[Elecraft] K3 And WSJT-X FT8 Timing

[Wes Stewart]

And before that we used CW.  I built a keyer/sequencer (still have it in 
storage) that used an Accu-Memory board with a lot of peripheral CMOS to 
automate the station sequencing.

I counted down the 60 Hz to generate timing, either 15 sec or 2 min depending on 
mode.  This started the changer over sequence and the memory playback.  However, 
the generated CW was run through a shift register (FIFO) with a variable speed 
clock that determined the TX delay, allowing the various stuff to accomplish 
their missions. Some retriggerable one-shots held things in the correct states 
until the message ended and the sequence reversed.

I ran an 8877 and GaAs FET preamp at the antenna and never had a failure except 
when I rushed to get on FM using a multimode (non-sequenced) rig to work W5LFL.  
I blew the antenna preamp and had to climb the tower to bypass it.  I still 
worked him, receiving the signal report, "N7WS 59, the loudest signal we've 
heard in the spacecraft."

Wes  N7WS


On 2/23/2018 1:12 PM, Edward R Cole wrote:
> Guess its time for me to add a couple comments:
>
> Before FT8, before HFers "discovered" JT65,etc., we moonbouncer's had been 
> using JT-65 for nearly 15 years!
>
> Joe Taylor-K1JT invented all these nice new digital modes which originally 
> were designed for ms (meteor scatter) and eme (moonbounce).  Knowing ms and 
> eme stations run QRO on VHF+ with low noise preamps, there was a need to delay 
> the digital transmission so all the various relays and accessories were 
> switched to transmit.  Typically that was 300msec (0.3 seconds). So the sw 
> engages PTT and waits for everything to be ready before sending audio to the 
> transmitter.
>
> Now that "hot shot" HFers are wanting to "Hot switch" their gear a guess FT8 
> and WSJT-X versions have provided for user input on the delay length. <tongue 
> in cheek - don't get upset>
>
> Now you "know the rest of the story".
>
> Note:
> I use a USB/RS232 cable and key with DTR.  I couple audio input and output via 
> two RS audio cables from my external soundcard (emu0202) to my 2010 K3 
> (4340).  I have computer generated audio turned off (no "you have mail" or 
> internet beeps).  Besides, I have a separate computer for normal 
> internet/e-mail, etc.  My dedicated ham radio computer is normally 
> disconnected from internet and I keep computer time by use of a GPS dongle (I 
> can restore internet for K3 fw upgrades).
>
> 73, Ed - KL7UW
>   http://www.kl7uw.com
> Dubus-NA Business mail:
>   dubususa at gmail.com