I've had a few exchanges with support on this, but as Covid-19 is imposing some new burdens on the shop, I thought I might ask the larger community for input as well.
I've been troubleshooting seemingly anomalous power consumption when transmitting. My K3S pulls way more current on 20m than on 40m for the same input signal and output power. After some experimentation, I found that the input current is related to whether the KAT3A is engaged, and which values of C and L are selected. The lowest power consumption comes from the highest value for C and the lowest value for L, and the highest power consumption comes from the lowest C and highest L. Here's a chart of what I found going into a dummy load, manually setting C and L values: min C/max L max C/min L bypass not-inst 40m, 12w 3.55A 2.23A 3.4A 3.3A 20m, 12w 3.70A 1.99A 3.1A 3.0A 40m, 13w 11.5A 4.65A 7.3A 7.2A 20m, 13w 15A 5.63A 6.9A 6.8A If that chart doesn't render well on the list, here's a screen shot of it: https://imgur.com/GF4IUIy (This was transmitting a 1500Hz tone, SSB at almost 100% modulation with 14v supplied, and is the value reported by the K3s, though my ammeter reports a similar value. I get similar results with FT8 going into an actual antenna instead of a dummy load.) So I guess the question is this: is it expected to see such a large variance in power consumption for the same output power based on the values of C and L for the KAT3A? Nick -- *N6OL* Saying something doesn't make it true. Belief in something doesn't make it real. And if you have to lie to support a position, that position is not worth supporting. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
