K3 CW Reception

[Steve Walter WA3A]

Now that I have my first receiver that actually hears whats on the band (K3 of course) I am in need of some education on cw reception.  I have K3 #3397 with 2.7, 1.8 and 400 hz filters. Latest beta.  
When tuning away from a cw signal and the tone disappears I continue to hear clicking (not quite clicking but more like cw with no tone) for up to another 500 hz. Usually more like 250-300 hz. I normally use the 400 hz filter. Reducing rx bandwidth begins to help around 100 hz but its still noticeable. I believe this is caused by the transmitted cw waveform and the rise and fall times. My understanding is that this is also what causes key clicks but I'm not sure if thats what I'm hearing. To me, key clicks would extend further from the center than what I'm hearing.  Is this what also causes faster cw to use more bandwidth?  It is on all cw signals and not related to strength (although its usually wider with a stronger signal)  or AGC settings (including off).  Of course, on steady carriers I dont hear anything once the tone is gone.  When listening to a TS570 its not nearly as noticeable BUT there are alot of other things going on like AGC pumping and images and just mushy audio in general. Its amazing to me how bad the 570 sounds after using the K3.  
Another part to this question: What does transmitted phase noise sound like on reception? I have read a lot of posts on phase noise but I have no idea what people are hearing.  
And maybe on a related topic I have also noticed SSB splatter much more with the K3.  Is this also related to the K3 just being a cleaner receiver?   None of these issues seem to be rx overload.  I dont use NB, NR and always use the ATT on the lower bands.  As I said before I have tried various AGC settings including agc off and backing off the rf gain with no real difference.  
Maybe I'm just now realizing what alot of you have been talking about... Poorly designed and/or improperly operated transmitters/amplifiers.  If thats the case its an eye(ear)-opener for me!
73, Steve WA3A

[Matt Zilmer]

The on-frequency energy is the transmitter.  Might be key clicks,
waveform shape, etc.  Note that K3's don't cause this type of problem
on TX.

Transmitters that are improperly aligned or operated are much more
noticeable on the K3 than any other rig I've owned.  This is due to
the sensitivity, maybe, but there is always an "expectation factor".
Your use of the ATT is good, but the radio can hear (major deity of
your choice) thinking anyway.  

I recommend frequent experiments with RF GAIN.  This really can get
results.  You need surprisingly little RF gain to copy most anything
on the K3.  A lot of ops run it wide open, but it is the main gain
control at this station on RX.  You may know all this already....

I have a neighbord (1/4 mile away) that has the "clockwise syndrome"
handicap.  Puts out wide band SSB crud.  K3 #24 hears this splatter
better than any receiver I've owned (same neighbor for 20 years, same
problem, but with better ears).  No receiver can make up for crappy TX
output.

If the energy is on frequency, the K3 will probably hear it whether
you want it or not.  Chirps, clicks, splatter, anything.  The positive
side is that this is also true for what you want to hear.

73,
matt W6NIA
K3 #24
K3 #2810

On Sun, 01 Nov 2009 12:58:56 -0800 (PST), you wrote:

>
>Now that I have my first receiver that actually hears whats on the band (K3
>of course) I am in need of some education on cw reception.  I have K3 #3397
>with 2.7, 1.8 and 400 hz filters. Latest beta.  
>When tuning away from a cw signal and the tone disappears I continue to hear
>clicking (not quite clicking but more like cw with no tone) for up to
>another 500 hz. Usually more like 250-300 hz. I normally use the 400 hz
>filter. Reducing rx bandwidth begins to help around 100 hz but its still
>noticeable. I believe this is caused by the transmitted cw waveform and the
>rise and fall times. My understanding is that this is also what causes key
>clicks but I'm not sure if thats what I'm hearing. To me, key clicks would
>extend further from the center than what I'm hearing.  Is this what also
>causes faster cw to use more bandwidth?  It is on all cw signals and not
>related to strength (although its usually wider with a stronger signal)  or
>AGC settings (including off).  Of course, on steady carriers I dont hear
>anything once the tone is gone.  When listening to a TS570 its not nearly as
>noticeable BUT there are alot of other things going on like AGC pumping and
>images and just mushy audio in general. Its amazing to me how bad the 570
>sounds after using the K3.  
>Another part to this question: What does transmitted phase noise sound like
>on reception? I have read a lot of posts on phase noise but I have no idea
>what people are hearing.  
>And maybe on a related topic I have also noticed SSB splatter much more with
>the K3.  Is this also related to the K3 just being a cleaner receiver?  
>None of these issues seem to be rx overload.  I dont use NB, NR and always
>use the ATT on the lower bands.  As I said before I have tried various AGC
>settings including agc off and backing off the rf gain with no real
>difference.  
>Maybe I'm just now realizing what alot of you have been talking about...
>Poorly designed and/or improperly operated transmitters/amplifiers.  If
>thats the case its an eye(ear)-opener for me!
>73, Steve WA3A

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[Joe Malloy]

I've just discovered a 2T-GEN two tone generator kit which I bought not
long before I decided to buy a K3.  As you may know, the K3 has a 2-tone
generator built in, so the one I have is now surplus but would be ideal
for a K2 owner.

So it's for sale.  It's unbuilt, in original packing/pink plastic bag
and it can be yours for $50 including shipping.  Please e-mail me at
w2rba(at)arrl(dot)net.

Thanks and 73,

Joe, W2RBA


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