John, A long time ago, there were pops and thumps with keying in a few K2s having the KDSP2 and KPA100 options. It was coming from the KPA100 T/R switch, and several changed capacitor values in the KPA100 to combat it.
Check your KPA100 - if it has red toroid cores at L15 and L16, then adding KPA100UPKT would be the first order of business. I have not seen mention of a K2 parallel to that K1 mod - you could try it, but you would need two caps and two resistors - connect to the drain of Control Board Q7 and Q8. 73, Don W3FPR On 4/15/2012 12:56 AM, VK7JB wrote: > Hello Group, > > I've been using my K2/100 on CW a bit lately and have noticed that there are > low frequency thumps/pops on the receive audio at the rx to tx transition - > ie onset of keying (key closure). They are most noticable if the noise > floor is high or if there are other signals in the receiver passband. If I > wind the RF gain right back or operate on a really quiet band and the > artefacts disappear. > > They don't relate to the DSP (they occur even when DSP is bypassed), to the > state of the 8R Hold parameter or to the presence or absence of transmitted > RF (the artefacts are present also in TEST mode). > > ______________________________________________________________ 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
