How to remake 88-108 MHz FM receiver to 120-150 MHz

Conventional VHF receivers for a frequency of 88-108 MHz can be converted to reception frequencies that the receiver microcircuit allows. Usually this is approximately up to 150-160 MHz. This will allow receiving radio amateurs on frequencies of 144-146 MHz, airport or airport reports and other signals

For the conversion, I took a scanning receiver that was widespread about 20 years ago. The microcircuit is SC1088, also known as TDA7088. First, you need to remove the scanning mode in order to tune with a variable capacitor. To do this, unsolder the varicap from the local oscillator coil and solder a variable capacitor in its place. The capacitor is from several pF to 40-50 pF, two terminals are connected to increase the capacity

On the receiver board, you can see two coils. One coil, usually of larger diameter, is the input filter, which passes signals with certain frequencies. The other coil, smaller in diameter, is the heterodyne coil. They need to be unsoldered and replaced with others

Now the new input filter coil contains 4 turns of 0.6 mm diameter wire wound on a 5 mm mandrel. The heterodyne coil contains 4 turns of 0.6 mm wire, but is wound on a 3 mm diameter mandrel. Now the receiver can receive conversations of radio amateurs from different cities. Radio amateurs were received on a 60 cm section of wire at a height of 10 floors