[Elecraft] K3: Line-In dead (or heavily attenuated)

[Joe Subich, W4TV]

> Chokes look fine but L4 and L5 aren't directly connected to 
> line-in; they seem to be connected to the microphone in 
> though. 

According to the schematic, L4 and L5 are line in ... L6 and L7 
are rear panel mic in (L7 is removed in the RFI fix). 

73, 

   ... Joe, W4TV 
 




> -----Original Message-----
> From: James Sarte [mailto:k2qi.nyc at gmail.com] 
> Sent: Wednesday, August 05, 2009 9:40 PM
> To: lists at subich.com
> Cc: Elecraft Reflector
> Subject: Re: [Elecraft] K3: Line-In dead (or heavily attenuated)
> 
> 
> Chokes look fine but L4 and L5 aren't directly connected to 
> line-in; they seem to be connected to the microphone in 
> though. I took the KIO3 apart and traced the line-input 
> circuit for continuity.  The whole board looks good with no 
> cold solder joints.  
> 
> Anyway, I put everything back and voila... works like new.  
> In fact, even better than before.  I only need to set the 
> input gain to about 10 to get a nice signal in from DM780 and 
> registering about 5.5 to 6 bars ALC.  
> 
> This leads me to think two things;
> 
> 1.  Something was loose and my refitting the boards took care 
> of it 2.  There's still a cold solder somewhere that gets 
> affected by heat
> 
> I'll leave the rig on for a while and keep testing.  I'm 
> keeping my fingers crossed.
> 
> 73 de James K2QI
> 
> 
> On Wed, Aug 5, 2009 at 9:10 PM, Joe Subich, W4TV 
> <lists at subich.com> wrote:
> 
> 
> Check the RF chokes L4 and L5 on the KIO3 Audio IO board.
> 
> 73,
> 
>   ... Joe, W4TV
> 
> 
> 
> 
> 
> > -----Original Message-----
> > From: elecraft-bounces at mailman.qth.net 
> > [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of James Sarte
> > Sent: Wednesday, August 05, 2009 7:06 PM
> > To: Elecraft
> > Subject: [Elecraft] K3: Line-In dead (or heavily attenuated)
> >
> >
> > I've sent an email over to Aptos hoping that they may know what's 
> > going on with my K3.  A few days ago, I noticed that sometimes the 
> > amount of line-in gain required for a digital signal from 
> DM780 varied 
> > quite a bit.  Some days, all it took was a level of 14 and I'd have 
> > about 6 bars of ALC.  On others, gain had to be set to nearly 25.  
> > Well, today it seems that my line-in died all together or 
> at the very 
> > least has become heavily attenuated.  I now have to crank the line
> > gain all the way up to 60 to get about 3 bars ALC!!
> >
> > I have checked, and no audio settings have been changed on 
> my PC.  I 
> > even plugged in a set of speakers to the line out jack on 
> the PC and 
> > everything is fine.  What is weird is that sometimes, 
> fiddling around 
> > with the mic/line input settings in the Main menu fixes 
> things for a 
> > while, but then it's back to almost zero input after a while.
> >
> > Any suggestions?  Lyle seems to think it could be a bad 
> solder.  I'm 
> > going to let the rig cool off and see if the problem occurs while 
> > cold.  I've also reloaded the current firmware twice, plus 
> went back 
> > to 3.19 just to make sure it wasn't a FW issue.
> >
> > --
> > 73 de James K2QI
>