[Elecraft] K3 Watt Meter Calibration Question

[Wes Stewart]

Not necessarily.  For example, an HP8970 Noise Figure Meter reads to 0.01 dB, 
yet uncertainty (for just instrument error) is +/- 0.1 dB.  In the days of yore, 
LNAs were typically highly mismatched at the input and this added further 
uncertainty.  I once measured a friend's homebrew 1296 MHz preamp NF at 0.7 dB. 
I calculated the uncertainty at +/- 0.7 dB!

I got a chuckle when HP gave an '8970 to the ARRL lab and they did a test on a 
preamp (ARR if memory serves) and gave the NF to two decimal places.

Wes  N7WS

On 6/6/2016 4:11 AM, brian wrote:
>
> There are some exceptions to this rule.  HP equipment (at least the older 
> stuff) would only digitally display the number of truly believable significant 
> digits.  For example, their counters would not display all available digits 
> but just those one can real.  So there are exceptions to all rules of thumb.
>
> One has to know their measuring gear characteristics to know what to believe.
>
> 73 de Brian/K3KO