Antenna feed impedance under 50R? Take some measurements with a cheap VNA On Mon, 12 Oct 2020 at 01:55, Bill Coleman <[email protected]> wrote:
> Don, > > I finally got around to running my K3 into a dummy load. > > I had no problem running 100w or even 110w with a dummy load. Current draw > from the power supply was 22 A and 23 A, respectively, on the K3 display. > No HI CUR indications. > > External wattmeter validates the output. > > I was getting the HI CUR indication on a trap 30/17/12m inverted V. I had > to take it down, and now I’m using a trap 80/40/20m dipole through the > tuner. No HI CUR indication on that antenna, either. > > Even though I have current baluns on both antennas, I’m thinking that my > HI CUR problem may be related to RF feedback in the shack. > > Do you concur? > > I’m in the process of a number of shack improvements, including antenna > replacements and grounding and bonding, so that might take care of it. > > > On Jan 11, 2020, at 11:29 AM, Don Wilhelm <[email protected]> > wrote: > > > > Bill, > > > > Is this into a dummy load (bypass the ATU or tune the ATU into the dummy > load). > > If it is into an antenna, there are a whole lot of guesses about how the > antenna behaves with higher power levels than your antenna analyzer shows. > So check it with a dummy load to eliminate the possibility that the problem > is in the antenna. > > > > Put an external wattmeter in line with the dummy load to eliminate > questions about the calibration on the K3 wattmeter. > > > > If you can measure the actual current drawn, that would also be helpful. > > > > 73, > > Don W3FPR > > > > On 1/11/2020 11:18 AM, Bill Coleman wrote: > >> Back in early December, I installed two KSYN3As in my K3 SN 7071. > Sometime after that, I noticed that on 12m, I’m seeing a HI CUR indication > when I set the power level to more than about 80-85 watts. The K3 will back > off on the power level, then slowly ramp back up until it hits HI CUR again. > >> I don’t remember seeing this before. After the KSYNC3A install, I ran > the transmit gain calibration at both 5 and 50 watts, as specified in the > instructions. Just in case something went awry, I ran it again. > >> I’m still seeing this problem. What causes HI CUR at 85 watts? The K3 > ought to be able to produce over 110 watts on 12m. > >> I’m not seeing this issue on other bands. > >> No issues with calibration > > Bill Coleman, AA4LR, PP-ASEL Mail: [email protected] > Web: http://boringhamradiopart.blogspot.com > Quote: "Not within a thousand years will man ever fly!" > -- Wilbur Wright, 1901 > > ______________________________________________________________ > 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 > Message delivered to [email protected] ______________________________________________________________ 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 Message delivered to [email protected]
