[R-390] Measuring Sensitivity

[Barry]

I measured (as best as I could) the output of this General Radio 1001A.  Using the lowest frequency and the highest output level, when terminated into 50 ohms, it measured 1/2 the value indicated on the generator.  100mV measured as 50mV, etc.

This generator is a bit odd in that on all but the highest setting, its output impedence is 10 ohms so you use a 40-ohm series resistor and then terminate the other end of the coax into 50 ohms.  As far as the resistors I used, they were whatever were available at the parts place.  I think they are metal film, but not sure about that.

Barry - N4BUQ

  Hi


  A normal correctly calibrated modern generator puts out twice the indicated voltage into an open circuit. It puts out it's indicated voltage when hooked to a 50 ohm load. 


  The excitement with a one ohm pad is the small amount of series inductance on the one ohm that can mess things up. A good thin film chip resistor is a good idea there. Digikey sells them pretty cheap.


  Bob