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Custom 700 Hz 8-Pole K3 Roofing” Filter (by INRAD)

700 Hz filter passband roll-off plot .
Passband Roll-Off

12 March 2013 – The next batch of custom 700 Hz 8-pole filters for the Elecraft® K3 is now ship­ping!  For the first time, these fil­ters are avail­a­ble from stock while sup­plies last.  De­pend­ing on de­mand, they’ll prob­a­bly sell out some­time be­tween Day­ton and Field Day.

We can­not yet say wheth­er or not there will be a sub­se­quent batch.  Al­though even if there is, it most like­ly wouldn’t hap­pen un­til 2014.  Use the “Purchase 700 Hz Filters” page to sub­mit your paid or­der.  [purchase now]

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Those of you who are won­der­ing “what’s so special about 700 Hz” may be in­ter­est­ed in what our beta testers have said.  Al­so check out our response to that most fre­quent­ly asked ques­tion.

Due to their lim­it­ed pro­duc­tion vol­ume, these cus­tom fil­ters re­tail for $145 plus our default S&H charge.  The $5 sur­charge – over Ele­craft’s 8-pole fil­ter price – cov­ers the cost of ship­ping the batch from INRAD and the cost to in­sure your in­di­vid­u­al or­der.  [learn more]

Rework Eliminator™ Option Ready K2 Accessory Kits

"Option Ready" Stock K2 .
 
Assembled K2 Internal Mic Adaptor .
Option Bypass Headers
 
Internal Mic Adaptor

Our option bypass headers are ideal for trou­ble­shoot­ing and tin­ker­ing.  These devices sim­pli­fy the task of re­con­fig­ur­ing the Elecraft® K2 to op­er­ate up­on re­mov­al of their as­so­ci­at­ed option Con­verse­ly, they al­so make it pos­si­ble to build a K2 that’s Option Ready from the out­set; when used in con­junc­tion with our re­work-free as­sem­bly method[learn more]  [place an order]

We al­so of­fer “Du­pli­cate K2 PCB Parts” kits for build­ing a stock K2.  These parts en­a­ble you to ful­ly pop­u­late the K2’s three main cir­cuit boards right from the start.  This ap­proach yields a ra­dio that’s much easier to upgrade with op­tions, and potentially more re­li­a­ble.

These kits al­so have the parts you’ll need to add a sec­ond-hand op­tion to a “tra­di­tion­al” K2, (i.e. one that isn’t “Op­tion Ready”).  [learn more]  [place an order]

 

Our K2 internal mic adaptor is an en­gi­neer­ing marvel Check out this PCB scan and this x-ray ren­der­ing to see for your­self.  Once in­stalled, this clever de­vice can be easily ac­cessed by re­mov­ing the K2’s left side pan­el.  And re­wir­ing the mic jack’s pin-out and/or ex­ter­nal bi­as re­sis­tor, is a sim­ple mat­ter of re­arrang­ing jumpers.

A PDF user’s guide shows how to con­fig­ure the adap­tor for 66 pop­u­lar 8-pin Foster mi­cro­phones.  It in­cludes a col­or-cod­ed sche­mat­ic diagram, and a de­tailed de­scrip­tion of the sur­pris­ing­ly flex­i­ble external bias circuit.

The kit in­cludes a self-ad­he­sive decal for handy ref­er­ence.  The 30 mi­cro-inch gold-plat­ed con­tacts are ra­ted for a min­i­mum of 100 jump­er in­ser­tion and re­mov­al cy­cles; suf­fi­cient to en­sure years of re­li­a­ble op­er­a­tion un­der nor­mal use.  [learn more]  [place an order]

Side-by-Side Comparisons
To Add All K2 Options To Change Microphones
Stock K2 Option Ready SSB K2 SSB K2 + IMA
  • Re­move the side pan­els and top cov­er.
  • Re­move the Con­trol board.
  • Re­move and dis­as­sem­ble the Front Pan­el.
  • Re­move the bot­tom cov­er and low­er-rear-pan­el/heat­sink.
  • Re­move the top cov­er.
  • Re­move the top cov­er.
  • Re­move the op­tion­al KAF2 (An­a­log Au­dio Fil­ter) or KDSP2 (Ad­vanced Dig­i­tal Fil­ter) if ei­ther is in­stalled.
  • Re­move the front pan­el sub-as­sem­bly.
  • Re­move the left side pan­el.
  • Un­sol­der/re­move two jump­er wires from the bot­tom of the Con­trol board.
  • Un­sol­der/re­move:  five jump­ers, three re­sis­tors, and two caps from the top of the RF board.
  • Un­sol­der/re­move:  one cap from the bot­tom of the RF board.
  • In­stall:  five caps; one re­sis­tor; one re­sis­tor net­work; and one tran­sis­tor – on the top of the Front Pan­el board.
  • In­stall one DIP con­nect­or on the bot­tom of the Front Pan­el board.
  • In­stall two SIP con­nect­ors on the top of the Con­trol board.
  • In­stall:  sev­en SIP con­nect­ors; four caps; two di­odes; two plugs; and one re­sis­tor – on the top of the RF board.
  • In­stall four stand­offs on the RF board.
  • Un­plug the op­tion by­pass head­ers.
  • If there’s a bi­as re­sis­tor tack sol­dered to the back of the Front Pan­el cir­cuit board, then un­sol­der it.
  • If the new con­fig­u­ra­tion re­quires a bi­as, then tack sol­der the re­quired re­sis­tor on the back of the Front Pan­el cir­cuit board (af­ter de­ter­min­ing which two pins of the mic plug to sol­der it be­tween).
  • Re­move any ex­ist­ing con­fig­u­ra­tion ap­pa­rat­us from P1 (the Mic Con­fig­u­ra­tion Head­er) on the back of the Front pan­el board.
  • Con­fig­ure P1 for the new pin-out.
  • Us­ing small nee­dle-nose pli­ers, re­arrange the jump­ers on the 3×7 jump­er block.
  • In­stall the op­tions.
  • In­stall the op­tions.
  • In­stall the bot­tom cov­er and low­er-rear-pan­el/heat­sink.
  • Re­as­sem­ble and in­stall the Front Pan­el.
  • Re­in­stall the Con­trol board.
  • Re­in­stall the side pan­els and top cov­er.
  • Re­in­stall the top cov­er.
  • Re­at­tach the front pan­el sub-as­sem­bly.
  • Re­in­stall KAF2 (An­a­log Au­dio Fil­ter) or KDSP2 (Ad­vanced Dig­i­tal Fil­ter) if ei­ther had been in­stalled.
  • Re­in­stall the top cov­er.
  • Re­in­stall the left side pan­el.
This is why our customers love our Rework Eliminator™ K2 accessories, and our alternate K2 assembly method.
word cloud of customer comments
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Elecraft is a registered trademark of Elecraft, Inc.
Updated 0227 UTC Wednesday 13 MAR 2013
Rework Eliminator, Rework Eliminators, and unpcbs are trademarks of Ken Kaplan and Gary Hvizdak;
whereas our logo is just an alias for “unpcbs™.com”.  Copyright © 2005 – 2013.  All rights reserved.