Dick, That is probably normal - you are hearing the internal receiver noise. It should be at a fairly low level - you said it was, but I can't relate to your perception of just how low or loud that may be. If you are using very sensitive headphones, it will be apparent at a lower setting of the AF Gain than would be heard with less sensitive headphones. All I can say for certain is that when I am working on a K2, I normally plug my computer Line-in cable into the headphone jack (mainly so I can see the trace on Spectrogram), and as a result I hear the K2 audio in the computer speakers - I can usually hear the internal receiver white noise 'hiss' with the AF Gain set somewhere near the 8 o'clock position - but I can change that point easily by adjusting the gain control on th epowered computer speakers.
You said you had AGC off - and yes AGC can influence how loud the internal noise appears to be. In the K2 (after SN 3000), there is an AGC Threshold pot on the Control Board, and the most sensitive setting for that control is at the point where activating the AGC does not *substantially* reduce that internal receiver noise. It will reduce the internal noise a bit, and that exact threshold setting will vary from K2 to K2 - the initial 3.80 volt setting is not a "one size fits all" setting - the manual alludes to the fact that it could be refined by saying "but it can be adjusted later to suite the operator." The manual does not further explain how to determine that setting. Be AWARE - the AGC Threshold must be set before adjusting the S-meter, and the S-meter must be calibrated after changing the Threshold. A Threshold setting below about 3.65 volts may not allow one to adjust the S-meter properly. 73, Don W3FPR richard gilley wrote: > With so much talk on the K3 noise, AGC etc I thought I would ask if > the following is normal on a K2. Or do I have an issue with my build > 6732. > This K2 has the KSUB SSB and KPA100 additions. > With only battery power and ear phone connected; AGC off: AF fully > clockwise; RF gain fully ccw; cw mode; fltr settings 200,400, or 700. > any band, I hear a definite constant, fairly low level, hash. > > With RF gail fully clockwise and AF gain fully ccw, no hash is heard > until AF gain is advanced from 7 o'clock to about 8 o'clock. > > Would this be considered normal or do I have another issue to look into? > > Best regards > Dick AD1G > ______________________________________________________________ > 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 > ------------------------------------------------------------------------ > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 9.0.733 / Virus Database: 271.1.1/2665 - Release Date: 02/03/10 > 03:09:00 > > ______________________________________________________________ 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
