[Elecraft] DDS K1.

[EricJ]

I completely agree, Mike. A DDS would add nothing to the K1, but would 
destroy one of its better features--smooth continuous tuning. Step 
tuning is annoying and fatiguing. I never got used to it on the KX1.

Eric
KE6US



On 4/25/2014 1:45 PM, Mike Morrow wrote:
>> Ah, if only we could get a K1 with a DDS VFO!
> Absolutely NOT!!!  True, a DDS VFO adds crystal-like frequency
> stability, and frequency-change agility.  But it also adds many
> spurs on its output that increase spurious emissions on transmit
> and spurious output of the receiver local oscillator to degrade
> receiver performance.  (All this assumes that DDS output is being
> used in the signal paths directly, as it is in the KX1, rather than
> to synch a phase-locked loop voltage controlled oscillator.)  If
> good RF performance is an important criteria, one will always be
> forced to choose an LC VFO over a direct use of DDS in the signal
> path.
>
> Traditionally, DDS chips have been power hungry, although the KX1's
> AD 9834 is very good in that area.  Its maximum clock frequency
> of 75 MHz (earlier, 50 MHz) limits it to frequencies below 25 MHz
> (earlier, 16.7 MHz), which is a big reason why few DDS QRP rigs were
> designed for 15m coverage.
>
> The LC VFO makes a much better performing and cleaner K1, as long as it
> has good stability.  The K1's LC VFO is amazingly stable.  Its continuous
> tuning is far more natural and less fatiguing than the step incremental
> tuning of a DDS rig like the KX1, IMHO.
>
> I would NOT purchase a K1 that had been modified to use the output
> of a DDS directly.
>
>> Everything else remaining the same, because it is the perfect radio!
> Well...let's just say it's the best QRP radio of its size and power
> consumption.  Mine is almost 14 years old and I will never get rid of
> it, unless someone sneaks in and changes it to DDS! :-)
>
>> I have a KX3, but I miss my K1, should have kept it.
> Exactly so.  I'll be ordering a KX3 soon...but my K1 stays forever!
>
> 73,
> Mike / KK5F
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