Topband: Key Clicks

[Paul Christensen]

> ALC is part of the power control loop, and is not adjustable in rigs 
> without a "drive" control.

It's unfortunate that there is not a better way of automatically managing 
ALC in most radios.  Although I like the ability to manually adjust drive 
level on the IC-7800, I think many operators just instinctively want to see 
ALC action on both CW and SSB.  So, it's a double-edged sword: when used 
correctly, its a wonderful tool.  But my measurements show that if ALC is 
not monitored and tempered on the 7800, really bad things happen.  The 
default 4 ms setting is actually quite good if drive is set exactly to the 
ALC threshold point.  Tuning off to the side when listening on my TS-870 in 
a wide 6 kHz Rx BW, things sound pretty much identical when the 7800 is 
selected between 4ms, and 6ms.  But going down to 2 ms creates some 
noticeable clicks.  Increase the drive lever further and things go to Hell 
in a hurry.

My understanding of the new Ten Tec Omni VII is that in addition to 
selectable CW rise/decay time, quite a bit of attention was paid to the ALC 
circuit and I believe Gary Barbour indicated to me at the Ten Tec Hamfest 
that a dual-speed power loop is part of the design.  Anyway, looking forward 
to those results.

> I have a question Paul. What ALC level does ICOM say to run on CW? Do they 
> tell you to barely run the ALC up with the drive control?

I've gone through the manual, and perhaps I'm missing it but I do not see 
any recommendation from Icom.  So, it seems the user is left to figure this 
out for him or herself.

Paul, W9AC