Thanks Richard, To me that's an indication the DAC stages are indeed maxing out on LF (near DC) content. Either reducing the low EQ or shifting the passband up alleviates this.
Some sort of DC blocking between DSP and DAC could help. (also for the PB shift "clicking" effects) 73' Paul PD0PSB Richard Jones - KJ5QY wrote: > > I think I found at least one of the problems. > > If you go into the "RX EQ" (by clicking the "MENU" button, then turning > the knob until you see the "RX EQ 1"). Next, turn the lowest base > control (Number 1) up from the "0" EQ position until you here the > distortion on AM. It will not take much. On my rig, just taking it a > few levels (Db) above the "reference" the distortion on AM is there in a > vengeance. > > The following is the most important as I have found: If you have/get the > distortion and you raise the "Shift Control" (While in AM or AM Sync) from > "*150" to "155", the distortion completely goes away!!! I am not sure > what is going on here. > > I hope this, and the posts above will give some additional information on > what I am experiencing, and hopefully an answer. > > Thanks, > > Rick > > > > Richard Jones - KJ5QY wrote: >> >> Hello, >> >> I am having a problem when I go into AM, or AM sync. Example: I go to >> an AM Shortwave station. If I turn the AF gain past approximately 3/4 or >> farther the radio starts to "Stutter, Distort, and finally the audio >> disappears. I cannot make out what is coming out from my speaker. The >> audio is completely distorted or gone. I noticed I could rotate the Af >> gain (Counter Clockwise) and it would go back to less distortion. I did >> check the external speaker jack and also unplugged it only to find the >> same problem. >> >> The AF knob feels like it was one of those "old potentiometers" that we >> are all aware of (Get scratchy after use and loose). From my >> understanding Elecraft used extremely fine pots with a very long life >> (They do have a bad wobble/looseness in them though). >> >> Upon further investigation I found that if I rotated the RF gain control >> from the fully clockwise position (all the way open) to the full counter >> clockwise position (all the way closed) that when you almost get to the >> end of travel the radio audio goes completely dead. I have tried this >> multiples times and it is very repeatable. >> >> After more investigation I found that if I rotated the "shift" (While in >> AM or Sync AM) control from its standard (Normal) value of 1.50 to 1.55 >> this horrible distortion would disappear? I am really confused as to >> what is going on here. >> >> This happens while in the "Normal" AM mode as well as the "Sync" AM mode. >> >> I have tried to explain this in away that I hope most people will >> understand my problem (I am not an EE). >> >> Could others please let me know if it is my unit or a wider problem? >> >> I am using 3.59 and the serial number is 283?. This unit was fully >> loaded and built by Elecraft. >> >> Thanks, >> >> Rick >> > > -- View this message in context: http://n2.nabble.com/K3-Distorted-Sound-while-using-AM-tp4120316p4124780.html Sent from the [K3] mailing list archive at Nabble.com. ______________________________________________________________ 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
