Be careful if it's a K2/100. Probe ratings decrease with frequency, and the voltage applied to the usual scope probe with 100w going into a 50-ohm load at 28 mHz will blow the 10x attenuator in probe. I don't need to tell you how I know this!
On 4/8/2011 4:15 PM, Don Wilhelm wrote: > John, > > I have to condition my answer on this one because I do not know what kind of > 'scope > you have available. > > If it has a sufficiently high frequency response (3 times the frequency of > the RF to be > measured), and it has a 10X probe with it, then the procedure is easy - just > connect > the 10X probe across your dummy load. If your dummy load does not have easy > access to > connect the 'scope probe, use a Tee adapter at the dummy load end to gain > access to > the center conductor. > > If you do not have a modern 'scope with adequate frequency response, contact > me > off-list and I may be able to dredge some old information out to enable you > to do the > same thing - it is somewhere in my ole references. > > CW: Set the sweep rate to something slow matching your keying rate (key the > TX with a > string of dots), and observe the RF waveform. If it has sharp transitions, > that is an > indicator of potential keyclicks. Look at the 'scope traces shown in the > Elecraft K2 > Keying Waveform Mod instructions for an example of what to look for. > > For SSB: Set up about the same as for CW (the sweep rate will be at an audio > rate). > You will have to review some of the waveforms in the ARRL Handbook to see > what clipping > looks like before being able to judge the waveforms. For amplitude, compare > the peak > of the audio wave to what is obtained in CW mode - and that level will > represent your > PEP. > > Note that you will not actually be able to observe splatter with the 'scope, > that takes > a Spectrum Analyzer - if the waveform shows clipping (abrupt transitions at > the peaks), > that is an indicator that splatter is occurring, but the 'scope will not show > it > directly. > > 73, Don W3FPR > > On 4/8/2011 3:06 PM, John Cooper wrote: >> How would I use a scope to monitor key clicks on cw, and the waveform on >> ssb? Also >> anything else I can do with a scope too? This is in reference to a K2 IE >> where do >> the probes go and so forth. Off list is fine too. Couldn’t find any >> definitive >> answer in the archives. >> >> >> WT5Y -- Vic, K2VCO Fresno CA http://www.qsl.net/k2vco/ ______________________________________________________________ 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
