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[K3} Setting K3 and WSJT-X levels?

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Don Putnick-6

[K3} Setting K3 and WSJT-X levels?

I know about how to use the S-meter to set transmit audio level (4 bars).
What I've yet to find anywhere is a discussion on whether to favor the
sound card output or the mic gain. In other words, is it better to have a
lower sound card output and a higher mic gain, or vice versa, or does it
matter? And why?
73 and Happy Thanksgiving!
Don NA6Z
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Joe Subich, W4TV-4

Re: [K3} Setting K3 and WSJT-X levels?

On 11/24/2016 1:34 AM, Don Putnick wrote:
> What I've yet to find anywhere is a discussion on whether to favor
> the sound card output or the mic gain. In other words, is it better
> to have a lower sound card output and a higher mic gain, or vice
> versa, or does it matter? And why?

In general, one would preset the sound card output to between 50 and
75% of maximum and leave it there while adjusting the modulation level
with the LINE IN (mic gain in DATA modes).

Most sound cards start to show some distortion above 75 - 80% of full
output and have a fixed level of output noise that is more noticeable
as the output level decreases.

Adjusting to 50 - 75% of maximum output also generally puts the sound
card level in the "sweet spot" (where rig's the mic/line gain is
between 9:00 and 3:00 or 25-75%) for the K3 and many other rigs.

Except for rigs like the K2, KX2, KX3 that fail to provide a "Line In"
(Patch in), never connect a sound card output directly to the mic jack.
Use the Line/Patch in and always disable the mic input when operating
any audio based data mode. If you *must* use the mic jack, connect the
sound card to the mic jack through a 20 dB attenuator (for example,
4.7K resistor from the sound card line out to the mic and 470 Ohm
resistor from the transceiver mic input to mic return).

73,

... Joe, W4TV

On 11/24/2016 1:34 AM, Don Putnick wrote:

> I know about how to use the S-meter to set transmit audio level (4 bars).
> What I've yet to find anywhere is a discussion on whether to favor the
> sound card output or the mic gain. In other words, is it better to have a
> lower sound card output and a higher mic gain, or vice versa, or does it
> matter? And why?
> 73 and Happy Thanksgiving!
> Don NA6Z
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>

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Richard Ferch-2

Re: [K3} Setting K3 and WSJT-X levels?

In reply to this post by Don Putnick-6

You don't want either control to be too close to either end of its range.

If the sound card level is so high that the gain control in the rig has to
be set to only 1 or 2, the granularity of the rig's control becomes a
problem (e.g. set it to 1 and get zero or one bar, set it to 2 and get six
bars, with no way to reach a setting in between). Also, some sound cards
might become non-linear at or near the top of their control ranges, and too
high an input level into the rig might also cause non-linearity introduced
at the rig end of the link before the level control.

If the sound card level is too low, the granularity issue might appear at
the sound card end, and the signal to noise ratio at the input to the radio
might become a problem. You want the audio signal at the input to the rig
to be well above the level of any hum or noise picked up anywhere along the
way, but not so high that it drives the audio circuits into non-linearity.

Ideally, then, you want the rig's Line In level control to be in a
comfortable range (say 6-10 or so) with the sound card's control somewhere
in the middle of its range.

73,
Rich VE3KI

NA6Z wrote:

I know about how to use the S-meter to set transmit audio level (4 bars).
What I've yet to find anywhere is a discussion on whether to favor the
sound card output or the mic gain. In other words, is it better to have a
lower sound card output and a higher mic gain, or vice versa, or does it
matter? And why?
73 and Happy Thanksgiving!
Don NA6Z
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bhemmis

Elecraft KAT500 when powered up generates noise in RX

I searched online but couldn’t find an answer to this. Perhaps someone in the group has a suggestion.
When powering up the KAT500 tuner (used with KPA500) the static level on my Icom 7300 raises to as much as 7 S units of a pulsing ignition-like sounding noise. At first I thought it was a noisy wall wart but tried several and no difference. Then wired it directly to my Astron supply with the same noisy results. The problem is worse on 6 meters but still apparent on the lower bands.
Any thoughts on a fix for this ?
73, Brian K3USC

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Nr4c

Re: [K3} Setting K3 and WSJT-X levels?

In reply to this post by Don Putnick-6

I find the following to work for me.

Set computer output level to about 50%. Now check radio ALC with K3(s) in TEST mode. Observe adjustment of rig to 4bars solid and fifth flashing. If computer is too high, you wind up with 7 bars or none. If ALC setting is low like 2-5, you usually can't get it to be right.

Lower computer output and check again. I keep setting computer lower until I can set the ALC easily. May be 20-30%. But this works for me on K3 and K3S, and KX3.

Sent from my iPhone
...nr4c. bill

> On Nov 24, 2016, at 1:34 AM, Don Putnick <[hidden email]> wrote:
>
> I know about how to use the S-meter to set transmit audio level (4 bars).
> What I've yet to find anywhere is a discussion on whether to favor the
> sound card output or the mic gain. In other words, is it better to have a
> lower sound card output and a higher mic gain, or vice versa, or does it
> matter? And why?
> 73 and Happy Thanksgiving!
> Don NA6Z
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]