Hi Julian I am very glad to see that someone has replyied to my email.
I have LINE_OUT= "nor 019" If I go down to 002 I need to rise gain at the sound card, and the intermods are the same. http://ea1abz.ure.es/spurs.jpeg This spurs seem to produce only if both test signals are close, closer than 50 Hz and in DATA/CW mode, not USB/LSB. Do not think that this spurs will cause a problem in real life operation. Just curious about the DATA/CW vs LSB/USB diferences found. Perhaps a "pile up blur" will occur when many CW stations are very close, who knows ( do not know how to say it in english) Thanks for your suggestions! 73, Ramiro, EA1ABZ. Julian, G4ILO escribió: > What output are you taking the audio from to plot these results? The line > output signal goes through an isolating transformer. I think this saturates > at quite a low audio level introducing non-linearity. You need to turn LIN > OUT down to 2 or as low as you can get. > > I haven't done the test you did, but if I look at a CW signal with a narrow > filter selected I can see a ghost image of the signal on the waterfall at > twice the audio frequency, well outside the IF passband. So I think the > problem (if indeed it is a problem - nothing is perfect) is within the audio > stages and particularly the line output. > > > Ramiro Aceves wrote: >> Hello K3 fans >> >> I am a bit stranged and frustrated cause nobody has answered a single >> word to my email "K3 RX spurs" posted on november the 20th. No comments, >> no ideas.... >> After some tests I have concluded that the spurs are 3rd order >> intermodulation products. They only occur in DATA or CW. >> ¿Can anyone please, try to reproduce those products in your K3/P3 or >> K3/computer combination?. >> >> "DATA A" mode: Cristal filter= 2.7KHz, SHIFT=1.5 KHz, WIDTH= 2.7 kHz >> Tune some steady carrier in shortwave. Tune the signal to place a >> beautiful 1000 Hz on the waterfall >> Tune your signal generator 10 Hz more than the broadcast carrier >> frequency to get an audio signal 10 Hz over the 1000 Hz signal. Adjust >> generator strenght to be similar to the broadcast carrier. >> >> You will see strong beautiful 3rd order products on 1020 and 990 Hz. >> Swith to USB--> much more weaker 3rd order products or inexistent. >> >> http://ea1abz.ure.es/3erd-order.jpeg >> >> That is my K3 behaviour. Just want to know if my K3 is ok or not. >> >> Many thanks. I appreciate your effort in doing this test for me. >> >> 73, Ramiro, EA4NZ. >> >> PD: Volume at the speaker is zero to avoid vibrations inside the K3 >> case. >> >> > > > ----- > Julian, G4ILO. K2 #392 K3 #222. > * G4ILO's Shack - http://www.g4ilo.com > * KComm - http://www.g4ilo.com/kcomm.html > * KTune - http://www.g4ilo.com/ktune.html > ______________________________________________________________ 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
