[TenTec] On DITS and AMP KEY Switching

[Bob McGraw - K4TAX]

While the QST review does show the timing with respect to key closure and RF 
envelope starting, there's more taking place than is shown in the ARRL 
tests.   There is a third element which seems to be of concern with regard 
to using the Eagle with an external amp.   If the amp has sufficiently fast 
switching, such as found in QSK designed amps, there seems to be no issue. 
These amps will switch in ~5 to ~10 ms typical.  However, with slow 
switching amps, some delay is absolutely necessary as some older amps take 
20ms or more to complete switching.  Discussions continue with regard to the 
fixed timing values offered by the Eagle.

It must be noted that the QSK Delay feature offered by the Eagle is only 
applicable to the receiver recovery between CW elements and does not impact 
any external switching parameters.  It is this point I seem to believe to 
which many are not aware.

I hope I have this correct regarding the timing sequence as measurements 
seem to confirm the following:

(a)  Key closure occurs first.
(b) Amp Key relay then closes some ~7 ms later.  {This is NOT shown in 
QST/ARRL Review}
(c) RF envelope starts ~17 ms after key closure.  The first CW element 
origination is not truncated but only delayed.
(d) Key opens at the end of the CW element.
(e) RF envelope completes.  Thus the CW element is completed some ~17 ms 
after the key opens.
(f) Amp Key relay opens ~20 ms after key opens. {This is not shown in 
QST/ARRL Review}

Hope this helps.

73
Bob, K4TAX

P.S. - Thanks Rick, NJ0IP / DJ0IP for providing the scope pixs.






----- Original Message ----- 
From: "Ken Brown" <ken.d.brown at hawaiiantel.net>
To: <tentec at contesting.com>
Sent: Thursday, September 25, 2014 12:04 AM
Subject: Re: [TenTec] din connector, etc.


> "The dit starts 17mS later and completes 17mS later. The first dit is sent 
> in its full length and the op on the other end never even hears the 
> difference."
>
> That is good to hear. Ten-Tec seems to be the only radio company that 
> understands this. (Correct me if I'm wrong. I hope I'm wrong.)
>
> Almost every radio review I see in QST shows shortened first dits even if 
> they do get the following elements right. Some rigs have a delay on the 
> beginning of the dits and dahs, so amplifiers have time to switch, but 
> fail to add a delay to the end to restore the proper timing of the 
> elements.
>
> DE N6KB
>
>
>
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
>