[Elecraft] Elecraft technology >> K2+

[N2EY@aol.com]

In a message dated 12/27/03 10:08:42 AM Eastern Standard Time, 
btippett@alum.mit.edu writes:

> N2EY wrote:
> > In one way, the K2 goes back to even earlier, single-band superhet
> > design. That's why its dynamic range figures are so good. Most rig
> > manufacturers aren't likely to move back to this simpler design, largely
> > because they don't want to give up general coverage receive.

Just noticed a typo in that paragraph - should be "single conversion" not 
"single band"


> 
>          I hope your last statement is wrong.  I believe the K2 and Orion's 
> Main RX
> are so superior that they may cause some manufacturers to rethink the need 
> for
> general coverage. 

I hope so too but it's not me you have to convince ;-) Note that the basic 
engineering of the upconversion-to-VHF-first-IF scheme is amortized (by Ikensu) 
over many models - some of them not even ham rigs. 

 Elecraft's K2 design has the basics of an excellent contest
> 
> radio, but it needs attention in two main areas to be truly competitive:
> 
> 1.  Ergonomics...for someone whose hand span exceeds the entire front panel
> width by 1.5" and with finger size to match....for someone who typically 
> spends
> hours in front of the radio in a contest and wants a minimum of menu changes
> (e.g. single-touch access to different filter BW's, etc)...panel readability
> for someone whose eyesight is not what it once was.

Agreed! They don't call me "Big Paws" for nothin'! In fact, I have actually 
thought about putting K2 innards in a bigger box so that much bigger knobs 
could be used on the controls, and they could be spaced farther apart. Such a 
change is not beyond the scope of an experienced homebrewer. All that would be 
needed is a replacement front panel board that would be ribbon-cabled to the 
control board. 

The display is another story, though, because it's a unique part and I doubt 
there is a larger equivalent. So now we're talking major mods to both hardware 
and firmware. 

> 
> 2.  Replacing the programmable crystal filter with fixed BW 8-pole filters
> and <2:1 shape factors (quite achievable at the K2's IF).  The current 
> filter
> has a ~3:1 shape factor which may be one reason the K2's performance 
> degrades
> for IMD and BDR at signal spacings under 5 kHz.  From 5 kHz to 1 kHz signal
> spacings, IMD goes from 88 to 67 dB and BDR goes from 124 dB TO 116 dB.  
> That
> data is from the swept graphs on pages 19 and 20 of ARRL's Expanded Test 
> Report
> done in 2000...pending update of ETR data for the new K2/100 review.
> 
> http://www2.arrl.org/members-only/prodrev/pdf/lab/k2.pdf

Doing that would require major redo of the RF board, plus additional IF gain 
to make up for the additional loss in the filters. I'd suggest relay (not 
diode) switching, too. And perhaps at least a 4 crystal second filter. 

I'd also suggest:

3) Space in the cabinet for all possible options, and a different heatsink 
arrangement for the PA transistors. 

Some folks would like passband tuning, but that's even more of a change to 
the RF board.

Call it "K2BIG"...


The problem with all these changes is that the cost will rise to the point 
where it becomes more of a midline transceiver and less of the lowcost 
highperformance take-anywhere alternative rig that has been the Elecraft paradigm since 
the beginning. Heck, I find it truly amazing that an under-$600-base-price 
kit rig can even be considered in the same discussion with an Orion or FT-1K.

> 
>          With the addition of a K2+ model for performance-oriented 
> contesters
> and DXers in the <$2k range, I believe Elecraft could dramatically expand 
> their
> market while maintaining their original target market for the K2.  Someone 
> is
> going to do this eventually, and it might as well be Elecraft since the K2 
> is
> already very close to what is needed IMHO.
> 

Well, we can ask....

73 de Jim, N2EY



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