the original, this receiver is smaller in size, it is housed in a homemade case, it has no balance control, the vernier mechanism is part of the tuning capacitor, and it is powered with two 1.5 volts AA batteries.

Similar performance...
The performance of this receiver is similar to the original. High sensitivity allows reception of distant stations from Cyprus, 240 km (150 miles) away. Good selectivity is obtained with narrow bandwidth ceramic filters. AFC (automatic frequency control) locks on stations well for drift-free reception. Stereo separation (effect) 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!

Compared to the Sony ICF-SW7600G...
I compared my receiver to the Sony ICF-SW7600G. Needless to say, I used the same headphones (Koss Pro35A), the same station and the same broadcasted material. Stereo seperation: my receiver is better. Mid-range frequencies (around 8 khz): The Sony wins. Stations selectivity: I couldn't tell the difference. This led me to the conclusion that even the big companies will cut corners to reduce prices and increase sales!

The receiver is housed in a 6 x 4.5 x 2 inch box I made from pieces of single-sided PC boards. Controls from left: on/off, volume, stereo/mono and tuning. A 7 to 1 vernier embedded in the tuning capacitor coaxial shaft offers smooth tuning. Stereo reception is indicated by the red LED. The stereo/mono switch allows clearer reception of weak stereo stations. High quality stereo headphones with 32 or 60 ohms impedance can be used to listen to the receiver. A removable telescopic antenna can be swiveled, extended and collapsed for best reception.

The circuit was built "Manhattan style" on a 2 13/16 x 3 15/16 inch piece of single-sided PC board. An SDIP socket was used with the TEA5711 to allow easy connection of the components. Slug-tuned coils (red squares) were adjusted and sealed with wax for stability. Ceramic filters and resonator are on the right side of the TEA5711 IC. Black trimmer pot (lower left) is adjusted once for best stereo separation. Stereo amplifier TDA7050 sits in a DIP socket (lower right). Dual-ganged volume control is at lower center. Dual-ganged variable capacitor with coaxial vernier shaft is at left. 4 pieces of PC boards with center nuts at the corners are used to hold a cover. Battery holder at top right holds 2 AA batteries which supply 3 volts to the receiver.

Close-up view of the board. A printed circuit was not necessary to assemble the high frequency circuitry. The copper plane served as a common ground and improved stability. Bending the pins of the TEA5711 SDIP socket was a frustrating experience as they were fragile and prone to breaking; the missing pin on the left actually broke, but luckily it was not a required pin!

A piece of single-sided PC board attaches to the 4 supports at the corners with machine screws (see above) and serves as a cover for the receiver. 3 rubber feet on the cover allow the receiver to be used on any surface.

Not much at the back. Just my signature and the date of production of this high performance receiver.

The receiver circuit is a slightly modified version of the application circuit for the TEA5711 AM/FM stereo receiver IC.