KC0WOX Bitx Test Bench

Testing is easy with this equipment. It's old but there was a time when it was state-of-the-art. It's still very good for this application.

Top Right - HP5335a Frequency Counter
Below it - HP8552a/8553b/140 spectrum analyzer
Below that - HP3325a Function Generator
Left of that - HP8601a Sweep Generator
Left of that - Current limited 2 amp power supply
Bottom left _ Tektronix 7904 oscilloscope

The board is set up as below.

The board clamps into a rotating holder that allows very easy access to the board bottom. The tuning capacitor is clamped into the panavise at the right of the board. The microphone has plug connectors for the PTT and the Mike audio lines. This can be unplugged and replaced with a PTT switch and a audio generator for level testing and the actual board alignment. There is a plug on piece of coax terminated in a BNC connector to allow connection of a dummy load or antenna. You can see the scope probe connected to the antenna connector to allow setting the rf levels. The board is completely functional in this configuration. In fact, I just worked Hawaii from Denver, Co with this. That's why the microphone is still connected.

From the configuration above to this is about a 90 second change. There is no solder connections required as the board is equipped with molex connectors.

Here it is all together and ready for the top to be added and made permanent. Another successful Bitx20a kit hits the airwaves.