K3 S-meter Mode

[Paul Kirley]

When I tried setting K3 CONFIG:SMTR MD to ABS, I found that the S-meter reading then stayed constant regardless of the setting of the preamp/attenuator, in agreement with the Owner's Manual addendum.

However, the reading for a 50-microvolt input signal (with the preamp on and attenuator off) falls from S-9 to S-6 as CONFIG:SMTR MD is changed from NOR to ABS.

Shouldn't a 50-microvolt input signal produce an S-9 reading regardless of the setting of CONFIG:SMTR MD?  

Alternatively, the Owner's Manual S-Meter calibration procedure would need to mention the setting of CONFIG:SMTR MD.

73, Paul W8TM

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[KK7P]

Paul Kirley wrote:
> When I tried setting K3 CONFIG:SMTR MD to ABS, I found that the S-meter reading then stayed constant regardless of the setting of the preamp/attenuator, in agreement with the Owner's Manual addendum.
>
> However, the reading for a 50-microvolt input signal (with the preamp on and attenuator off) falls from S-9 to S-6 as CONFIG:SMTR MD is changed from NOR to ABS.
>
> Shouldn't a 50-microvolt input signal produce an S-9 reading regardless of the setting of CONFIG:SMTR MD?  

No, that is what the ABS mode is available.  You are seeing the correct
response.

In NOR the S Meter is affected by PRE and ATTN.

The default calibration assumes: NOR, PRE ON and ATTN OFF.  The drop you
are seeing when you go to ABS is because the PRE gain is no longer
allowed to affect the S Meter reading.

73,

Lyle KK7P


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[Bill VanAlstyne W5WVO]

Lyle,

I can see the logic in what you say. But if you are using a
particular receiver configuration as your baseline of 50 uv = S9,
I would think that baseline should be the same in ABS mode -- IOW,
50 uv = S9 with preamp on or off, atten on or off. Now, if you
wanted to set the baseline in NOR mode with preamp OFF (which I
really think makes more sense, certainly at the suggested 7 MHz),
then having the S-meter read S9 in ABS mode regardless of
pre/atten settings makes maybe even more sense.

But should that all change at, say, 50 MHz?? You can't hear a
thing on 50 MHz with the preamp off. What about 28 MHz?

The truth is, all this stuff is so very relative to so many
different variables, it's kinda like arguing about how many angels
can dance on the head of a pin. So I'm not really expressing a
strong feeling about a preference here, because at the end of the
day, it doesn't matter much. :-)  And the user can set this stuff
up in the Config menu the way he or she wants to, in any case.

Bill W5WVO


----- Original Message -----
From: "Lyle Johnson" <[hidden email]>
To: "Paul Kirley" <[hidden email]>
Cc: <[hidden email]>
Sent: Sunday, August 31, 2008 7:31 PM
Subject: Re: [Elecraft] K3 S-meter Mode


> Paul Kirley wrote:
> > When I tried setting K3 CONFIG:SMTR MD to ABS, I found that
the S-meter reading then stayed constant regardless of the setting
of the preamp/attenuator, in agreement with the Owner's Manual
addendum.
> >
> > However, the reading for a 50-microvolt input signal (with the
preamp on and attenuator off) falls from S-9 to S-6 as CONFIG:SMTR
MD is changed from NOR to ABS.
> >
> > Shouldn't a 50-microvolt input signal produce an S-9 reading
regardless of the setting of CONFIG:SMTR MD?
>
> No, that is what the ABS mode is available.  You are seeing the
correct
> response.
>
> In NOR the S Meter is affected by PRE and ATTN.
>
> The default calibration assumes: NOR, PRE ON and ATTN OFF.  The
drop you
> are seeing when you go to ABS is because the PRE gain is no
longer

> allowed to affect the S Meter reading.
>
> 73,
>
> Lyle KK7P
>
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
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>
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> Elecraft web page: http://www.elecraft.com

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