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MCU 4.51

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Tobyp

MCU 4.51

Mike, you could be correct. This morning I seem to have a little distortion in the NB which I did not notice before. It's not bad, but a little is there.

I may go back to 4.50 just to check it out.

Toby W4CAk

I just got it tonight. I have not had much chance to compare but the NB
in 4.50 is much better! A curious unexpected side effect!

Mike W0MU
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w0mu

Re: MCU 4.51 NB

I did not mean to imply that the NB had changed from 4.50 to 4.51. My
comment was from 4.48 to 4.5X.

I can see how you read it differently though.

I have not noticed a change in the NB from .50 to .51

Mike W0MU

W0MU-1 CC Cluster w0mu.net

On 5/12/2012 6:30 AM, Toby Pennington wrote:

> Mike, you could be correct. This morning I seem to have a little distortion in the NB which I did not notice before. It's not bad, but a little is there.
>
> I may go back to 4.50 just to check it out.
>
> Toby W4CAk
>
>
>
> I just got it tonight. I have not had much chance to compare but the NB
> in 4.50 is much better! A curious unexpected side effect!
>
> Mike W0MU
> ______________________________________________________________
> 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

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Ted Bryant

Re: MCU 4.51 NB

Was v4.51 sent to the 4.50 testers? If so, I missed it.

The major difference I've noticed with 4.50 is that cw signals, especially
the low level ones, now seem much "cleaner".

73, Ted W4NZ

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]]On Behalf Of W0MU Mike Fatchett
Sent: Saturday, May 12, 2012 11:22 AM
To: [hidden email]
Subject: Re: [Elecraft] MCU 4.51 NB

I did not mean to imply that the NB had changed from 4.50 to 4.51. My
comment was from 4.48 to 4.5X.

I can see how you read it differently though.

I have not noticed a change in the NB from .50 to .51

Mike W0MU

W0MU-1 CC Cluster w0mu.net

On 5/12/2012 6:30 AM, Toby Pennington wrote:
> Mike, you could be correct. This morning I seem to have a little
distortion in the NB which I did not notice before. It's not bad, but a
little is there.

>
> I may go back to 4.50 just to check it out.
>
> Toby W4CAk
>
>
>
> I just got it tonight. I have not had much chance to compare but the NB
> in 4.50 is much better! A curious unexpected side effect!
>
> Mike W0MU

Dave wo2x

Re: MCU 4.51 NB

I too received 4.50 but not 4.51

73
Dave
wo2x

Sent from my iPhone

On May 12, 2012, at 12:17 PM, "Ted Bryant" <[hidden email]> wrote:

> Was v4.51 sent to the 4.50 testers? If so, I missed it.
>
> The major difference I've noticed with 4.50 is that cw signals, especially
> the low level ones, now seem much "cleaner".
>
> 73, Ted W4NZ
>
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]]On Behalf Of W0MU Mike Fatchett
> Sent: Saturday, May 12, 2012 11:22 AM
> To: [hidden email]
> Subject: Re: [Elecraft] MCU 4.51 NB
>
>
> I did not mean to imply that the NB had changed from 4.50 to 4.51. My
> comment was from 4.48 to 4.5X.
>
> I can see how you read it differently though.
>
> I have not noticed a change in the NB from .50 to .51
>
> Mike W0MU
>
> W0MU-1 CC Cluster w0mu.net
>
>
> On 5/12/2012 6:30 AM, Toby Pennington wrote:
>> Mike, you could be correct. This morning I seem to have a little
> distortion in the NB which I did not notice before. It's not bad, but a
> little is there.
>>
>> I may go back to 4.50 just to check it out.
>>
>> Toby W4CAk
>>
>>
>>
>> I just got it tonight. I have not had much chance to compare but the NB
>> in 4.50 is much better! A curious unexpected side effect!
>>
>> Mike W0MU
>
> ______________________________________________________________
> 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

Joe Subich, W4TV-4

Re: MCU 4.51 NB

In reply to this post by Ted Bryant

On 5/12/2012 12:17 PM, Ted Bryant wrote:
> Was v4.51 sent to the 4.50 testers?

Apparently not all (I had to request it).

I've been doing some crude testing ... with 4.51 AGC THR = 15 is
approximately -73 dBm/S9 (to the best of my ability to measure with
the XG3 and step attenuator).

With high values for AGC THR it is important to use higher values of
AGC SLP otherwise a sudden very strong signal will drive the audio
amp and/or headphone amp into severe distortion - particularly if the
AF Gain is high.

I'm finding AGC THR in the 12/13 range and SLP in the 8/10 range is
very comfortable and seems to "open up" the K3 receiver. The only
problem is that my poor antennas don't given me enough strong signals
to really evaluate strong signal pile-up with off air signals at the
higher thresholds.

73,

... Joe, W4TV

On 5/12/2012 12:17 PM, Ted Bryant wrote:

Charles Johnson

Re: MCU 4.51 NB

In reply to this post by Ted Bryant

Same here. Lower level CW signals are much clearer and not nearly so mushy in crowded conditions.

I received 4.50 but haven't received 4.51. Would like to try it out as well.

73, Charles, K4ZRJ

On May 12, 2012, at 12:17 PM, Ted Bryant wrote:

Sebastian, W4AS

Re: MCU 4.51 NB

In reply to this post by Joe Subich, W4TV-4

I'm not a fan of NR, however since it's back in 4.51, I decided to try it again.

I thought some of the NR settings appeared to be excessive, to the point of eliminating the signal I'm trying to listen to. But then I remembered that finding the best NR setting takes time (it's not instant).

Setting NR F4-4 on CW with a relatively strong signal is amazing. At first it seems as if the audio has been turned down completely as the background noise disappears; but when the CW signal comes back, it's nice and crisp and at a good audio level. This is with AGC THR at 16 and SLP at 9.

The not so good news: there is a 'thud' heard on CW mode when the AGC THR is increased starting at 15 up to 20, and then from 20 down to 15; regardless of the SLP setting. On SSB it's more of a 'swoosh' sound.

This could have something to do with the receive equalizer as it doesn't occur in TX DATA mode where it is bypassed. Was it there before?

73 de Sebastian, W4AS

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wayne burdick

Re: MCU 4.51 NB

Administrator

Sebastian,

The AGC threshold is something the typical operator will rarely
change. We didn't make any effort to eliminate switching artifacts as
you change the menu parameter, though we could if it turns out to be
an issue.

73,
Wayne
N6KR

On May 12, 2012, at 11:30 AM, Sebastian, W4AS wrote:

> I'm not a fan of NR, however since it's back in 4.51, I decided to
> try it again.
>
> I thought some of the NR settings appeared to be excessive, to the
> point of eliminating the signal I'm trying to listen to. But then I
> remembered that finding the best NR setting takes time (it's not
> instant).
>
> Setting NR F4-4 on CW with a relatively strong signal is amazing.
> At first it seems as if the audio has been turned down completely as
> the background noise disappears; but when the CW signal comes back,
> it's nice and crisp and at a good audio level. This is with AGC THR
> at 16 and SLP at 9.
>
> The not so good news: there is a 'thud' heard on CW mode when the
> AGC THR is increased starting at 15 up to 20, and then from 20 down
> to 15; regardless of the SLP setting. On SSB it's more of a
> 'swoosh' sound.
>
> This could have something to do with the receive equalizer as it
> doesn't occur in TX DATA mode where it is bypassed. Was it there
> before?
>
> 73 de Sebastian, W4AS

David Cutter

Re: MCU 4.51 NB

In reply to this post by Joe Subich, W4TV-4

Would it help the tests to engage the pre-amp? ie make things more
challenging.

David
G3UNA

On 12/05/2012 17:22, Joe Subich, W4TV wrote:

>
> On 5/12/2012 12:17 PM, Ted Bryant wrote:
> > Was v4.51 sent to the 4.50 testers?
>
> Apparently not all (I had to request it).
>
> I've been doing some crude testing ... with 4.51 AGC THR = 15 is
> approximately -73 dBm/S9 (to the best of my ability to measure with
> the XG3 and step attenuator).
>
> With high values for AGC THR it is important to use higher values of
> AGC SLP otherwise a sudden very strong signal will drive the audio
> amp and/or headphone amp into severe distortion - particularly if the
> AF Gain is high.
>
> I'm finding AGC THR in the 12/13 range and SLP in the 8/10 range is
> very comfortable and seems to "open up" the K3 receiver. The only
> problem is that my poor antennas don't given me enough strong signals
> to really evaluate strong signal pile-up with off air signals at the
> higher thresholds.
>
> 73,
>
> ... Joe, W4TV
>
>
> On 5/12/2012 12:17 PM, Ted Bryant wrote:
>> Was v4.51 sent to the 4.50 testers? If so, I missed it.
>>
>> The major difference I've noticed with 4.50 is that cw signals, especially
>> the low level ones, now seem much "cleaner".
>>
>> 73, Ted W4NZ
>>
>>
>> -----Original Message-----
>> From: [hidden email]
>> [mailto:[hidden email]]On Behalf Of W0MU Mike Fatchett
>> Sent: Saturday, May 12, 2012 11:22 AM
>> To: [hidden email]
>> Subject: Re: [Elecraft] MCU 4.51 NB
>>
>>
>> I did not mean to imply that the NB had changed from 4.50 to 4.51. My
>> comment was from 4.48 to 4.5X.
>>
>> I can see how you read it differently though.
>>
>> I have not noticed a change in the NB from .50 to .51
>>
>> Mike W0MU
>>
>> W0MU-1 CC Cluster w0mu.net
>>
>>
>> On 5/12/2012 6:30 AM, Toby Pennington wrote:
>>> Mike, you could be correct. This morning I seem to have a little
>> distortion in the NB which I did not notice before. It's not bad, but a
>> little is there.
>>> I may go back to 4.50 just to check it out.
>>>
>>> Toby W4CAk
>>>
>>>
>>>
>>> I just got it tonight. I have not had much chance to compare but the NB
>>> in 4.50 is much better! A curious unexpected side effect!
>>>
>>> Mike W0MU
>> ______________________________________________________________
>> 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
>>
> ______________________________________________________________
> 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
>

Don Wilhelm-4

Re: MCU 4.51 NB

I fail to see any advantage to turning on the preamp when it is not
needed. If you can hear the atmospheric noise without the preamp, leave
it off (if the noise level increases when the antenna is attached, you
have enough gain). By extension, if you can still hear the atmospheric
noise with the attenuator in, leave it in - using more front end gain
than is necessary for the band and antenna conditions will only reduce
the dynamic range of the receiver. If you do not know what that means
in terms of operating, let me put it simply - you may not hear that weak
one that you would have heard if you had set the preamp and attenuator
properly.

Technical discussion - the band noise is S-3 with the preamp off. The
K3 will start to overload on a signal that is S9+70, and will hear
signals that are greater than the S-3 band noise level. Turn the preamp
on, and the band noise raises to about S-5, but the K3 overloads on that
signal that is now S9+70, so you can now only hear between S5 and S9+70
where before you could hear between S3 and S9+70. You have reduced the
dynamic range by turning on the preamp when it was not needed.
BTW - The S9+70 overload point I used was just an example off the top of
my head - I do not have the overload point for the K3 at handy
reference, so use that as a "for instance" rather than as an absolute
data point. (also BTW - my "overload" term is technically referred to
as the "compression" point).

73,
Don W3FPR

On 5/12/2012 6:56 PM, David Cutter wrote:

> Would it help the tests to engage the pre-amp? ie make things more
> challenging.
>
> David
> G3UNA
>
> On 12/05/2012 17:22, Joe Subich, W4TV wrote:
>> On 5/12/2012 12:17 PM, Ted Bryant wrote:
>> > Was v4.51 sent to the 4.50 testers?
>>
>> Apparently not all (I had to request it).
>>
>> I've been doing some crude testing ... with 4.51 AGC THR = 15 is
>> approximately -73 dBm/S9 (to the best of my ability to measure with
>> the XG3 and step attenuator).
>>
>> With high values for AGC THR it is important to use higher values of
>> AGC SLP otherwise a sudden very strong signal will drive the audio
>> amp and/or headphone amp into severe distortion - particularly if the
>> AF Gain is high.
>>
>> I'm finding AGC THR in the 12/13 range and SLP in the 8/10 range is
>> very comfortable and seems to "open up" the K3 receiver. The only
>> problem is that my poor antennas don't given me enough strong signals
>> to really evaluate strong signal pile-up with off air signals at the
>> higher thresholds.
>>
>> 73,
>>
>> ... Joe, W4TV
>>
>>