It's not as elegant as having an automatic circuit handle the issue, but one way to reduce the amount of ALC and associated "overshoot" on 40 is to reduce the audio to the rig. Switch in the audio attenuator at the MENU or otherwise reduce the audio to the mic jack until you are getting just one bar of ALC flickering, or no ALC bar at all, on voice peaks.
Ron AC7AC -----Original Message----- G'day, I have now done the resistor mod to no effect and will probably revert 'cos I don't like how I had to add the 1K0 in series with the base of Q1. Driving the K2/100 into a dummy load and just using the bar led display I see the following: Set requested power to 30W. Mode SSB. SSbA = 2, SSbC = 2-1, Mic Kenwood MC-43C. Mic jack grounding mod done. On 80M I see up to three bars ALC. Set to RF, regular peaks of 50W. On 40M I see up to seven bars of ALC. Set to RF, regular peaks of 50W and occasional peaks of 70W or more. On 30M I see up to six bars of ALC. Set to RF, regular peaks of 50W, occasional peaks to 60W. On 20M I see one bar of ALC. Set to RF, regular peaks to 40W. 18M - 10M, one bar of ALC. Set to RF, peaks to 40W. Set mode to CW. Request 30W. All bands power peaks to 30W, no overshoot. I dropped the requested power to 5W thus switching out the KPA100 and similar SSB overshoot problems presented. Conclusion, in it's present state my K2/100 is unusable on 40M SSB with an amp. If this is a common problem then it looks like the KSB2 is in need of some serious work unless the excess TX path gain in the 7 - 10MHz spectrum can be tamed. Maybe it also gives a clue to those reasonably frequent Hi Current warnings when running barefoot at 100W Regards, Mike VP8NO | Thanks Steve.. I was hoping there was something I could do. Do you (or | anyone) have the details of the necessary resistor changes? | | Don K7FJ | | | | ----- Original Message ----- | From: "Steve Kavanagh" <[EMAIL PROTECTED]> | To: <Elecraft@mailman.qth.net> | Sent: Wednesday, November 01, 2006 5:55 AM | Subject: Re: [Elecraft] SSB output overshoot | | | >I think Don's observations sound like the problem I | > and a few others have had. See, for example the | > symptoms described here: | > | > http://www.ac6rm.net/mailarchive/html/elecraft-list/2005-03/msg00676.html | > | > http://www.ac6rm.net/mailarchive/html/elecraft-list/2005-12/msg00408.html | > | > These two, at least, were due to the KSB2 ALC circuit having | > insufficient attenuation range to control the output of K2/100's | > which have above-average overall transmit gain on the lower bands. | > The fix involves adding a resistor and changing another in the KSB2. | > Gary Surrency at Elecraft was able to provide me the | > necessary details. | > | > But Mike's problem sounds much less severe. It might | > be a marginal case of this effect, I suppose. | > | > 73, | > Steve VE3SMA _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
