[Elecraft] K3 "No ATU" and 12w max

[David Y.]

Tom and All,

Sounds familiar!  Your K3 serial number is low enough to be one that may be 
affected (mine is #96) by a problem that is fairly easily corrected. 
There's a cap that needs to be removed (if it hasn't been already, and 
another small cap that needs to be added.  I see you have copied Gary 
Surrency, and he will undoubtedly supply you with the complete details (if I 
am right about the issue).

If this happens again in the meantime, try this--disconnect the K3 from all 
power, and let it sit for a while.  It may have to remain disconnected for a 
while.  Chances are that this will temporarily restore your ATU.  Sometimes 
I had to wait 30 minutes to an hour before this worked.  After I made the 
mod, the problem has not returned, so I think it is solved.

Since it is the weekend, you might not hear from Gary until Monday.  I can 
send you the info he sent me, but I'm assuming it's the same problem.  The 
cap that needs to be removed is C19, and the cap that needs to be added is 
an SMT cap (300 pf I think).  You just tack it across two pins on an IC.

Let me know if you need the info.

Dave W7AQK


----- Original Message ----- 
From: <cx7tt at 4email.net>
To: <elecraft at mailman.qth.net>; "Gary Surrency" <support at elecraft.com>
Sent: Saturday, February 06, 2010 3:17 AM
Subject: [Elecraft] K3 "No ATU" and 12w max


> This morning I turned on K3 #250 and got a ERR AT3 msg which was strange
> as when I shut down the radio yesterday, everything was fine. I rarely
> use the ATU as I have a Steppir beam and inverted L which I run thru an
> external tuner.
> I started troubleshooting and went thru the following sequences:
> After seeing the ERR AT3, I check the config, it was in BYP.
> ATU Tune- No ATU
> Config-ATU to auto
> ATU Tune-No ATU
> Power-OFF/ON
> No msg this time
> ATU tune- ERR LPF
> ATU tune-ERR IO3
> ATU tune-ERR IF1
> ATU tune-ERR xv3
> ATU tune-AT3
> ATU tune-ERR PA1
> ATU tine- ERR BP3
>
> Xmit/Tune- 12 w max (KPA100 installed)
> SWR shows 1.8 on K3 display, LP Pan shows 10.6w and SWR of 1.15 (on
> exact Steppir freq of 14.050)
> Same with ATU in BYP or Auto
> KPA3 in nor
>
> Any ideas/suggestions
> 73
> Tom
> CX7TT
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