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DDS K1.

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Gil G.

DDS K1.

Ah, if only we could get a K1 with a DDS VFO!
Everything else remaining the same, because
it is the perfect radio!
I have a KX3, but I miss my K1, should have
kept it..

Gil.
--
PGP Key: http://keskydee.com/gil.asc

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Phil Wheeler-2

Re: DDS K1.

Yes, that's a plus of the KX1, with the 3080
option it has RX from 1.0 to 16.5 or so MHz. Handy
at times.

73, Phil w7ox

On 4/25/14, 9:22 AM, Gil G. wrote:
> Ah, if only we could get a K1 with a DDS VFO!
> Everything else remaining the same, because
> it is the perfect radio!
> I have a KX3, but I miss my K1, should have
> kept it..
>
> Gil.

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Mike Morrow-3

Re: DDS K1.

In reply to this post by Gil G.

> 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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EricJ-2

Re: DDS K1.

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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>

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k1-4 user

Re: DDS K1.

In reply to this post by Gil G.

I enjoy my K1 and its LC VFO, but always liked the idea of a 15 or 20 turn
LC to allow a slower tuning rate with the wider band coverage.

Robin
KA5QQA
On Apr 25, 2014 11:23 AM, "Gil G." <[hidden email]> wrote:

> Ah, if only we could get a K1 with a DDS VFO!
> Everything else remaining the same, because
> it is the perfect radio!
> I have a KX3, but I miss my K1, should have
> kept it..
>
> Gil.
> --
> PGP Key: http://keskydee.com/gil.asc
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>