[TenTec] ORION headphone clicks - the fix!

[Bob Henderson]

I have been experimenting a little further concerning the clicks I 
noticed in my phones.  As I mentioned in a previous post, the clicks I 
hear are always present on the leading edge transition of the first 
character element sent.  Also, at speeds below about 25 wpm I hear a 
click on the leading edge transition of all character elements.  That 
is, except for yesterday, when regardless of the speed at which I was 
sending I heard absolutely no clicks and the sidetone was sweet and 
clear.  Now today, I am experiencing clicks again at speeds below about 
25 wpm.

What is going on here?  Well what is going on is that the band noise 
level is changing.  When the band noise is very low, I hear no clicks 
but as the band noise increases the clicks become evident.  This appears 
consistent with K4IA findings.  The click appears to be produced as a 
result of the presence of band noise during T/R switching.  If I connect 
the Orion to a dummy load there are  no clicks evident at any sending 
speed and regardless how long I send.

So why is the problem accentuated at speeds below 25 wpm?  Well, I'm not 
quite sure but it seems to me there has to be something different in T/R 
sequencing above 25 wpm to that below that speed.  I'm guessing, maybe 
above 25 wpm the receiver doesn't become fully unmuted between character 
elements.  As I say, I'm guessing!

On a noisy band with the clicks in evidence I've had a lot of success in 
reducing the clicks and sometimes removing them completely by increasing 
AGC threshold, which I guess prevents the AGC system from trying to ramp 
the noise up to full output between character elements

All very interesting to me.  Hence I offer my observations for whatever 
you consider they're worth.  In the light of some recent postings, I 
have visions of hundreds  of you rushing to cancel your reflector 
subscription! :-D

73

Bob, 5B4AGN, P3F

K4IA at aol.com wrote:

>I have been doing some more experimenting based on Bob's suggestion to 
>increase the speed.  The clicks went away at about 40 wpm.  A little speedy for me.  
>I usually send around 25 wpm and increase the spacing to make it comfortable 
>for the other guy.
>
>Then I realized what I was hearing was not a click but the background 
>receiver audio coming up when the QSK shifted over to receive.  Yes, it happens that 
>quickly.
>
>I increased the QSK hang time to 20% so the rig doesn't switch over between 
>dits and it sounded better.  I only got the click between letters.  Switching 
>to 40% I only get the noise between words and it sounds less like clicks and 
>more like it really is.
>
>I believe this is "the fix for clix."
>
>Radio k4ia
>Craig "Buck"
>Fredericksburg, Virginia USA
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