829 Amp Build

 This is a small RF amp for use with QRP, small SDR etc rigs to bring the low 2-5 watt output up to the 100w+ range. By swamping the input with a 100 ohm resistor, installing a tapped tank, tuned inputs are avoided and easy multiband operation is achieved. 

I designed this one as a monoband amp, and set it up on 29.000 mhz on the bench. I added an RCA port on the rear to key down stream QRO amps for full legal limit operation with a QRP rig. Here's a few vids and pics...

Finished pics...

It requires very little ventilation, so I fabricated a perforated rear panel.

A look inside frome the rear...

The project begins...

I love this wrinklefinish...

Spray it on wet, and wait...

Testing the Filament current...

Opening the neon lamps and installing incandescent bulbs...

Perforated base and tube sockets installed...

Transformer mockup...

Wiring begins...

RF sensing circuit built...

3-wire safety cord installed...

Chassis clearance for switches...

RCA port to key QRO amp...

Setting idle current...

Sweeping the input and outputs circuits...

Nearing completion...

Choosing from misc coil stock :-)

Cutting rear ventilation panel from stainless steel...

Packing for transport...

Tuned monoband input to allow for very low drive levels...