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Low Line-In level

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Dragan 4O4A

Low Line-In level

I am an occasional user of digital modes.
My K3 is conntected to my PCs via in-line-out cables.

Usually, I used PC speakers gain to about 50-75% of max, and Line level on K3 was about 10 or so. ALC used to be 4 bars, with 5th bar flickering, or lower.

Recently, I cannot setup line-in level as it was before.
Even if I setup both PC audio to 100% and Line to max (60), I can hear very weak sound. VOX (DATA A) works properly, but audio signal is very weak.
If I setup Monitor to max (60), I can hear sound but it is very "dirty".

Where to start? :)

Regards,
Dragan, 4O4A

Don Wilhelm

Re: Low Line-In level

Dragan,

Does the K3 still respond to microphone input as it did before?
If the answer is YES, then I would suspect the soundcard is the source
of your problem.

73,
Don W3FPR

On 11/14/2016 12:48 PM, Dragan 4O4A wrote:

> I am an occasional user of digital modes.
> My K3 is conntected to my PCs via in-line-out cables.
>
> Usually, I used PC speakers gain to about 50-75% of max, and Line level on
> K3 was about 10 or so. ALC used to be 4 bars, with 5th bar flickering, or
> lower.
>
> Recently, I cannot setup line-in level as it was before.
> Even if I setup both PC audio to 100% and Line to max (60), I can hear very
> weak sound. VOX (DATA A) works properly, but audio signal is very weak.
> If I setup Monitor to max (60), I can hear sound but it is very "dirty".
>
> Where to start? :)
>
> Regards,
> Dragan, 4O4A
>
>
>
>
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Dragan 4O4A

Re: Low Line-In level

Hi Don,

When I connect PC line-out to rear MIC, it is a little bit better.
Well, a bit better, I'd say.

However, I'm not sure if it works properly.
Namely, when I give to K3 a steady tone, say 1500 Hz from PC, ALC is "pulsing" and I cannot adjust it properly (3 or 4 bars + 5th flickering).
Tone looks OK on monitor, clean and steady -- no pulses.

I tested two computers (plus one external EMU-0404 sound card) and original problem is always there: low level of signal from PC.

Regards,
Dragan, 4O4A

Don Wilhelm

Re: Low Line-In level

Dragan,

Since you have tested 2 computer soundcards with similar results, I
suggest you contact Elecraft support for further clues to
troubleshooting and resolution.

It still sounds to me that the computer speaker level may be too low for
some reason. If you can get the normal 5 to 7 bars of ALC meter with
the microphone, then you should be able to get 4 bars solid with the 5th
bar flashing in data modes.

Do you have bias set on for the mic connection? - bias should be off.
If it is ON, then the bias voltage may be reducing the output of your
soundcard interface.

73,
Don W3FPR

On 11/17/2016 3:03 PM, Dragan 4O4A wrote:

> Hi Don,
>
> When I connect PC line-out to rear MIC, it is a little bit better.
> Well, a bit better, I'd say.
>
> However, I'm not sure if it works properly.
> Namely, when I give to K3 a steady tone, say 1500 Hz from PC, ALC is
> "pulsing" and I cannot adjust it properly (3 or 4 bars + 5th flickering).
> Tone looks OK on monitor, clean and steady -- no pulses.
>
> I tested two computers (plus one external EMU-0404 sound card) and original
> problem is always there: low level of signal from PC.

Dragan 4O4A

Re: Low Line-In level

I think that PC speakers level is OK. On my headset, on my speakers tone sounds just fine, clean.

I tried to ground PC - no difference.

When connected to MIC input, I tried various BIAS settings. With all three settings (no BIAS, L and H), result is the same except that with High BIAS it needs less sound level to trigger VOX.
Again, with MIC input, sound is OK, but it is pulsing. Sorry for my English, I don't know how to explain "pulsing" :)
I can hear sound well. When K3 meter is showing power, it is stable and no fluctuation. When meter shows ALC, it is "pulsing" slowly from zero to, say, 5 bars and back to zero, with frequency of 1 pulse in second (or so). It looks like ALC is not only limiting sound level, but dropping it back to zero.

I didn't notice any RX problem on other modes, CW or FSK Digi, not even on SSB which I use very rarely (with HM-2 mic).

Don Wilhelm

Re: Low Line-In level

Have you tried replacing the audio cables between the K3 and PC
soundcard? You may have an open shield in the cable.

73,
Don W3FPR

On 11/18/2016 2:14 PM, Dragan 4O4A wrote:

> I think that PC speakers level is OK. On my headset, on my speakers tone
> sounds just fine, clean.
>
> I tried to ground PC - no difference.
>
> When connected to MIC input, I tried various BIAS settings. With all three
> settings (no BIAS, L and H), result is the same except that with High BIAS
> it needs less sound level to trigger VOX.
> Again, with MIC input, sound is OK, but it is pulsing. Sorry for my English,
> I don't know how to explain "pulsing" :)

Dragan 4O4A

Re: Low Line-In level

I have total of three cables (using two at the time, normally). I didn't make them so I'm not sure if it is shielded or not, cables are with ferrite beads next to the jacks, on both sides of cables. I have used those cables for two years, never experienced any problem. Nothing changed in my setup recently, I used this for both WSJT and RTTY ten days ago or so, and it was OK. When I tried WSJT few days ago I found this behavior.

Then I switched my RTTY operations to FSK (to "real" FSK, keying with serial cable).
I liked to use AFSK because of simplicity and I'm aware of importance of ALC settings for clean signal.

I tried to switch cables, but no joy. Still the same.