[Elecraft] K3 Rear panel audio input problem with - JT65A & 441

[Bill Davis Jr]

   Lance's post was of great interest. I too operate considerable EME (2meters) via WSJT and have just put
my K3 on the air. Yesterday for the first time I attempted to get WSJT running with the K3. The attempt was
not successful.   

  For whatever reason, the K3 rear panel audio input is very insensitive ... to the point of almost being dead. I can barely hear audio through the input, monitoring with a second rig. I have verified the same result with a second audio source, the audio output on my CW keyer. I use a Delta 44 sound card for WSJT and have had no problem with
rear panel audio on my Icom 735, 746Pro or 820H on WSJT or my keyer. The output
level of the Delta 44 was set to +4 and the entire range of the audio
slider was attempted. Again ... all works fine on the Icoms .... The Icoms require the audio gain on the Delta 44 to be up maybe about 1/6th of the way.

 
I have selected MIC+LIN  "ON", LINE IN for gain control and I am using
UpperSideBand as it is standard with all WSJT VHF operations. I know the
rear panel Mic jack works fine, so I am considering using a pad between
the sound card and just using it.

  I found that the rear panel audio output requires gain a setting of around 40 to drive WSJT normally. This is with the Delta 44 audio gain control at maximum. It works, but I was surprised at the required gain settings. When using the headphone output to drive the sound card, the levels were very similar. So maybe all is "ok", it just require considerable more gain than the default. 
 
  I am using no additional interface in my tests since the K3 have transformer isolation. 

  Any insight into what should be a "no brainer"??

Bill  K0AWU  EN37ed  K3 #3460

 






> I have the standard 2.7 kHz filter, and set the audio just like I do for 
> USB voice.  I make sure to have the ALC fill the 5 bars on the meter, and I use 20 dB 
> of compression to make sure that all the tones come up to the proper power levels.  I 
> use the LINE IN on the rear panel for my incoming JT65A tones from the computer.
> 
> I find the K3 a great rig for JT65A because I can make a flat bandwidth 300 Hz to 
> 2200 Hz, and decode callers over that entire frequency range.  I usually run JT65A 
> with the NB on the first setting (IF NAR 1), DSP OFF and the AGC off.  
> 
> GL and VY 73, Lance