[R-390] Measuring Sensitivity

[Bob Camp]

Hi

The GR 1001A must be calibrated different than a "standard" signal  
generator like the URM-25 or an HP 8640B.

Bob


On Mar 17, 2007, at 12:44 PM, Barry wrote:

> 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
>
>
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