Mike. but 5% of full scale for a 100 watt slug is 5 watts. That is exactly the point being made. The error is a percentage of the Full scale reading, and not a percentage of the actual reading.
A 250 watt slug can have an error of 37.5 watts - whether the power reading is at 10 watts or 50 watts al that can be concluded it that there is some power output - the number displayed by the meter cannot be relied on if the power is significantly lower than the power ratting of the slug . 73, Don W3FPR On 12/9/2011 7:11 PM, Mike wrote: > 5% of 50 watts is not 5 watts. > > 73, Mike > > On 12/9/2011 10:32 AM, Eugene Balinski wrote: >>> From what I understand, the meter is rated at 5% of the >> **full scale** rating according to Bird. Full scale >> rating, is the rating on the slug. >> >> That would mean that for a meter with a 100W slug, your >> accuracy is +/- 5W (5%). So, if your wattmeter is reading >> 50W, the actual RF power could actually be 45 or 55 W.... >> >> 73 >> K1NR >> >> >> On Fri, 09 Dec 2011 09:08:55 -0500 >> Mike<[email protected]> wrote: >>> Wait. >>> >>> Using a 100W slug, if you get a reading of 100 watts, the >>> real power would be between >>> 95 and 105 watts, right? >>> If you get a reading of 50 watts the real power would >>> fall in a range of less than 45 >>> to 55 watts? >>> >>> Not if the 5% at full scale is the best accuracy. Or did >>> I misunderstand what you said? >>> >>> 73, Mike NF4L >>> >>> >>> On 12/8/2011 11:59 PM, Eugene Balinski wrote: >>>> The accuracy of Bird elements is typically +/- 5% of >>> the >>>> full scale value. For a 100 W Slug, that is +/- 5 >>> Watts. >>>> So theoretically speaking, with 5W in, and 0 >>> registered >>>> on the meter, the meter is still within its rated >>> accuracy. >>>> Additionally on the model 43 meter, there is meter >>> scale >>>> end compression. To get the most accurate reading, one >>>> would want to have the 5W reading at the middle of the >>>> meter range, which means that one would want a 10W >>> slug. >>>> Unfortunately I do not believe that Bird makes a 10W >>> HF >>>> slug any more. Perhaps they need an Elecraft W2 ?? >>>> >>>> 73 >>>> K1NR >>>> >>>> >>>> On Thu, 8 Dec 2011 16:47:27 -0600 >>>> Nate Bargmann<[email protected]> wrote: >>>>>> From my experience, trying to measure 5W with a 100W >>>>> element leads to >>>>> very inaccurate readings. The Bird is most accurate >>> when >>>>> the reading is >>>>> as near to full scale as possible. That means a 5W HF >>>>> element (is that >>>>> even available?) would be ideal provided no more than >>> 5W >>>>> is put through >>>>> the meter. A 10W element would be less accurate but >>>>> provide a safety >>>>> margin for the meter. Even better would be to have >>> both >>>>> elements and >>>>> use the 10W one to get in the ballpark and the 5W one >>> for >>>>> a final check. >>>>> >>>>> 73, de Nate N0NB>> >>>>> >>>>> -- >>>>> >>>>> "The optimist proclaims that we live in the best of >>> all >>>>> possible worlds. The pessimist fears this is true." >>>>> >>>>> Ham radio, Linux, bikes, and more: http://www.n0nb.us >>>>> >>> >> ______________________________________________________________ >>> 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 >> --------------------------------------------------------------------- >> Web mail provided by NuNet, Inc. The Premier National provider. >> http://www.nni.com/ >> > > ______________________________________________________________ > 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 > ______________________________________________________________ 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
