RX1 Noise Bridge - VK1OD build

The following pics document my build of a VK3AQZ RX1 Noisebridge.

Fig 1:

Fig 2:

Above, constructed with N jacks for the receiver and unknown port, and jack for external DC supply.

Fig 3:

Above, a view of the interior from the front. The jack for external DC can be seen at the rear of the original battery compartment.

Fig 4:

Above, a view of the interior from the rear. A 100mA Polyswitch was added to the switch board to provide overcurrent protection, mainly for the external supply / battery.

Fig 5:

Above, the waveform at the collector of a multivibrator transistor, and the modulated noise into the bridge (loaded). The modulated noise is quite different to that shown in the manual, partly due to the fact this is a single trace captured on a DSO.



Version Date Description
1.01 08/04/2011 Initial.