The Tick

 No, not a tiny obnoxious bug that looks like a flat spider - an audio tick.

On my 10 minute timer and Morse Clock kits I included an on the second tick sound.  Since piezo sounders were being used (basically looks like a capacitor to the PIC) I just would change the level of the output from low to high or high to low and let it sit until the next second.  A click sound would result.

But I noticed that WWV and WWVH use a pulse of tone for the on the second tick sound.

https://www.nist.gov/time-distribution/radio-station-wwv/wwv-and-wwvh-digital-time-code-and-broadcast-format

WWV uses 5 cycles of 1000 Hz.  WWVH uses 6 cycles of 1200 Hz.  Both equate to a 5 mS tick.

I tried listening to WWV on 10 MHz and saw this with the scope:

Looks like either the K2 is ringing a bit OR WWV actually uses 7 cycles of 1000 Hz but shapes the tone ?

Anyway, in an upcoming Morse timer kit I changed the tick sound to send 3 cycles of approximately 600 Hz tone.  It is a little louder (obnoxious?) this way and also there's no need to worry if someone hooks a dynamic speaker up (a DC load) in place of the piezo.  A dynamic speaker would increase the power used a lot if the old method of level shift was used.

Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm