Debugging and Assembly of patch miniature FM Radio

1.Debugging

1) Visual inspection of all components after completion of welding components: number of model specifications, installation position, direction or not in accordance with drawings.

Solder joint inspection: whether or not there are virtual welding leakage welding, bridge, spatter and other defect.

2) measuring the current of the whole machine

After checking, weld the power cord to the battery chip.

Install a human battery when the potentiometer switch is disconnected.

3) insert headphones.

Use multimeter 200mA (digital multimeter) or 50mA block (pointer multimeter) to measure power at both ends of the switch stream, note the polarity of the pointer when using the pointer table.

The normal current should be 7-30 Ma (related to the supply voltage) and the LED should be lit normally

4) search radio broadcasts

More than 35 meters of people belong to the wear should be checked in the circuit,If the overall current is in the normal range, press S,switchboard switch search station broadcast.

The installation is correct, the welding is reliable, and there is no need to adjust any part of the radio broadcasts are available face. As long as the components are of good quality.

If the broadcast is not received, the circuit should be carefully checked.In particular, check whether there are false installation of virtual welding and other defects.

5) modulation and reception band

The modulation and reception band is to cover the frequency range of the whole FM broadcast(The frequency ranges from 87 to 108 MHz). Because the radio now uses high-performance integrated circuits and optimized peripheral circuits,

When the performance of components is good, the satisfactory results can be achieved by simple debugging method. This internship product can the receiving frequency band is adjusted by the method of actual listening to the radio station.

During commissioning, you can find a local FM station with the lowest lead rate , and change it appropriately.

The turn spacing of  makes it possible to receive this radio station after pressing the reset key for the first time and then the second press of the SCANSU button. Due to C08S integration becomes high, if the components can be taught to receive the lowest enough radio station can repeat the regulation segment, so you can no longer high and check only (can be checked with a finished FL radio).

6) tuning sensitivity

The sensitivity of  machine is controlled by electricity components decide that.