Mike, That mod to the K2 (which has been incorporated into the new K2s) is simply a limiter. If the signal level at the input to the IF amplifier ever increases to the point where the diodes clip the signal, then distortion will occur. The clippping distortion may not be noticed on CW, but it certainly will distort SSB and data signals.
There is a mod for the K3 to change to a larger choke in the AF amplifier. If that change is not installed, distortion can occur in the AF amp itself. But all in all, Jim Brown is correct - a large signal like what was reported is certain to cause activation of the COR at the K3 input (input protection) and distortion is to be expected in situations like that. It is also likely that the K3 Hardware AGC is maxed out and can lower the gain no more with the resulting of overload of the ADC. Without making measurements, it is difficult to say just where the overload point(s) might have been, but it is clear that a 100 watt signal ON FREQUENCY with antennas close to each other is certain to create overload and the distortion is a natural 'happening' under such overload conditions -- in other words, the K3 dynamic range (as good as it is) was exceeded - everything has its limits. 73, Don W3FPR Mike Harris wrote: > Hi, > > Just been looking through my archives. I remembered that there was a > simple mod to the K2 to overcome audio distortion in an extreme overload > environment, I installed it on my K2 and it was totally immune to > co-channel audio distortion when my very near neighbour VP8LP transmitted: > > "K2 - Improved Handling of Extremely strong (and nearby) Signals". > > Maybe the K3 architecture offers similar opportunities. > > Regards, > > Mike VP8NO > > ______________________________________________________________ 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
