W2 Wattmeter 440 band accuracy?
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W2 Wattmeter 440 band accuracy?
 
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I just purchased a new Yaesu digital handheld and the power level on the
440 band is low (2.8 v 5.0 Watts), and was wondering if I can trust the W2's accuracy? Another mobile higher powered transceiver also reads low on all power levels on the 440 band. I built the kit version of the W2 and have the VHF/UHF coupler.... Why is there a +/- calibration button on the PC interface if the unit is calibrated properly? I can send my HT back to be tested and exchanged if it isn't making specs but don't want to be told that my wattmeter reading was inaccurate! 73's Michael n2zdb ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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That would depend on what kind of digital you are talking about. I don't
think the W2 reads instantaneous peak power. That usually takes special circuitry to do . Hint: a digital slug for a bird 43 wattmeter costs way more than the meter does. Analog meters will not read properly in a digital environment. Try the radio in analog mode. Phil, wd8qwr ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: W2 Wattmeter 440 band accuracy?
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In reply to this post by Elecraft mailing list
Measurement is in analog mode.....should have made that clear or not even
mentioned a digital radio! Michael ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: W2 Wattmeter 440 band accuracy?
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The only way to get the answer you wish is to compare it to a bench
standard like a bird watt meter. Beyond that you are just guessing. Sorry Mike va3mw On Sun, Jul 30, 2017 at 11:18 AM, Michael via Elecraft < [hidden email]> wrote: > Measurement is in analog mode.....should have made that clear or not even > mentioned a digital radio! > > Michael > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: W2 Wattmeter 440 band accuracy?
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In reply to this post by Elecraft mailing list
OK so I am trying to measure around 5 Watts or so on the W2's 20 Watt
scale. The spec's for the W2 directional couplers are listed at 0.5 dB accuracy. Is this anywhere or just at full scale? How much could it be off at only 25% of full scale? Trying to decide if the 2.8 Watts I am reading at 440 MHz on high power is too low with a spec of 5 Watts output! If it is I can send it back to the place of purchase to be checked and exchanged if necessary. There seems to be no problem on the 2 Meter band at only 25 % of scale (5 Watts) reading....just on 440. Michael n2zdb In a message dated 07/30/2017 12:36:49 P.M. Eastern Daylight Time, [hidden email] writes: The accuracy of a Bird Model 43 is +/- 5% of full scale. The meter scale is not linear and produces the best read accuracy in the bottom portion of the meter's scale. There are numerous watt meters on the market today that are more accurate. FWIW 73! Ken Kopp - K0PP ---------------------------------------------------------------------------- -------------------------- On Sun, Jul 30, 2017 at 9:23 AM, Michael Walker <[hidden email]> wrote: The only way to get the answer you wish is to compare it to a bench standard like a bird watt meter. Beyond that you are just guessing. Sorry Mike va3mw On Sun, Jul 30, 2017 at 11:18 AM, Michael via Elecraft < [hidden email]> wrote: > Measurement is in analog mode.....should have made that clear or not even > mentioned a digital radio! > > Michael ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: W2 Wattmeter 440 band accuracy?
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Michael,
In general, digital wattmeters have the same accuracy at any point on the scale - unlike analog wattmeters for which the accuracy is stated as a percentage of the full scale reading. On a 20 watt scale, a 25% error would be up to 4 watts! You might want to look at the specs for that 440 MHz transmitter as well. If it 2.6 dB or so, getting 2.8 watts out for a 5 watt setting may be what you can expect. 73, Don W3FPR On 7/30/2017 4:59 PM, Michael via Elecraft wrote: > OK so I am trying to measure around 5 Watts or so on the W2's 20 Watt > scale. The spec's for the W2 directional couplers are listed at 0.5 dB > accuracy. Is this anywhere or just at full scale? How much could it be off at > only 25% of full scale? > > Trying to decide if the 2.8 Watts I am reading at 440 MHz on high power is > too low with a spec of 5 Watts output! If it is I can send it back to the > place of purchase to be checked and exchanged if necessary. > > There seems to be no problem on the 2 Meter band at only 25 % of scale (5 > Watts) reading....just on 440. > > Michael > n2zdb > > > > > > > In a message dated 07/30/2017 12:36:49 P.M. Eastern Daylight Time, > [hidden email] writes: > > > > > The accuracy of a Bird Model 43 is +/- 5% of full scale. The meter scale > is not > linear and produces the best read accuracy in the bottom portion of the > meter's > scale. > > > There are numerous watt meters on the market today that are more accurate. > > > > FWIW 73! > > > Ken Kopp - K0PP > > ---------------------------------------------------------------------------- > -------------------------- > On Sun, Jul 30, 2017 at 9:23 AM, Michael Walker <[hidden email]> > wrote: > > The only way to get the answer you wish is to compare it to a bench > standard like a bird watt meter. > > Beyond that you are just guessing. Sorry > > Mike va3mw > > > On Sun, Jul 30, 2017 at 11:18 AM, Michael via Elecraft < > [hidden email]> wrote: > >> Measurement is in analog mode.....should have made that clear or not even >> mentioned a digital radio! >> >> Michael > > > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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