Category: DIY

Bench AF Amplifier 0

Bench AF Amplifier. Schematic Diagram.

The circuit… This circuit consists of just a few discrete components and one common IC amplifier – the LM380N. It’s simple, cheap, quick to build and works well. I built mine in a steel,...

5 element quad for 2m band 0

5 element quad for 2m band

Boom Length – 1651 mm Distance between: Between Distance, mm R – V 432 V – D1 330 D1 – D2 406 D2 – D3 483 Dimenson of elements: Side, mm Diagonal, mm Perimeter,...

QRP Dummy Antenna 0

QRP Dummy Antenna

I needed a small dummy antenna for testing my Elecraft K2. It was to be small and capable of being used into the VHF range. It had to have a BNC connector, and it...

Variable Power Supply Unit. 0

Variable Power Supply Unit. DIY.

This little circuit is a copy of a design which was built around twenty years ago. The heart of the unit is based around a 723 regulator chip. It has variable voltage and current...

6m to10m converter 0

6m to 10m converter

This circuit is based around mixer/oscillator IC2. A 50mHz signal is fed to pin1 input of IC2 and mixed with the local oscillator injected at pin7. The resultant output is the antenna frequency minus...

Tilt Tower 0

A 40′ Tilt-Tower for VHF Beams

This is the first tower I built. After moving here, the idea occurred to me that trees can save a lot of money and work when it comes to towers. Trees are already firmly...