by William Eric McFadden

Elecraft K2 -- click to enlarge
(click image to enlarge)

From the manual (rev H, June 23, 2010):

The Elecraft K2 is a high-performance, synthesized, CW/SSB transceiver that covers all HF bands. It is a true dual-purpose transceiver, combining the operating features you’d expect in a home-station rig with the small size and weight of a rugged, go-anywhere portable.

The basic K2 operates on 80-10 meter CW, and provides over 10 watts of RF output. If you prefer a full-power station, you can complete your K2 as a K2/100 at any time by adding the internal 100-watt final stage (KPA100 option). Assembly of the KPA100 is covered in Appendix G, a separate manual supplied with the KPA100 kit.

You can customize your K2 by choosing from a wide range of additional options:

  • SSB adapter with optimized 7-pole crystal filter
  • Automatic antenna tuner (20 W internal or 150 W external)
  • 160-m adapter with receive antenna switch
  • 60-m adapter with low-level transverter interface
  • Computer control interface (RS232)
  • Noise blanker
  • Digital or analog audio filter, each with real-time clock
  • Internal 2.9-Ah rechargeable battery
  • Programmable band decoder
  • High-Performance VHF and UHF transverters

In addition to the options, a companion enclosure the same size and style as the K2 is available for those who wish to build their own matching station accessories (model EC2).

The K2 is an intermediate-level kit, yet you’ll be pleasantly surprised at how uncomplicated it is to build. All of the RF (radio-frequency) circuitry is contained on a single board, while two plug-in modules provide front panel and control functions. Wiring is minimal, unlike traditional kits which depend on complex wiring harnesses.

A unique feature of the K2 is that it provides its own built-in test equipment, including a digital voltmeter, ammeter, wattmeter, complete RF probe, and frequency counter. These circuits are completed early in assembly, so they're ready to be used when you begin construction and alignment of the RF board. We also provide complete troubleshooting and signal-tracing information.

My K2, serial number 1872, is a "rev A" unit with firmware revision 2.04P 1.09 and the single-sideband (KSB2), 160-meters (K160RX), audio filter/clock (KAT2), and noise blanker (KNB2) options.

I bought my transceiver used and can't comment on the building of a K2. I did, however, install the KAT2 and I built and installed the K160RX. (See the links below to find descriptions and photos of K2 builds by Dave Richards, AA7EE, and Alan Wilcox, W3DVX.) This rig has been very reliable; other than realigning the crystal filters, the only repair I've needed to do since my purchase in 2008 has been to replace the AF and RF gain potentiometers in early 2012.

I have a KDSP2 DSP Filter/clock (revision DSP 03.10 CTL 3.10) I purchased used to install my K2; I need to diagnose and repair a high-level audio hiss in the DSP unit before I use it in my rig.

My K2 came to me configured for use with a Kenwood microphone. I have re-configured it to work with an Icom HM-12 microphone I had on hand. I'd like to replace the HM-12 with a Heil Handi Mic HC-5 (link) or the less expensive MFJ-290K; if I do, I'll re-wire the K2 for the simpler Kenwood configuration.

My K2 is the heart of my K2 Travel Kit.

Elecraft K2 advertisement, December 2000 QST -- click to enlarge Manual: Because of changes to the K2 kits over time, several versions of the K2 manual exist. These are available as PDF downloads at Elecraft (link). On the Elecraft site, click "Manuals & Downloads" in the menu, then select "K2". The latest manual will appear in the resulting list. For older versions, click "Manual Archive Page".

Elecraft K2 Advertisements & Brochures:

Elecraft K2 Links:

Elecraft

Attributions: Advertisements scanned from original documents.