K2 Internal Option Basics

K2 Internal Option Basics

K2 Internal Option Basics

K2 Internal Option Basics

K2 front panel
Image courtesy of Elecraft, Inc.

The Elecraft® K2 is …

  1. A fun-to-build HF trans­ceiv­er kit, with by far the hot­test re­ceiv­er in its price range!
  2. Ide­al­ly suit­ed to por­ta­ble use giv­en its small size and in­cred­i­bly low re­ceive pow­er con­sump­tion.
  3. An ex­cel­lent “first rig”, with a bar­gain $759.95 in­tro­duc­to­ry price tag for the base ra­dio.
  4. High­ly ex­pand­a­ble thanks to ten “op­tion­al mod­ules” (op­tions) which can be in­stalled in any of 431 dif­fer­ent com­bi­na­tions.

The ti­ny K2 is able to sup­port so many op­tions, be­cause six of the ten in­stall in the same phys­i­cal space and use the same elec­tri­cal con­nec­tions as an­oth­er op­tion or group of op­tions.  This is why its ten op­tions can only be in­stalled in 431 (rath­er than 210 – 1 = 1023) com­bi­na­tions.  Bor­row­ing ter­mi­nol­o­gy from prob­a­bil­ity theo­ry, it could be said that the in­stal­la­tion of most op­tions is mu­tu­al­ly ex­clu­sive with the in­stal­la­tion of oth­er op­tions; mean­ing that you can only in­stall one or the oth­er, but not both at the same time.  So even though ten op­tions are avail­a­ble, at most only six (for the QRO con­fig­u­ra­tion) or eight (for the QRP con­fig­u­ra­tion) can be in­stalled in a K2 at the same time.

Fig­ur­ing out which op­tion com­bi­na­tions are val­id can make con­tem­plat­ing your in­itial K2 pur­chase seem a bit over­whelm­ing at first, even be­fore con­sid­er­ing our rework-free “Option Ready” K2 as­sem­bly method and our Re­work Elim­i­na­tor™ af­ter­mar­ket ac­ces­so­ries.  For­tu­nate­ly this sub­ject is easy to un­der­stand with the aid of an il­lus­tra­tion.

Re­fer­ring to the di­a­gram below, six Elecraft® op­tions (the K60XV, K160RX, KNB2, KSB2, KAF2, and KDSP2) plug di­rect­ly on­to the K2’s RF or Con­trol cir­cuit board via one or more Sin­gle In­line Pack­age (SIP) con­nect­ors.  These are the op­tions that can be quickly in­ter­changed with our Re­work Elim­i­na­tor™ op­tion by­pass headers, (A.K.A. un-modules).  The oth­er four Elecraft® op­tions mount in­side the top cov­er and con­nect to the K2’s main cir­cuit boards via ca­bles.  Un-mod­ules are not ap­pli­ca­ble to these op­tions.

As al­ready men­tioned, the in­stal­la­tion of some op­tions or op­tion com­bi­na­tions is mu­tu­al­ly ex­clu­sive with oth­er op­tions.  Spe­cif­i­cal­ly, you can in­stall ei­ther of two aux­il­ia­ry au­dio fil­ters on the Con­trol board – ei­ther the orig­i­nal an­a­log fil­ter (KAF2) or an ad­vanced dig­i­tal sig­nal pro­ces­sor (KDSP2).  You al­so have a choice of ei­ther the QRP top cov­er op­tions (KBT2, KAT2, and/or KIO2 in any com­bi­na­tion) or the QRO top cov­er (KPA100).  The four op­tions (K60XV, K160RX, KNB2, and KSB2) that mount on the RF board, are the only ones whose in­stal­la­tion is not mu­tu­al­ly ex­clu­sive with oth­er op­tions.  They each have their own ded­i­cat­ed mount­ing lo­ca­tion and can be in­stalled in any com­bi­na­tion.

Con­nect­or P4 (Aux I/O) on the Con­trol board is in­clud­ed with the base K2 kit, while eve­ry­thing that’s shown cross-hatched is op­tion­al.  The KIO2 in­cludes a small ‘ Y ’ split­ter board which al­lows both the KIO2 and the KAT2 to con­nect to P4 at the same time.  Plugs RF-P6 (Aux RF) and RF-P3 (Aux 12V) are sup­plied with each of the op­tions that re­quire them.

K2 Internal Options
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Updated 1258 UTC Sunday 11 MAY 2014
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