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Receiver Noise Bridge – Pt 4

 

Receiver Noise Bridge – Pt 4

Once the electrical build and calibration were complete, I used Visio and Photoshop to create some graphics for the control panel.  I also made a graph to convert what the dials say to actual values on the HF and 6-meter Ham bands.


The front panel has a resistance control in the top left, scaled from 0 to 287 ohms.  The reactance scale is calibrated for ohms of reactance at 10 mc.  The graph is used to convert this reading to other bands.  The reactance scale is from 67 inductive to 1500 ohms capacitive at 10 mc.


The lid contains a graph for conversion of readings to other ham bands.


And here is the box with the lid closed…



Migrated Comments:

2 Responses to “Receiver Noise Bridge – Pt 4”

  1. Peter Says:

    Where’s u get the schematic, Thanks

  2. wb0smx Says:

    It’s been a long time since I built that Peter. Looking back through my notes, it appears that I based the design on the 1987 ARRL Handbook entry for “Noise Bridge for 160 through 10 meters” in chapter 25. That has the single variable capacitor, the 555 timer used to modulate the zener diode noise source, and the NPN transistor aplifiers for the noise source.

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