[Elecraft] Default K3 transmit delay may be too short for slow QRO amplifiers

[Igor Sokolov]

Dear Bob,

My setup is optimized for traveling/field operation. I do not need  
additional boxes in the form of Winkey or external QSK. I use external 
keying from computer through USB-COM adapter. The logger that does CW 
keying is TR4W. No keying compensation helps to achieve correct CW 
weight if TX Delay in K3 is set to say 20ms and CW speed used is above 
30WPM. Dependency of CW weight from TX Delay is only inherent in K3. All 
other rigs do not have this dependency.


73, Igor UA9CDC


08.06.2018 23:12, Bob Wilson, N6TV пишет:
> On Fri, Jun 8, 2018 at 3:22 AM, Igor Sokolov <ua9cdc at gmail.com 
> <mailto:ua9cdc at gmail.com>> 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.
>
>
> Instead of weighting, as Wayne suggested, set "Keying Compensation" or 
> "1st dit extension" to match the actual TX DLY.  This will restore 
> proper CW timing ratios in the transmitted RF, as you increase TX DLY, 
> since every dot or dash (or the first one in a message) will be 
> lengthened by a fixed number of ms.
>
> No footswitch is required, since external keying methods can generate 
> a leading PTT delay.
>
> If you are using the internal keyer of the K3 for hand sending, 
> compensation is automatic.  No need for any adjustment; use any TX DLY 
> value you need, and the transmitted dot/dash ratios will still be 
> perfect (I've measured it on a scope).
>
> If using external keying with a WinKey, use the menu setting for 
> "Keying Compensation" (QSK), or "1st dit extension" (Semi-Breakin).  
> to apply matching keying compensation.  Example:
>
>     CONFIG: TX DLY 010
>     Actual measured TX Delay  7-8 ms (with jitter)
>     Set External Keying Compensation (for QSK) to:  7 ms
>     Set 1st Dit Extension (semi-breakin) to:  7 ms
>
>
> If using a microHAM Device with a built-in WinKey, the menu settings 
> for these values were (unfortunately) moved from the WinKey tab of the 
> Router software.  Instead, they are now a single setting under the PTT 
> tab, called "R/T Delay" (improperly documented).  So, in the microHAM 
> Router, PTT tab:
>
>     Set R/T Delay to 7 ms
>
>
> If using a LogiKey K1 or similar:
>
>     Set the "K Factor" (keying compensatin) to 7
>
>
> If using Win-Test with CONFIG:PTT-KEY OFF-DTR for QSK keying over the 
> serial port DTR pin, or an external keying circuit, set the Keying 
> Compensation in the Interface Configuration menu to 7 ms (this a new 
> feature in Win-Test 4.28.0-dev).  If using semi-breakin, set 
> CONFIG:PTT-KEY to RTS-DTR and tell Win-Test to use a PTT Lead time of 
> 10-20 ms, 0 ms keying compensation.
>
> Most WinKey/N1MM users can simply rely on setting the WinKey PTT Lead 
> time to a sufficient value. Unfortunately, the WinKey PTT lead times 
> are set in increments of 10 ms (0, 10, 20, 30 ms), despite the menu 
> settings.  If you ask for 11 ms of PTT delay in a WinKey, you actually 
> get 20 ms of PTT delay.
>
> Note that the K3 will safely ignore any PTT lead time less than TX 
> DLY, so if you set PTT LEAD to 3 ms you will actually get 7 ms and all 
> elements (QSK) or the first element (semi break-in) will be shortened 
> by 7 ms.
>
> FYI, the OM Power OM2000A+ non-QSK amplifier manual recommends a TX 
> DLY of 20 ms (!).
>
> Final note:  if using CW QRQ mode, the K3 ignores TX DLY completely, 
> and you get 4-5 ms of TX DELAY (fixed, with jitter).  Set keying 
> compensation to 4 ms.
>
> 73,
> Bob, N6TV