The K3 rise time isn't 2.5msec. Here's what N6KR said on the subject to
the Field tester group in May 2010. This comment was partly in response to
whether rise time would be shortened for the new K3 QRQ mode.
"Rise and fall times are fixed at about 4-5 ms. There is widespread general
agreement that this is optimum, and at present I have no plans to allow
changing it. Some ops want faster rise time to *cause* clicks (so they can
hold a frequency), but I won't be doing that. We're taking the high road on
this, just like we do on not applying fast ALC post-crystal filter."
73, Barry N1EU
On Thu, Feb 25, 2016 at 2:22 AM, David Gilbert <xdavid@cis-broadband.com>
wrote:
>
> Jukka has based all his comments on something he recently read on Nabble
> ... apparently without noticing that the reference was originally posted
> way back in 2009 (seven years ago). In addition, it appears that he didn't
> even understand the post, which states that the K3 originally had a pretty
> soft rise/fall time of
> 8 msec which was SHORTENED to about 2.5 msec after Elecraft implemented
> the special shaped waveform that is still in use today.
>
> In other words, the K3 never had harsh keying ... even before the firmware
> change. Jukka has got it all backwards.
>
> Dave AB7E
>
>
> Dave AB7E
>
>
>
> On 2/24/2016 4:35 PM, Jim Brown wrote:
>
>> On Wed,2/24/2016 6:27 AM, Jukka Klemola wrote:
>>
>>> I am going to think a little and make a write up somewhere on the subject
>>>
>>
>> Rather than "think," it would probably be far better if you were to STUDY
>> the documentation for modern radios and the impartial testing done by ARRL
>> Labs, and published on their website. I have done that quite extensively,
>> and have written it up in k9yc.com/TXNoise.pdf These are FACTS that I
>> have taken the time to learn, not opinions.
>>
>> Again, you speak of firmware upgrades for the K3 "solving" a problem with
>> clicks. I've been using K3s with legal limit amps since 2008. I do not
>> recall ever having an issue with clicks -- if I did, K6XX, who lives five
>> miles from me, would have told me! Again, you have bad information.
>>
>> Beginning with the K3 and all of its accessories, firmware upgrades are
>> nearly automatic. The firmware update utility (one for Windoze and one for
>> Mac) queries the radio via a serial or USB port, queries the website and
>> downloads the latest firmware, asks if you want to update, and if you say
>> yes, it does that.
>>
>> I first published TXNoise about 18 months ago. It clearly showed that
>> Yaesu radios were by far the dirtiest on CW, with very excessive clicks and
>> phase noise. A few months later, they issued a firmware update that
>> significantly improved the keying performance of the FTDX5000 and others in
>> that family. Likewise, ARRL's review of the Flex 6500 and 6700 SDRs showed
>> really awful CW bandwidth. A few months later, Flex issued a firmware
>> update that significantly improved the keying performance.
>>
>> In TXNoise, I noted the connection between rise/fall time and keying
>> bandwidth, and stated the simple rule that if it is adjustable, slower
>> produces the cleanest result.
>>
>> I would like to update TXNoise with results for the 6500/6700 radios
>> after their firmware upgrade, but have so far been unsuccessful in having
>> an owner loan his rig for measurement. N6TA loaned his FTDX5000 for before
>> and after measurements, and they are on my website.
>>
>> http://k9yc.com/P3_Spectrum_Measurements.pdf
>>
>> 73, Jim K9YC
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>>
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