[Elecraft] K2 audio pops

[Bill Coleman]

On Jul 8, 2008, at 5:41 PM, "" <w4vpi at excite.com> <w4vpi at excite.com>  
wrote:
>
> I have a new k2 that is all but useless as a CW rig because of audio  
> pops when transition from tx to rx.  Pop is also present when power  
> on or pwr off, vol setting no difference in level of pop. Worse with  
> NR off.
>
> There is mention of this problem in years past, but nothing recent,  
> and no good info that I can find. Has anyone seen this in a recent  
> production rig? any ideas?

When I first built my K2/100 #2548, I found that the QSK pops to be  
objectionable. At the time, I was using headphones through a breakout  
box connected to the speaker jack.

When I plugged the headphones into the front panel headphone jack, the  
pops were gone. At least, they were no longer objectionable.

Looking at the schematic, the headphone jack has capacitors across the  
output that aren't present on the speaker. I haven't had a complaint  
since.

You can also reduce the magnitude of the QSK pops by increasing the T- 
R delay time. Elecraft recommends 0.04 to 0.05.

As for the power on / off pops -- I just power up the rig before I  
slip on the headphones.

Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at arrl.net
Quote: "Not within a thousand years will man ever fly!"
             -- Wilbur Wright, 1901