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 >> > > > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
