Login  Register

Re: Default K3 transmit delay may be too short for slow QRO amplifiers

Posted by Joe Subich, W4TV-4 on Jun 08, 2018; 6:04pm
URL: http://elecraft.85.s1.nabble.com/Default-K3-transmit-delay-may-be-too-short-for-slow-QRO-amplifiers-tp7641790p7641805.html



On 2018-06-08 10:53 AM, [hidden email] wrote:
 > Does computer keying with Winkey still perform properly with
 > longer TX delays?

If you use the PTT output of WinKey with computer keying, the
delay is a non factor.  Set TX Lead in WinKey as needed for
your amplifier and the WinKey keyer will assert PTT *before*
the CW output (key closure) by the desired value.  Allowing
PTT to "lead" the output will not result in any character
clipping.

73,

    ... Joe, W4TV


On 2018-06-08 10:53 AM, [hidden email] wrote:

> I am sure that just adding a few ms will work with most amplifiers but my
> question was what exactly happens to CW. Is it just the first dit that gets
> clipped.  Does computer keying with Winkey still perform properly with
> longer TX delays?
>
> John KK9A
>
> Sent via the Samsung Galaxy 7 edge, an AT&T 4G LTE smartphone.
>
> On Fri, Jun 8, 2018 at 10:48 AM, Wayne Burdick <[hidden email]> wrote:
>
>> Also, a reminder: this is nothing new. We’re just clarifying a delay
>> offset that has existed for a long time. There have been no recent firmware
>> changes.
>>
>> It would be possible to modify the K3’s keying algorithm to allow for much
>> longer delays (say, 0 to 200 ms). Of course this would significantly shift
>> CW RF output in time relative to keying input.
>>
>> Fortunately, very few amplifiers require more that a few ms of extra
>> delay.
>>
>> 73,
>> Wayne
>> N6KR
>>
>>
>> ----
>> http://www.elecraft.com
>>
>>> On Jun 8, 2018, at 7:33 AM, Wayne Burdick <[hidden email]> wrote:
>>>
>>> The delay can be set from 8-20 ms at present. Given the small time
>> offset, this is actually 5-17 ms (approx). Use small values if possible.
>>>
>>> With external keying, you can generally compensate by reducing the
>> device’s weighting.
>>>
>>> Wayne
>>>
>>> ----
>>> http://www.elecraft.com
>>>
>>>> On Jun 8, 2018, at 5:02 AM, "[hidden email]" <[hidden email]> wrote:
>>>>
>>>> I agree that 5ms is too fast for many amplifiers. Is computer sent CW
>> also
>>>> spoiled when increasing the delay?  Does it only effect QSK or all
>>>> transmissions?
>>>>
>>>> John KK9A
>>>>
>>>> Igor Sokolov ua9cdc wrote:
>>>>
>>>> Wayne it is a pity that TX delay setting affects CW timing. Changing TX
>>>> delay from default even one or two steps makes CW much worth. Can you
>>>> figure out a way to make CW timing independent from TX delay? With 5 ms
>>>> TX delay working in many contests I already had to change a pair of
>>>> relays in the amplifier. 10-12 ms would be fine for me. 20 ms will
>>>> probably suit the majority of users. But 5 ms is way too fast and
>>>> unfortunately cannot be altered without spoiling CW sending. I know that
>>>> I could build external sequencer but this does not look neat enough
>>>> especially for portable field operation. Every other radio I had allowed
>>>> TX delay adjustment to at least 20 ms.
>>>>
>>>> 73, Igor UA9CDC
>>>>
>>>> ______________________________________________________________
>>>> 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]
>>
> ______________________________________________________________
> 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]
>
______________________________________________________________
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]