Band 2 Preamplifier Circuit

This is a VHF amplifier for the Band 2 Radio Spectrum tuning approximately 88 – 108 Mhz.

click to enlarge the schematic

The circuit uses two 2N3819 FET’s in cascode configuration. The lower FET operates in common source mode, while the upper FET, operates in common gate, realising full high frequency gain. The bottom FET is tunable allowing a peak for a particular station. Coil details follow:

L1 4 turns of 18swg air spaced with a 1cm diameter, the tap is one turn up from earth end…
L2 4 turns of 18swg air spaced with 1 cm diameter. The coupling coil is 1 turn interwound from the supply end. Enamel coated wire must be used.

Circuit : Andy Collinson zen22142.zen.co.uk

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This entry was posted on Thursday, November 13th, 2008 at 5:51 pm and is filed under Frequency, Schematics, Sound/Radio Circuits, Transmitter/Receiver. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.