LA3ZA Unofficial Guide to Elecraft K2 Modifications

I started this table when the number of modifications on the Elecraft email reflector started to overwhelm me, and I could no longer find modifications or determine whether they were important to do or not. After the K2 was revised in October 2002 (serial number 3000), this became much easier. Therefore the list is organized in three different sections:

General modifications applicable to any K2 (last update 6 April 2010)
Elecraft modifications to bring your K2 up to date with serial numbers 3000+ (last update 15 Oct 2006)
Elecraft modifications that took place for various serial numbers prior to 3000 (last update16 May 2005)

The first section consists of modifications that are meant to adapt the K2 to various user needs, or they are simply modifications contributed by K2 owners who found building so fun that they could not stop after the K2 was completed. This section also covers a few performance modifications contributed after the serial number 3000 revision was done, some of which are now standard. Sections 2 and 3 will help you bring an old K2 (serial no <3000) up to date with the latest modifications generated or approved by Elecraft.

In any case, it is highly recommended that you assemble the K2 as is, tune it, and make your first contacts before considering any modifications. After you get some experience, you may go back to the list and consider the modifications.

If you have additional modifications, corrections, comments, or find broken links, please contact me.

I hope you will find the list helpful and will have as much fun as I have had building, upgrading, modifying, breaking and fixing my K2 in addition to operating it!

73, Sverre Holm, LA3ZA

Resources for understanding the K2:

A compilation of K2 schematics
Data sheets for most of the major components of the K2 (WB4VLQ) (scroll about one page down)
Data sheets for most of the semiconductors of the K2 (DF7TV)
Reflections from the Elecraft E-mail reflector (VE3MCF)
Elecraft’s latest Builder Alerts

Resources for aligning and troubleshooting the K2:

Alignment instructions extracted from K2 manual (W3FPR)
K2 Cheap and Dirty Signal Tracing (N0SS)
K2 receiver sensitivity check (K8ZOA)

Resources for building and modifying the K2:

Disclaimer: The modifications presented here have not all been officially endorsed by Elecraft. They should not be implemented before the K2 works and is tuned properly. The authors of these modifications or the author of this web-page will not be liable for any damage that they may cause to the K2. However, these modifications have all been implemented by home-brewers and we have no reason to believe that they will not give the desired effect on other K2s.

First version 22 Nov 2001.