[Elecraft] K3 dumb Q about PPM, less dumb one about NB

[Jim Wiley]

I suspect the original writer is being confused with the correct 
designation of the units involved in the query.  One PPM  is equivalent 
to 1 hertz per megahertz.  Stability specifications for amateur radio 
equipment are frequently stated in reference to 1 megahertz.  In such a 
case, 1 PPM at 10 MHz works out to 10 hertz.   


The units described in the original question are stated as mHz, 
(millihertz), or 1/1000 of a hertz.  Megahertz, or 1 million hertz,  is 
more correctly annotated as MHz.   A value stated in millihertz is 
uncommon in amateur radio circles.  It is perfectly true that a 
millihertz is a valid unit, it's just not often seen.  And, as far as I 
know, has never been used, either in an advertisement or a user manual, 
to express the basic frequency stability of a piece of ham gear.


- Jim, KL7CC


David Woolley wrote:
> 1ppm relative to 10mHz is 10nHz (unless you are a PC salesman).  There 
> are aspects of amateur radio in which mHz are a useful unit.
>
> lstavenhagen wrote:
>   
>> Just refreshing my 6th grade education here: 1 ppm variation at 10 mhz would
>> be +/- 10 hz correct? I calibrated my K3 ref. osc. again yesterday (against
>>     
>
>
>
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