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FW4.51 CWT

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Mike Harris

FW4.51 CWT

I get the impression that the sensitivity of the CWT function has decreased.

Regards,

Mike VP8NO
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Lyle Johnson

Re: FW4.51 CWT

I successfully track a -132 dBm signal using CWT with Thresh of 20 and
PRE OFF. Pretty sensitive :-)

Note that if you have the TEXT DEC Threshold (set by a HOLD of the CWT
button) set to other than Auto, it will blank with weak signals. The
TEXT DEC Threshold is scaled with high AGC Thresholds to allow the CW
Decode Auto mode to work.

73,

Lyle KK7P

> I get the impression that the sensitivity of the CWT function has decreased.

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Scott Manthe-2

Dayton room?

Do any Elecrafters have a Dayton room they won't be using or need a
roomie for Friday night? The Crowne would be great, but that's not the
only place in town.

Contact me via email.

Thanks,
Scott, N9AA

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Mike Harris

Re: FW4.51 CWT

In reply to this post by Lyle Johnson

Hi Lyle,

OK, I wasn't able to put any figure on it. It just didn't seem so
lively. I was listening to some CW on 40m, low output antenna and even
some elements clearly audible above the noise didn't cause the CWT bar
to display. My AGC settings at present are pretty much pre 4.51,
Threshold 8 and slope 6. TEXT DEC is Auto, not that I ever use that
function.

Regards,

Mike VP8NO

On 14/05/2012 19:54, Lyle Johnson wrote:

> I successfully track a -132 dBm signal using CWT with Thresh of 20 and
> PRE OFF. Pretty sensitive :-)
>
> Note that if you have the TEXT DEC Threshold (set by a HOLD of the CWT
> button) set to other than Auto, it will blank with weak signals. The
> TEXT DEC Threshold is scaled with high AGC Thresholds to allow the CW
> Decode Auto mode to work.
>
> 73,
>
> Lyle KK7P
>
>> I get the impression that the sensitivity of the CWT function has decreased.
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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Keith Heimbold

Re: FW4.51 CWT

I have run into the same issue with CWT. I had to turn the noise blanker off for CWT to pick up the signal. I am still playing around with settings and hope to find the proper configuration to get max sensitivity without turning off the NB. I need NB at my QTH. It On SSB, I am enjoying 4.51 though I am still trying to figure out where to put AGC SLP. I like threshold at somewhere between 16-18.

Thanks Elecraft for being so awesome!

Keith
AG6AZ

>>
>>> I get the impression that the sensitivity of the CWT function has decreased.
>>
>> ______________________________________________________________
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>>
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>>
> ______________________________________________________________
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Mike Harris

Re: FW4.51 CWT

G'day,

Further to my first post:

Re installed 4.48. 500Hz filter, XG1 on antenna port 1 (OFF), ATT ON,
THR 8, SLP 6, AGC-F, RF gain Fully CW.

The CWT indicator bar was visible and flickering on noise(?) always to
the right of centre mark by 2 scale marks.

Switched on the XG1 1uV, S-meter to S3, CWT locked and tracks -141Hz to
+133Hz. The CWT bar reaches both ends of the CWT tuning scale and
starts to flicker when the signal as measured by K3 dBV shows a drop of
-2 to -2.6 On tune AFV measures 55. With XG1 OFF AFV measures 7.

Re installed 4.51. No other changes.

The CWT indicator bar not showing.

Switched on XG1 1uV, S-meter to S3, CWT locked and tracks -72Hz to
+100Hz. At the LF end the CWT marker only reaches -3 CWT scale marks
before flickering. At the HF end the CWT marker reaches +5 scale marks
which is end of scale before flickering. Signal level 0.0dBV and
-1.3dBV respectively. On tune AFV measures 55. With XG1 OFF AFV
measures 7. Same as with 4.48.

So without a doubt on my K3 #345 there is a significant change in CWT
behaviour between firmware 4.48 and 4.51. Whilst I don't doubt Lyle's
measurement of CWT tracking at -132dBm it nevertheless failed to solidly
hold a signal I was monitoring on 40m which was 1 S-unit above an S2
noise level.

Is this significant, does it matter if the CWT bar doesn't display until
it has a signal to lock onto? Personally I find it useful that the CWT
bar shows as in 4.48 (as I believe it always has) because it gives an
indication that the CWT function is working.

Oddly the latest CWT mode is pretty much the same as the add on spot
display on my K2 where I adjusted the audio input level to reduce the
amount of flickering on noise. Why do I like one and not the other? No
idea, funny old world.

Don't shoot the messenger.

Regards,

Mike VP8NO

On 15/05/2012 01:37, Keith Heimbold wrote:
> I have run into the same issue with CWT. I had to turn the noise blanker off for CWT to pick up the signal. I am still playing around with settings and hope to find the proper configuration to get max sensitivity without turning off the NB. I need NB at my QTH. It On SSB, I am enjoying 4.51 though I am still trying to figure out where to put AGC SLP. I like threshold at somewhere between 16-18.
>
> Thanks Elecraft for being so awesome!
>
> Keith
> AG6AZ
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wayne burdick

Re: FW4.51 CWT

Administrator

We're looking into this.

tnx
Wayne
N6KR

On May 15, 2012, at 5:07 AM, Mike Harris wrote:

> G'day,
>
> Further to my first post:
>
> Re installed 4.48. 500Hz filter, XG1 on antenna port 1 (OFF), ATT ON,
> THR 8, SLP 6, AGC-F, RF gain Fully CW.
>
> The CWT indicator bar was visible and flickering on noise(?) always to
> the right of centre mark by 2 scale marks.
>
> Switched on the XG1 1uV, S-meter to S3, CWT locked and tracks -141Hz
> to
> +133Hz. The CWT bar reaches both ends of the CWT tuning scale and
> starts to flicker when the signal as measured by K3 dBV shows a drop
> of
> -2 to -2.6 On tune AFV measures 55. With XG1 OFF AFV measures 7.
>
> Re installed 4.51. No other changes.
>
> The CWT indicator bar not showing.
>
> Switched on XG1 1uV, S-meter to S3, CWT locked and tracks -72Hz to
> +100Hz. At the LF end the CWT marker only reaches -3 CWT scale marks
> before flickering. At the HF end the CWT marker reaches +5 scale
> marks
> which is end of scale before flickering. Signal level 0.0dBV and
> -1.3dBV respectively. On tune AFV measures 55. With XG1 OFF AFV
> measures 7. Same as with 4.48.
>
> So without a doubt on my K3 #345 there is a significant change in CWT
> behaviour between firmware 4.48 and 4.51. Whilst I don't doubt Lyle's
> measurement of CWT tracking at -132dBm it nevertheless failed to
> solidly
> hold a signal I was monitoring on 40m which was 1 S-unit above an S2
> noise level.
>
> Is this significant, does it matter if the CWT bar doesn't display
> until
> it has a signal to lock onto? Personally I find it useful that the
> CWT
> bar shows as in 4.48 (as I believe it always has) because it gives an
> indication that the CWT function is working.
>
> Oddly the latest CWT mode is pretty much the same as the add on spot
> display on my K2 where I adjusted the audio input level to reduce the
> amount of flickering on noise. Why do I like one and not the
> other? No
> idea, funny old world.
>
> Don't shoot the messenger.
>
> Regards,
>
> Mike VP8NO
>
>
>
>
>
>
> On 15/05/2012 01:37, Keith Heimbold wrote:
>> I have run into the same issue with CWT. I had to turn the noise
>> blanker off for CWT to pick up the signal. I am still playing
>> around with settings and hope to find the proper configuration to
>> get max sensitivity without turning off the NB. I need NB at my
>> QTH. It On SSB, I am enjoying 4.51 though I am still trying to
>> figure out where to put AGC SLP. I like threshold at somewhere
>> between 16-18.
>>
>> Thanks Elecraft for being so awesome!
>>
>> Keith
>> AG6AZ
> ______________________________________________________________
> 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