James, You are beginning to venture on a losing battle!! What used to be the 'old reliable' Bird watt meters had an accuracy of +/- 5%. Typical ham watt meters, especially the ones that use diodes to produce forward and reflected power, typically never mention an accuracy specification. You will also notice that for a given constant load, the same watt meter will change the SWR reading as you change your power. As you know, SWR is not a function of RF output power! 4.5 watts is 10% of 5 watts and if you change watt meters you are going to get a completely different answer. Very few watt meters are calibrated to any standard and if they are, they most likely are not recalibrated once a year.
The only solution to the answer you are seeking is $$$$$$$$$$! 'Close enough' will have to do with watt meters. Tom - W4BQF -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of James Sarte Sent: Friday, October 29, 2010 5:18 PM To: The Smiths Cc: Elecraft Reflector Subject: Re: [Elecraft] K3: LPA power level accuracy? No, wasn't aware of that. It's been a while since I've delved into the K3's menus. Do you know what that option is called, or where to find it in the manual? Also, just to make sure I'm understanding you correctly - do you mean to suggest that if the K3's watt meter reads 5W, but actual output power is 4.5W, you can adjust output power to match the K3's meter? As it is, the K3's meter and LPA power settings do not match the readings displayed on my outboard analog and digital forward power meters. When the LPA is in use, displayed power is always a .5 to 1 watt lower on the external meters. 73 de James K2QI On Fri, Oct 29, 2010 at 5:04 PM, The Smiths <[email protected]> wrote: > There's also an adjustment that you can make manually to move the power up > or down from what the meter is reflecting on the K3, have you tried that > too? > > > Date: Fri, 29 Oct 2010 17:00:21 -0400 > > From: [email protected] > > To: [email protected] > > Subject: [Elecraft] K3: LPA power level accuracy? > > > > > Hello fellow Elecrafters, > > > > Quick question - I've noticed that when using the LPA, output power is > > always slightly off compared to the reading given off by two fairly > accurate > > meters. For example, a constant carrier output of 5 watts always reads > > about a half-watt less on the external meters. The output power from the > > KPA3 however has always been on the dot - 80 watts drive reads 80 on the > > meter, 100 watts output reads 100W on the meter, etc. etc. > > > > I'm not really concerned, but was wondering if this was typical? I've > > calibrated several times in the past using the K3 utility, but the > results > > are usually the same. > > > > -- > > 73 de James K2QI > > President UNARC/4U1UN > > ______________________________________________________________ > > 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 > -- 73 de James K2QI President UNARC/4U1UN ______________________________________________________________ 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
