[Elecraft] K2 Upgrade

[Don Wilhelm]

Mike,

Download the A to B instructions from Elecraft, and look at the first 
page.  It will have a list of other associated upgrade kits.
If you think some of the upgrades have already been installed, download 
the instructions for each and do a physical examination of the K2 to see 
if any of those have been previously installed.
In addition to those upgrades, look at the designations on the IF 
crystals.  If they do not end in "-S", those crystals should be updated 
as well for better filter performance.  If the KSB2 is installed, look 
at those crystals as well.  If you need to update the KSB2 crystals as 
well as the main RF board IF crystals, order the matched set of 14 
crystals - if only the RF board needs updated, order the set of 7 crystals.
If you are replacing the crystals on the KSB2 board, consider widening 
the OP1 filter width to 2.4kHz instead of the original 2.1kHz.
Of course, you should update the firmware.

In addition, the AF Gain control is likely to be scratchy, so order a 
new AF Gain pot and install the Alternate AF Gain Control Wiring mod.

I would advocate doing all the upgrades at once while you have it open.  
The cost of each of the mod kits is quite reasonable ($10 to $20 range), 
but the firmware is priced at $54 and is the most expensive part of the 
upgrade.

If there is no KSB2 board, then the 2nd Xtal Flattening Mod can be 
skipped, but I would install all the others, including the crystal change.

73,
Don W3FPR

On 9/2/2015 5:28 PM, Mike Herr wrote:
> I am looking to upgrade a friend's older K2, sn 280. What mods are
> recommended as necessary and what would be in the nice to have category.
> This is a plain vanilla K2, CW only, QRP, no 160, 60 meters, etc.
>