I've just finished assembly of the XV432 kit, interfaced to a K3, and ran into two issues during alignment in Part VI, Filter Alignment.
First, during CW key-down, the voltage at TP5 peaks immediately, then slowly drops off until it is a volt or more lower than peak. Immediately re-keying gets a somewhat higher voltage than at un-key, but not at the peak. Letting it sit a minute or two, then re-keying, gets the original peak voltage back. Output power does the same fade. Second, the 28 MHz filters don't seem to be aligning properly. I've set the cans at the set-points in the manual, but L15 and L16 seem to peak with the slugs out of the cans. L17 appears to peak ok, and the 432 filters both seem to peak fine. At the best point of alignment, I am getting less than 7 volts at TP5, vs, 10 required for full output. I've checked the K3 output, and the BNC cables, both are fine. The input section of the XV is easily able to overdrive the input to the 28 MHz filters, as evidenced by D10 and D11 lighting up at roughly half setting on the input attenuator. Max output from the PA is around 15 watts without lighting up D10 and D11. I've pulled and checked the five caps around the filters, all are within tolerance. Oscillator alignment was fine, 3v at TP1. I've tried re-aligning these three cans several times, including bottoming out the slugs and working back up, with no change. I'm on the air with it at the moment, and it seems to be working other than the low power output. Any thoughts? Don W3MW w...@earthlink.net ______________________________________________________________ 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
