[Elecraft] K3 QSK Timing

[K9ZTV]

For any practical purpose needed by amateur radio operators that I can think of, the ability to hear between elements is not a life-and-death virtue.  The ability to hear between characters is by far magical enough.  

I speak as one who has been doing 30 wpm full-QSK traffic work for 60 years, beginning with Johnson and B&W vacuum tube electronic T/R switches common in the late fifties and early sixties.

Back then the trick was to prevent RF from the transmitter being pumped directly into the receiver when both were connected “live” to the same antenna.  

The other issue was how to monitor one’s sending.  Some operators preferred muting their receivers and listening on an external monitor.  While some electronic T/R switches did have provisions for receiver muting, if unmuting was not fast enough, QSK itself was compromised.  Personally, I preferred copying on the unmuted RF-protected but RF Gain-reduced receiver itself.

Using separate transmitters and receivers with no internal switching mechanism, the main worry in those days was protecting the receiver from RF.  Today, using nothing but transceivers, the main worry is protecting relays from hot-switching (especially in linear amplifiers).

I was reading the mail recently on a couple of high-speed ops enjoying a lengthy QSO together, punctuated by frequent break-ins from the listening side.  By the time the sender had heard and reacted to the break-in, at least one and sometimes two (depending on length) complete words (not elements or characters) had already been transmitted.

In short, hearing between elements gave us bragging fodder but served no real practical purpose.  Hearing between characters was (and remains) way good enough for CW traffic work, and, in my opinion, Elecraft pin-diode switching is the best of the best.

73,

Kent  K9ZTV


> On Jun 2, 2020, someone wrote:
> 
> The practical QSK limit for the TS-590S was about 26 wpm. Any faster than that and the receiver did not "open" between elements.
>