[Elecraft] Older option boards from K3 upgrade

[Guy Olinger K2AV]

The second K3 listing from top on the Sherwood (old syns) vs the first
K3 listing from top (K3 modded with new syns) is as good an A/B RX
test as you will ever get. Note: there is a separate K3S listing.
Print out the first page of the Sherwood listing in landscape mode,
and then fold the paper to put the two listing lines next to one
another.

It is quite true that many typical and ordinary ham situations will
not demonstrate the difference, but weak signal work on any band,
those improvements will make a difference, because phase noise is not
additive, it modulates band noise. This will have more effect on
signals from low signal RX antennas that are not pre-amped.

My K3 with the new syns is better in sound stage diversity, but that
is in the brain and I don't know the mechanism for the improvement,
hence entirely subjective. I suspect something related to allowing
band noise to come through less modulated by phase noise, but
absolutely zero proof.

On a diversity sound stage, noise is scattered around the "horizon"
with some discrete noise taking fixed positions. The noise sounds less
"muddy" with new syns, that's as good as I can describe that.

I'm still trying to find a series of attachments showing a progression
of phase noise on steady TX carrier with one at a time syn changes
between two close K3 owners. I'm now thinking it was on one of those
Tiny URL kinds of things and perhaps not widely distributed. I don't
have email with attachments regarding that synthesizer test.

And I'm one of the worst at figuring out the secret word to pump a
google search.

And yes, the diff in CQ shaping was obvious in seconds after syn replacement.

There is some stuff on Elecraft's Nabble searchable list showing A/B keying.

73, Guy

On Wed, Apr 26, 2017 at 1:20 AM, Vic Rosenthal <k2vco.vic at gmail.com> wrote:
> The improvement in QSK performance and elimination of jitter in CW timing was immediately noticeable even without an a/b test. Night and day.
>
> Vic 4X6GP
>
>> On 26 Apr 2017, at 0:06, Guy Olinger K2AV <k2av.guy at gmail.com> wrote:
>>
>> Many times, with spectrum analyzer screen prints, etc. Some of those
>> in the near-astounding category.
>>
>> At this point can't refer you to them but you can find them with some searching.
>>
>> A 3 dB improvement in TX strength will not be noticed either, until it
>> is used in a situation where you're close to or in the noise.
>>
>> Close neighbor hams with a sequence of installing the syns, and screen
>> prints in the reduction in phase noise sidebands for each step, and
>> noticeable improvement in interfering with one another. For me that
>> was the killer demo.
>>
>> The "news" aspect of the syns is pretty well past, so don't see much
>> about it any more.
>>
>> 73, Guy
>>
>>
>>
>>> On Tue, Apr 25, 2017 at 4:33 PM, Wes Stewart <wes_n7ws at triconet.org> wrote:
>>> I've seen these rave reviews about the new synthesizer many times.  Has
>>> anyone actually done an A/B comparison in real time with two otherwise
>>> identical radios.
>>>
>>> I have a K3 with the original synthesizer (the actual one used to develop
>>> the stiffener plate) and a K3S.  I have not run them side-by-side since I
>>> don't have any test equipment with sufficiently low phase noise to use.
>>> Anecdotally, using them one at a time in day-to-day operation, I haven't
>>> noticed a difference.
>>>
>>> Wes  N7WS
>>>
>>>
>>>> On 4/25/2017 1:14 PM, Guy Olinger K2AV wrote:
>>>>
>>>> I tossed my old synthesizers, in accordance with my dropping my old
>>>> closet hoarder policy of keeping any and all for 40 years to see if it
>>>> might be of any use. I actuarially doubt I will see another 40 years.
>>>>
>>>> The synthesizer mod has met with such documented success, that I
>>>> routinely advise someone looking for a used K3 not to bother unless
>>>> the new synthesizer(s) are in it. Or to work a discount on any K3
>>>> without them to offset the cost of the synthesizer(s) to be done
>>>> immediately.
>>>>
>>>> All this became apparent very early on after the new synthesizers were
>>>> introduced.
>>>
>>>
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