[Elecraft] [KX3] Re: Why buy a KX2/KX3 compared to a KX1/MTR3B in a QRP portable scenario?

[Phil Wheeler]

Main fun of  the K1 and KX1 is building them :-)

Phil W7OX

On 7/7/16 11:07 AM, Mike Morrow kk5f at arrl.net 
[KX3] wrote:
>
> Barry wrote:
>
> > ...I would have preferred the K1, but I don't 
> believe Elecraft is
> > selling that anymore.
>
> The K1 is still sold...see 
> http://www.elecraft.com/k1_page.htm . The K1 
> remains an excellent small CW-only transceiver. 
> However, the four-band KFL1-4 filter board has 
> been unavailable for a couple of years.
>
> The original posting in this thread contrasted 
> the KX1 vs. KX2 or KX3. If RF performance 
> mattered, where the K1 is clearly superior to 
> the KX1, the 16-year-old K1 deserves honorable 
> mention among small QRP transceivers:
> (1) The K1 uses an LC VFO that is cleaner than 
> the DDS frequency generation scheme of the KX1. 
> This reduces transmitter spurious output, and 
> improves receiver performance because fewer spur 
> frequencies are part of the local oscillator 
> signal fed to the front-end mixer.
> (2) The K1 can be placed on any of the HF bands, 
> although Elecraft sells parts for 80m through 
> 15m only. The KX1 DDS chip is clocked at its 
> maximum rate of 50 MHz, which limits KX1 highest 
> frequency coverage to around those of 20m band.
> (3) The K1 IF uses a four-pole crystal 
> filter...the KX1 IF uses three-pole. This makes 
> a very noticeable difference in selectivity.
> (4) The KAT1 produces a larger number of 
> configurations (1020) of impedance than the 
> KXAT1 (124). (It's of note that the KXAT2 
> produces 32764 different network configurations, 
> 264 *times* the number of the KXAT1. The KXAT3 
> produces 131068 configurations, 1057 times the 
> KXAT1.)
> (5) Many find continuous K1 LC VFO tuning more 
> natural than step-wise KX1 DDS tuning.
> (6) The K1 has a noise blanker option...the KX1 
> does not.
> (7) The K1 transmitter can produce up to seven 
> watts of output power. The KX1 is about half 
> that...at best.
> (8) The K1 case has a speaker...the KX1 does not.
>
> OTOH, the KX1 is clearly superior in terms of 
> VFO stability. It is superior in its span of 
> frequency coverage within the limits of the DDS. 
> It can switch between USB and LSB receive mode 
> due to the frequency agility of the DDS as local 
> oscillator. It has neat features like audio 
> feedback to controls. It is smaller and lighter.
>
> With respect to the KX1 vs. KX2 or KX3, the gulf 
> in capability and performance is so great as to 
> render the question absurd. The only advantage 
> to the KX1 over the KX2 is that Elecraft 
> provides a schematic for the KX1...something 
> that very noticeably withheld for the KX2 and 
> its accessories. That implies the customer is an 
> "appliance operator".
>
> Mike / KK5F
>
> __._,_.___
>