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Audio problem in WPX SSB

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Andrew Faber

Audio problem in WPX SSB

Wayne,
A peculiar audio situation arose using my K3 in Aruba in WPX SSB. It
works the same way at home, and isn't a problem I've ever had with any of
many other radios that I've used in the same contest configuration.

Here is what happens: For phone contesting, I my software CQPWIN, which
plays wav files for DVK usage (as do other programs). I run the output in
such a way that when the dvk is playing, the mic is shut off, but the audio
from the computer goes into the mic connector of the radio. As soon as it
stops playing, it disconnects the computer and reconnects the microphone.
I run it from the computer into a W2IHY iBox for isolation, and the output
to the radio. The Mic is a Heil pro-set.

With the K3, the messages play fine, but after one finishes, if I use the
mic, the radio starts out at lower power and takes 2-4 seconds to build back
up to high power. This is the same whether using the front or rear input
and whether using high or low gain. Also, the W2IHY box has to be turned up
to a level that normally would overdrive other radios.

I tried not using the W2IHY box (ie, running the audio straight from
either my laptop or my desktop to the radio) with the same result. It also
doesn't matter if the radio is using PTT or VOX, or whether it just remains
in transmit.

These seems like a some kind of odd impedance issue, but, as I said, it's
one that has never shown up with Icom-Yaesu or Kenwood radios.

Any ideas? I'm using 1.78/1.58 firmware, and the radio was just back to
you for Rene to do hardware mods (serial number 76). In all other respects,
I loved it in the contest.

73, Andy, AE6Y

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Joe Subich, W4TV-3

RE: Audio problem in WPX SSB

> With the K3, the messages play fine, but after one
> finishes, if I use the mic, the radio starts out at lower
> power and takes 2-4 seconds to build back up to high power.
> This is the same whether using the front or rear input
> and whether using high or low gain.

I've noticed the very same thing with the microHAM microKEYER II
and its software DVK. I have not had time to further diagnose
the issue and check it with other interfaces but it is quite
pronounced.

There is no difference if using FP.L or FP.H when the MK II
output is adjusted for four to five bars of ALC. Bias is OFF
and the microphone output of microKEYER II is capacitive
coupled (top and bottom) so there is no "DC effect."

I will not have time to look at this issue further until later
in the week.

73,

... Joe, W4TV

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Andy Faber
> Sent: Monday, April 07, 2008 12:08 AM
> To: [hidden email]; wayne burdick
> Cc: [hidden email]
> Subject: [Elecraft] Audio problem in WPX SSB
>
>
> Wayne,
> A peculiar audio situation arose using my K3 in Aruba in
> WPX SSB. It
> works the same way at home, and isn't a problem I've ever had
> with any of
> many other radios that I've used in the same contest configuration.
>
> Here is what happens: For phone contesting, I my software
> CQPWIN, which
> plays wav files for DVK usage (as do other programs). I run
> the output in
> such a way that when the dvk is playing, the mic is shut off,
> but the audio
> from the computer goes into the mic connector of the radio.
> As soon as it
> stops playing, it disconnects the computer and reconnects the
> microphone.
> I run it from the computer into a W2IHY iBox for isolation,
> and the output
> to the radio. The Mic is a Heil pro-set.
>
> With the K3, the messages play fine, but after one
> finishes, if I use the
> mic, the radio starts out at lower power and takes 2-4
> seconds to build back
> up to high power. This is the same whether using the front
> or rear input
> and whether using high or low gain. Also, the W2IHY box has
> to be turned up
> to a level that normally would overdrive other radios.
>
> I tried not using the W2IHY box (ie, running the audio
> straight from
> either my laptop or my desktop to the radio) with the same
> result. It also
> doesn't matter if the radio is using PTT or VOX, or whether
> it just remains
> in transmit.
>
> These seems like a some kind of odd impedance issue, but,
> as I said, it's
> one that has never shown up with Icom-Yaesu or Kenwood radios.
>
> Any ideas? I'm using 1.78/1.58 firmware, and the radio was
> just back to
> you for Rene to do hardware mods (serial number 76). In all
> other respects,
> I loved it in the contest.
>
> 73, Andy, AE6Y
>
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com

_______________________________________________
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Post to: [hidden email]
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Elecraft web page: http://www.elecraft.com

Don Wilhelm-4

Re: Audio problem in WPX SSB

Joe,

Check Lyle's answer yesterday to similar questions. It is a known
problem and the fix is being field tested right now. You can expect the
firmware release to fix it in about a week according to Lyle.

73,
Don W3FPR

Joe Subich, W4TV wrote:

>> With the K3, the messages play fine, but after one
>> finishes, if I use the mic, the radio starts out at lower
>> power and takes 2-4 seconds to build back up to high power.
>> This is the same whether using the front or rear input
>> and whether using high or low gain.
>>
>
> I've noticed the very same thing with the microHAM microKEYER II
> and its software DVK. I have not had time to further diagnose
> the issue and check it with other interfaces but it is quite
> pronounced.
>
> There is no difference if using FP.L or FP.H when the MK II
> output is adjusted for four to five bars of ALC. Bias is OFF
> and the microphone output of microKEYER II is capacitive
> coupled (top and bottom) so there is no "DC effect."
>
> I will not have time to look at this issue further until later
> in the week.
>
> 73,
>
> ... Joe, W4TV
>
>

Joe Subich, W4TV-3

RE: Audio problem in WPX SSB

Don,

> Check Lyle's answer yesterday to similar questions.

I read Lyle's postings faithfully. I have checked them again
and see no indication that the firmware under test deals with
the "no output after DVK" problem. The discussions center on
certain radios that do not reach PEP even when showing normal
ALC.

> You can expect the firmware release to fix it in about a week
> according to Lyle.

In this case there should be no DC shift (microKEYER II is AC
coupled for both DVK and mic) and no level difference between
DVK (wave file) and mic.

73,

... Joe, W4TV

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Don Wilhelm
> Sent: Monday, April 07, 2008 1:18 PM
> To: [hidden email]
> Cc: [hidden email]
> Subject: Re: [Elecraft] Audio problem in WPX SSB
>
>
> Joe,
>
> Check Lyle's answer yesterday to similar questions. It is a known
> problem and the fix is being field tested right now. You can
> expect the
> firmware release to fix it in about a week according to Lyle.
>
> 73,
> Don W3FPR
>
> Joe Subich, W4TV wrote:
> >> With the K3, the messages play fine, but after one
> >> finishes, if I use the mic, the radio starts out at lower
> >> power and takes 2-4 seconds to build back up to high power.
> >> This is the same whether using the front or rear input
> >> and whether using high or low gain.
> >>
> >
> > I've noticed the very same thing with the microHAM microKEYER II
> > and its software DVK. I have not had time to further diagnose
> > the issue and check it with other interfaces but it is quite
> > pronounced.
> >
> > There is no difference if using FP.L or FP.H when the MK II
> > output is adjusted for four to five bars of ALC. Bias is OFF
> > and the microphone output of microKEYER II is capacitive
> > coupled (top and bottom) so there is no "DC effect."
> >
> > I will not have time to look at this issue further until later
> > in the week.
> >
> > 73,
> >
> > ... Joe, W4TV
> >
> >
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com

Andrew Faber

Re: Audio problem in WPX SSB

Joe,
Yes, I agree. I tried Lyle's suggstion of turning off the ALC in the
config menu, but that didn't help the situation.
73,a ndy, ae6y
----- Original Message -----
From: "Joe Subich, W4TV" <[hidden email]>
To: <[hidden email]>; <[hidden email]>
Cc: <[hidden email]>
Sent: Tuesday, April 08, 2008 7:38 AM
Subject: RE: [Elecraft] Audio problem in WPX SSB

>
> Don,
>
>> Check Lyle's answer yesterday to similar questions.
>
> I read Lyle's postings faithfully. I have checked them again
> and see no indication that the firmware under test deals with
> the "no output after DVK" problem. The discussions center on
> certain radios that do not reach PEP even when showing normal
> ALC.
>
>> You can expect the firmware release to fix it in about a week
>> according to Lyle.
>
> In this case there should be no DC shift (microKEYER II is AC
> coupled for both DVK and mic) and no level difference between
> DVK (wave file) and mic.
>
> 73,
>
> ... Joe, W4TV
>
>
>> -----Original Message-----
>> From: [hidden email]
>> [mailto:[hidden email]] On Behalf Of Don Wilhelm
>> Sent: Monday, April 07, 2008 1:18 PM
>> To: [hidden email]
>> Cc: [hidden email]
>> Subject: Re: [Elecraft] Audio problem in WPX SSB
>>
>>
>> Joe,
>>
>> Check Lyle's answer yesterday to similar questions. It is a known
>> problem and the fix is being field tested right now. You can
>> expect the
>> firmware release to fix it in about a week according to Lyle.
>>
>> 73,
>> Don W3FPR
>>
>> Joe Subich, W4TV wrote:
>> >> With the K3, the messages play fine, but after one
>> >> finishes, if I use the mic, the radio starts out at lower
>> >> power and takes 2-4 seconds to build back up to high power.
>> >> This is the same whether using the front or rear input
>> >> and whether using high or low gain.
>> >>
>> >
>> > I've noticed the very same thing with the microHAM microKEYER II
>> > and its software DVK. I have not had time to further diagnose
>> > the issue and check it with other interfaces but it is quite
>> > pronounced.
>> >
>> > There is no difference if using FP.L or FP.H when the MK II
>> > output is adjusted for four to five bars of ALC. Bias is OFF
>> > and the microphone output of microKEYER II is capacitive
>> > coupled (top and bottom) so there is no "DC effect."
>> >
>> > I will not have time to look at this issue further until later
>> > in the week.
>> >
>> > 73,
>> >
>> > ... Joe, W4TV
>> >
>> >
>> _______________________________________________
>> Elecraft mailing list
>> Post to: [hidden email]
>> You must be a subscriber to post to the list.
>> Subscriber Info (Addr. Change, sub, unsub etc.):
>> http://mailman.qth.net/mailman/listinfo/elecraft
>>
>> Help: http://mailman.qth.net/subscribers.htm
>> Elecraft web page: http://www.elecraft.com
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>

Andrew Faber

Re: Audio problem in WPX SSB

In reply to this post by Don Wilhelm-4

Don,
What answer of Lyle's are you referring to? I think I asked the original
question, but didn't get that answer, as far as I know. Thanks.
73, andy, ae6y
----- Original Message -----
From: "Don Wilhelm" <[hidden email]>
To: <[hidden email]>
Cc: "'Andy Faber'" <[hidden email]>; <[hidden email]>
Sent: Monday, April 07, 2008 10:17 AM
Subject: Re: [Elecraft] Audio problem in WPX SSB

> Joe,
>
> Check Lyle's answer yesterday to similar questions. It is a known problem
> and the fix is being field tested right now. You can expect the firmware
> release to fix it in about a week according to Lyle.
>
> 73,
> Don W3FPR
>
> Joe Subich, W4TV wrote:
>>> With the K3, the messages play fine, but after one finishes, if I use
>>> the mic, the radio starts out at lower power and takes 2-4 seconds to
>>> build back up to high power. This is the same whether using the front or
>>> rear input and whether using high or low gain.
>>
>> I've noticed the very same thing with the microHAM microKEYER II and its
>> software DVK. I have not had time to further diagnose the issue and
>> check it with other interfaces but it is quite pronounced.
>> There is no difference if using FP.L or FP.H when the MK II output is
>> adjusted for four to five bars of ALC. Bias is OFF and the microphone
>> output of microKEYER II is capacitive coupled (top and bottom) so there
>> is no "DC effect."
>> I will not have time to look at this issue further until later in the
>> week.
>> 73,
>> ... Joe, W4TV
>>
>

Joe Subich, W4TV-3

RE: Audio problem in WPX SSB

In reply to this post by Andrew Faber

Andy,

> Here is what happens: For phone contesting, I my software
> CQPWIN, which plays wav files for DVK usage (as do other
> programs). I run the output in such a way that when the dvk
> is playing, the mic is shut off, but the audio from the computer
> goes into the mic connector of the radio. As soon as it stops
> playing, it disconnects the computer and reconnects the
> microphone. I run it from the computer into a W2IHY iBox for
> isolation, and the output to the radio. The Mic is a Heil
> pro-set.

> > With the K3, the messages play fine, but after one finishes,
> if I use the mic, the radio starts out at lower power and takes
> 2-4 seconds to build back up to high power. This is the same
> whether using the front or rear input and whether using high or
> low gain.

After working in this quite a bit over the weekend the problem
is related to the K3 "microphone AGC." It appears that levels
from the microphone and DVK must be extremely well balanced -
much more closely balanced than with any other radio or the
stronger input will cause the microphone AGC to reduce the
mic gain and the weaker input will be much weaker. The 2-4
second delay seems to be related to an extremely long ACG time
constant (probably intended to prevent the ACG from acting like
a clipper).

The problem is made worse - at least in my case - because the
ALC indicator provides only 5 very small, difficult to see,
bars for adjustment and the "steps" are rather course (6 dB
per division). This means that the maximum "spread" between
the two inputs can be almost 12 dB (!) even when the display
only shows a slight flicker between the two adjacent bars
(e.g., the mic is barely triggering the 5th bar and the DVK
is hitting the sixth bar "hard").

After some thought there are several ways (a combination of
all is best) to help the situation:

1) reduce the time constant (AGC "hang") to about .5 second
and "dump" any gain reduction when the PTT is released.

2) Use more of the "ALC" display to get better resolution.
There are 12 "bars" in that part of the display but only
six are used (with the sixth indicating overdrive). At
least expand the "good" range to seven (or eight) bars
to coincide with the right edge of the ALC bracket.

3) Make the ALC display response logarithmic (like a VU
meter). Instead of 5 x 6 dB or 30 dB total ... the same
total range could be displayed with the first bar = -20 dB,
the second = -10 dB, the third = -7 dB, the fourth = -5 dB,
the fifth = -3 dB, the sixth -1 dB, the seventh = "0 dB",
the eighth +1 dB, the ninth +3 dB and the 10th +6 dB.
Setting/matching levels would be MUCH easier. It's no
accident that professional recording and broadcasting have
used similar scales for decades.

4) Give the ALC meter a dual mode display - showing both short
duration "peak" and average (the current ALC) would help.
Alternatively, any "peak hold" dot above the ALC region
could show gain reduction by the mic AGC (and warn about
overdriving the input).

5) Provide a "set-up mode" that disables mic AGC - this
will allow balancing sources (either FP/RP/Line or
multiple inputs on an external mixer) without chasing
the effects of the mic AGC.

I understand there has been some work on the mic AGC in the
firmware currently in test and that may help. However, this
area needs to be more "user friendly." As it is, I can see
significant issues when using the K3 in a multi-operator
setting where the relative levels need to be reset completely
for every operator change!

73,

... Joe, W4TV

Brett Howard

RE: ALC Setting was (Audio problem in WPX SSB)

I agree that corresponding with the end of the ALC bracket makes sense.
I remember looking at the pictures of the radio after it was mentioned
that the 6th bar was overdrive and I was thinking it odd that the
overdrive point didn't correspond to the end of the ALC brackets. My
Kenwood has a line that tells one where the ALC kicks in. It just seems
like that type of operation makes intuitive sense where as the 5 bars
thing is something that one would have to read the manual/reflector to
know.

On Sun, 2008-04-13 at 21:56 -0400, Joe Subich, W4TV wrote:

> Andy,
>
> > Here is what happens: For phone contesting, I my software
> > CQPWIN, which plays wav files for DVK usage (as do other
> > programs). I run the output in such a way that when the dvk
> > is playing, the mic is shut off, but the audio from the computer
> > goes into the mic connector of the radio. As soon as it stops
> > playing, it disconnects the computer and reconnects the
> > microphone. I run it from the computer into a W2IHY iBox for
> > isolation, and the output to the radio. The Mic is a Heil
> > pro-set.
>
> > > With the K3, the messages play fine, but after one finishes,
> > if I use the mic, the radio starts out at lower power and takes
> > 2-4 seconds to build back up to high power. This is the same
> > whether using the front or rear input and whether using high or
> > low gain.
>
> After working in this quite a bit over the weekend the problem
> is related to the K3 "microphone AGC." It appears that levels
> from the microphone and DVK must be extremely well balanced -
> much more closely balanced than with any other radio or the
> stronger input will cause the microphone AGC to reduce the
> mic gain and the weaker input will be much weaker. The 2-4
> second delay seems to be related to an extremely long ACG time
> constant (probably intended to prevent the ACG from acting like
> a clipper).
>
> The problem is made worse - at least in my case - because the
> ALC indicator provides only 5 very small, difficult to see,
> bars for adjustment and the "steps" are rather course (6 dB
> per division). This means that the maximum "spread" between
> the two inputs can be almost 12 dB (!) even when the display
> only shows a slight flicker between the two adjacent bars
> (e.g., the mic is barely triggering the 5th bar and the DVK
> is hitting the sixth bar "hard").
>
> After some thought there are several ways (a combination of
> all is best) to help the situation:
>
> 1) reduce the time constant (AGC "hang") to about .5 second
> and "dump" any gain reduction when the PTT is released.
>
> 2) Use more of the "ALC" display to get better resolution.
> There are 12 "bars" in that part of the display but only
> six are used (with the sixth indicating overdrive). At
> least expand the "good" range to seven (or eight) bars
> to coincide with the right edge of the ALC bracket.
>
> 3) Make the ALC display response logarithmic (like a VU
> meter). Instead of 5 x 6 dB or 30 dB total ... the same
> total range could be displayed with the first bar = -20 dB,
> the second = -10 dB, the third = -7 dB, the fourth = -5 dB,
> the fifth = -3 dB, the sixth -1 dB, the seventh = "0 dB",
> the eighth +1 dB, the ninth +3 dB and the 10th +6 dB.
> Setting/matching levels would be MUCH easier. It's no
> accident that professional recording and broadcasting have
> used similar scales for decades.
>
> 4) Give the ALC meter a dual mode display - showing both short
> duration "peak" and average (the current ALC) would help.
> Alternatively, any "peak hold" dot above the ALC region
> could show gain reduction by the mic AGC (and warn about
> overdriving the input).
>
> 5) Provide a "set-up mode" that disables mic AGC - this
> will allow balancing sources (either FP/RP/Line or
> multiple inputs on an external mixer) without chasing
> the effects of the mic AGC.
>
> I understand there has been some work on the mic AGC in the
> firmware currently in test and that may help. However, this
> area needs to be more "user friendly." As it is, I can see
> significant issues when using the K3 in a multi-operator
> setting where the relative levels need to be reset completely
> for every operator change!
>
> 73,
>
> ... Joe, W4TV
>
>
>
>
> > -----Original Message-----
> > From: [hidden email]
> > [mailto:[hidden email]] On Behalf Of Andy Faber
> > Sent: Monday, April 07, 2008 12:08 AM
> > To: [hidden email]; wayne burdick
> > Cc: [hidden email]
> > Subject: [Elecraft] Audio problem in WPX SSB
> >
> >
> > Wayne,
> > A peculiar audio situation arose using my K3 in Aruba in
> > WPX SSB. It
> > works the same way at home, and isn't a problem I've ever had
> > with any of
> > many other radios that I've used in the same contest configuration.
> >
> > Here is what happens: For phone contesting, I my software
> > CQPWIN, which
> > plays wav files for DVK usage (as do other programs). I run
> > the output in
> > such a way that when the dvk is playing, the mic is shut off,
> > but the audio
> > from the computer goes into the mic connector of the radio.
> > As soon as it
> > stops playing, it disconnects the computer and reconnects the
> > microphone.
> > I run it from the computer into a W2IHY iBox for isolation,
> > and the output
> > to the radio. The Mic is a Heil pro-set.
> >
> > With the K3, the messages play fine, but after one
> > finishes, if I use the
> > mic, the radio starts out at lower power and takes 2-4
> > seconds to build back
> > up to high power. This is the same whether using the front
> > or rear input
> > and whether using high or low gain. Also, the W2IHY box has
> > to be turned up
> > to a level that normally would overdrive other radios.
> >
> > I tried not using the W2IHY box (ie, running the audio
> > straight from
> > either my laptop or my desktop to the radio) with the same
> > result. It also
> > doesn't matter if the radio is using PTT or VOX, or whether
> > it just remains
> > in transmit.
> >
> > These seems like a some kind of odd impedance issue, but,
> > as I said, it's
> > one that has never shown up with Icom-Yaesu or Kenwood radios.
> >
> > Any ideas? I'm using 1.78/1.58 firmware, and the radio was
> > just back to
> > you for Rene to do hardware mods (serial number 76). In all
> > other respects,
> > I loved it in the contest.
> >
> > 73, Andy, AE6Y
> >
> >
> > _______________________________________________
> > Elecraft mailing list
> > Post to: [hidden email]
> > You must be a subscriber to post to the list.
> > Subscriber Info (Addr. Change, sub, unsub etc.):
> > http://mailman.qth.net/mailman/listinfo/elecraft
> >
> > Help: http://mailman.qth.net/subscribers.htm
> > Elecraft web page: http://www.elecraft.com
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com

Andrew Faber

Re: Audio problem in WPX SSB

In reply to this post by Joe Subich, W4TV-3

Joe,
Thanks for the very thoughtful analysis.
I'm very pleased to say that the problem seems to be greatly reduced with
the latest firmware (1.81/1.63). I can't tell if it is completely
eliminated, but it's certainly much reduced. Lyle, Wayne, what did you do?
Whatever it is, it seems to have helped greatly.
73, andy, ae6y
----- Original Message -----
From: "Joe Subich, W4TV" <[hidden email]>
To: "'Andy Faber'" <[hidden email]>; "'wayne burdick'"
<[hidden email]>
Cc: <[hidden email]>
Sent: Sunday, April 13, 2008 6:56 PM
Subject: RE: [Elecraft] Audio problem in WPX SSB

>
> Andy,
>
>> Here is what happens: For phone contesting, I my software
>> CQPWIN, which plays wav files for DVK usage (as do other
>> programs). I run the output in such a way that when the dvk
>> is playing, the mic is shut off, but the audio from the computer
>> goes into the mic connector of the radio. As soon as it stops
>> playing, it disconnects the computer and reconnects the
>> microphone. I run it from the computer into a W2IHY iBox for
>> isolation, and the output to the radio. The Mic is a Heil
>> pro-set.
>
>> > With the K3, the messages play fine, but after one finishes,
>> if I use the mic, the radio starts out at lower power and takes
>> 2-4 seconds to build back up to high power. This is the same
>> whether using the front or rear input and whether using high or
>> low gain.
>
> After working in this quite a bit over the weekend the problem
> is related to the K3 "microphone AGC." It appears that levels
> from the microphone and DVK must be extremely well balanced -
> much more closely balanced than with any other radio or the
> stronger input will cause the microphone AGC to reduce the
> mic gain and the weaker input will be much weaker. The 2-4
> second delay seems to be related to an extremely long ACG time
> constant (probably intended to prevent the ACG from acting like
> a clipper).
>
> The problem is made worse - at least in my case - because the
> ALC indicator provides only 5 very small, difficult to see,
> bars for adjustment and the "steps" are rather course (6 dB
> per division). This means that the maximum "spread" between
> the two inputs can be almost 12 dB (!) even when the display
> only shows a slight flicker between the two adjacent bars
> (e.g., the mic is barely triggering the 5th bar and the DVK
> is hitting the sixth bar "hard").
>
> After some thought there are several ways (a combination of
> all is best) to help the situation:
>
> 1) reduce the time constant (AGC "hang") to about .5 second
> and "dump" any gain reduction when the PTT is released.
>
> 2) Use more of the "ALC" display to get better resolution.
> There are 12 "bars" in that part of the display but only
> six are used (with the sixth indicating overdrive). At
> least expand the "good" range to seven (or eight) bars
> to coincide with the right edge of the ALC bracket.
>
> 3) Make the ALC display response logarithmic (like a VU
> meter). Instead of 5 x 6 dB or 30 dB total ... the same
> total range could be displayed with the first bar = -20 dB,
> the second = -10 dB, the third = -7 dB, the fourth = -5 dB,
> the fifth = -3 dB, the sixth -1 dB, the seventh = "0 dB",
> the eighth +1 dB, the ninth +3 dB and the 10th +6 dB.
> Setting/matching levels would be MUCH easier. It's no
> accident that professional recording and broadcasting have
> used similar scales for decades.
>
> 4) Give the ALC meter a dual mode display - showing both short
> duration "peak" and average (the current ALC) would help.
> Alternatively, any "peak hold" dot above the ALC region
> could show gain reduction by the mic AGC (and warn about
> overdriving the input).
>
> 5) Provide a "set-up mode" that disables mic AGC - this
> will allow balancing sources (either FP/RP/Line or
> multiple inputs on an external mixer) without chasing
> the effects of the mic AGC.
>
> I understand there has been some work on the mic AGC in the
> firmware currently in test and that may help. However, this
> area needs to be more "user friendly." As it is, I can see
> significant issues when using the K3 in a multi-operator
> setting where the relative levels need to be reset completely
> for every operator change!
>
> 73,
>
> ... Joe, W4TV
>
>
>
>
>> -----Original Message-----
>> From: [hidden email]
>> [mailto:[hidden email]] On Behalf Of Andy Faber
>> Sent: Monday, April 07, 2008 12:08 AM
>> To: [hidden email]; wayne burdick
>> Cc: [hidden email]
>> Subject: [Elecraft] Audio problem in WPX SSB
>>
>>
>> Wayne,
>> A peculiar audio situation arose using my K3 in Aruba in
>> WPX SSB. It
>> works the same way at home, and isn't a problem I've ever had
>> with any of
>> many other radios that I've used in the same contest configuration.
>>
>> Here is what happens: For phone contesting, I my software
>> CQPWIN, which
>> plays wav files for DVK usage (as do other programs). I run
>> the output in
>> such a way that when the dvk is playing, the mic is shut off,
>> but the audio
>> from the computer goes into the mic connector of the radio.
>> As soon as it
>> stops playing, it disconnects the computer and reconnects the
>> microphone.
>> I run it from the computer into a W2IHY iBox for isolation,
>> and the output
>> to the radio. The Mic is a Heil pro-set.
>>
>> With the K3, the messages play fine, but after one
>> finishes, if I use the
>> mic, the radio starts out at lower power and takes 2-4
>> seconds to build back
>> up to high power. This is the same whether using the front
>> or rear input
>> and whether using high or low gain. Also, the W2IHY box has
>> to be turned up
>> to a level that normally would overdrive other radios.
>>
>> I tried not using the W2IHY box (ie, running the audio
>> straight from
>> either my laptop or my desktop to the radio) with the same
>> result. It also
>> doesn't matter if the radio is using PTT or VOX, or whether
>> it just remains
>> in transmit.
>>
>> These seems like a some kind of odd impedance issue, but,
>> as I said, it's
>> one that has never shown up with Icom-Yaesu or Kenwood radios.
>>
>> Any ideas? I'm using 1.78/1.58 firmware, and the radio was
>> just back to
>> you for Rene to do hardware mods (serial number 76). In all
>> other respects,
>> I loved it in the contest.
>>
>> 73, Andy, AE6Y
>>
>>
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>
>