[Elecraft] [K3] ALC and JTDX

[Don Wilhelm]

Sam,

I don't know what is going on for certain, but are you using DATA A 
mode?  If not, you should be.  It turns off compression and sets the 
equalization flat.  What you are seeing could be the result of using SSB 
with compression turned on.

Secondly, use the LINE IN - there is likely too much gain if you are 
using the microphone input.

Then set the LINE (MIC knob) gain on the K3 to about mid-range (which 
gives more resolution than with the gain at either end of the scale) and 
then use the soundcard slider and possibly the application "power" 
control to obtain the right number of bars on the ALC meter.

It is strange that the JTDX application needs different settings than 
other soundcard data applications.  That certainly points to some 
peculiarity (or error) in the software.

73,
Don W3FPR


On 4/13/2017 3:13 PM, Samuel Cartinhour wrote:
> I recently decided to try JTDX (v 1.7.0), a derivative of the popular WSJT-X software by Joe Taylor. I am using a K3 and an Asus u7 sound card (Windows 7). However, I have run into a snag with respect to ALC.
> 
> When I run WSJT-X, everything works exactly as expected. During transmission I easily obtain four solid ALC bars (with the fifth flickering).
> 
> The same settings do not work for JTDX. In fact, I am not able to find any settings (using the sound card control panel, K3 mic gain, or JTDX pwr slider) that provide four stable ALC bars. At many settings the ALC indicator pulses rapidly from 0 to a level that depends on the settings I choose. The ALC indicator stabilizes only if I push input levels so  that the indicator reads 6 or 7 bars.
> 
> I have done all of the WSJT trials in test mode — I’m reluctant to send anything to the antenna until I figure out what I’m doing wrong.
> 
> Questions:
> 
> Has anyone on the list run JTDX on their K3 and seen this problem? If so, were you able to overcome it?
> 
> What is happening to make the ALC indicator pulse?
> 
> Depending on feedback here, I’ll post to the JTDX list next.
> 
> Thank you,
> 
> Sam W2SNX