[Elecraft] K2 No Side Tone After Firmware Upgrade

[cstoverva at aol.com]

 Hi Don,

This is K2 sn972 I'm upgrading, so it's an oldy.  The firmware chip is 2.04P which I somehow came into possession of while building my first K2 sn5939 a few years ago.  I had Elecraft send only the new I/O chip, so the firmware came to me in pieces.  I didn't see any notes about circuit modifications in the firmware documentation that I have.

I do have the mods located on page 10 of the KIO2 manual.  Just to verify, when you say deletion, are you referring to the cut trace between U6-25 and Q5?  

I own a .001uf cap, some hookup wire and an Exacto knife, so I should be able to knock this out in a few minutes.

Thanks for pointing me in the right place.

Chuck K4QS

 


 

 

-----Original Message-----
From: Don Wilhelm <w3fpr at embarqmail.com>
To: cstoverva at aol.com
Cc: elecraft at mailman.qth.net
Sent: Sun, Mar 14, 2010 3:22 pm
Subject: Re: [Elecraft] K2 No Side Tone After Firmware Upgrade


Chuck, 
 
I would wager that your K2 SN is less than 3000 and that your firmware upgrade is 2.04R (the letter is significant) 
If both those conditions are true, you will have to add the wiring to the Control Board to change the sidetone source from U6 pin 25 to U8 pin 4. 
The latest firmware no longer supports sidetone from U6-25. 
The wire (and capacitor) to be added can be seen in the KIO2 manual or the KPA100 manual (download from www.elecraft.com).  There is one delete that must be made as well. 
There should have been a note to that effect packed with your 2.04R firmware upgrade. 
 
If your K2 serial number is above 3000, then the board change should already be present - do not do any deletes on the control board if the K2 SN is above 3000 - unless you are adding the Keying Waveshape change. 
 
73, 
Don W3FPR 
 
cstoverva at aol.com wrote: 
>  I just aquired my second K2.  It's and older one with a 3 digit serial number that I purchased used. 
> 
> Plans are to build and install a KDSP2.  In preparation for that, I upgraded from firmware MCU2.01 / IOC1.02 to MCU2.04 / IOC1.09. 
> Now I've lost the transmit sidetone.  Toggling between sidetone source U8-4 and U6-25 makes no difference.  Replacing the old firmware restores the sidetone. 
> 
> What am I missing?  Is there a mod to the control board I need to make?  I haven't been able to locate any info.  Any ideas? 
> 
> Thanks. 
> 
> Chuck K4QS 
>   >