Jim, there are a number of things that can account for the discrepancy: 1) The K3 bargraph registers in 10 watt steps so it's difficult to interpolate the 25 watt level.
2) An SWR report of 1:1 into an antenna does not mean the load is the 50 ohms non-reactive the power meter expects. It's close, but not close enough for a power meter calibration. You need a precision dummy load to compare the power reports. 3) Unless you are spending thousands and thousands of dollars on power measuring equipment (including a precision dummy load), an error or 5% or more is considered extremely accurate. Ten percent or greater is common. 73, Ron AC7AC -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jim Bennett I've been using my K3 #4359 now for several years w/o any issues. Just this past week I acquired an LDG AT-600ProII auto tuner and the matching M-600 analog meter. I calibrated the M-600 per the instructions. What I'm seeing is that the M-600 meter is showing me higher RF output than the K3's bar graph on most bands. As an example, after setting the KAT3 to Bypass, using the AT-600 to bring an antenna to a match (close to 1:1) with 5 watts out of the K3, I turn the K3 power output to 25 watts. A key-down on the K3 shows 25 watts on the K3 bar graph, but the M-600 tells me that the power is about 39-40 watts. It is like this on nearly all the bands, 160-10 meters. On 6 meters, the M-600 reads about 20% LOWER than the K3. I sent an email to LDG and asked them what's up - which is correct - the K3, or the LDG unit? Their response is that the K3 most likely is incorrect, as they calibrate their equipment with an Alpha 4500. That's a tad of an expensive meter, to say the least. Are the LDG folks tweaking me on this, or is that M-600 really more accurate than the RF bar graph on the K3? Jim / W6JHB ______________________________________________________________ ______________________________________________________________ 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
