[Elecraft] FW4.51 CWT

[Mike Harris]

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