[Elecraft] ALC for Digi, One Last Check Please

[Bob McGraw K4TAX]

The pulsating is the result of the refresh rate of the display and the 
1500 Hz tone.  Change the TUNE tone to a non- 500 Hz interval such as 
1250 Hz. or 1700 HZ as such.   Yes, in FLDIGI the TUNE tone is a single 
frequency you have selected on the waterfall scale or in the box at the 
bottom of the screen.

When you setup and adjust the audio levels, the radio mode must be DATA 
A for PSK-31.  The audio level for correct ALC indication should show 4 
bars solid with the 5th bar flashing.  The Elecraft radios DO NOT 
operate like other brands in regards to the ALC indications.   The 
actual ALC in the Elecraft starts at and after the 5th bar on the ALC 
scale.   Before that the "audio level" is indicated.    Then set the PWR 
knob on the radio for the power output you desire.   DO NOT adjust the 
audio level to change power.

There are 3 places where audio level is controlled and each one needs to 
be correct.  First is the SPKR level out of the computer.  This should 
be about 30%  {-18 dB} or so.  Then output attenuation on the lower 
right of FLDIGI which should be about -10 dB to -15 dB .  Then the Line 
Gain on the radio {adjusts by the MIC knob} to about 30.   These are 
"ball park" numbers and should get you up and running with a clean 
signal.   If any one or more is near minimum or near maximum, you need 
to investigate further.

If needed I can send screen captures.

73

Bob, K4TAX


On 6/25/2019 2:42 PM, Kevin, N4TT wrote:
> I've made a few PSK-31 contacts on the K3s and I've not gotten any bad
> reports. However, I'm still a little concerned about what I see for ALC.
>
>
> The video below (no audio) shows the ALC meter responding first to a "TUNE"
> command from fldigi. This sounds like a pure tone in the headphones but the
> ALC meter responds oddly, almost like it is pulsating. I expected ALC to
> pretty much be steady.
>
> Next in the video is just clicking T/R in fldigi with no typing. It sounds
> as expected in the headphones (a trilling sound). The ALC response looks
> better but I can still see the pulsations in there. I expected to see 4
> bars solid and the 5th flashing.
>
> https://photos.app.goo.gl/4AaLaVu1r8UDv5LT9
>
> Am I reading too much into this? Is this how your K3s responds?
>
> I'm using the K3s sound card. Level in Windows is -14.7 dB. Level in fldigi
> is -12.7 dB. The level control on the K3s is set for 18.
>
> 73,
> Kev N4TT
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