I was on 40m when OH8STN sent Heartbeat message from few kilometers away. It was overwhelming my RX and I managed to catch a screenshot.

His message was sent on frequency 889Hz, but we can also see signal harmonic on 1778Hz (2 * 889Hz) and 2667Hz (3 * 889Hz).

Also notice how the width doubles on 2nd harmonic (1778Hz) and triples on 3rd harmonic (2667Hz).

Maybe this doesn't have any other point, but to show how harmonics look like on waterfall.

Sorry, there's error between screenshot and numbers!

I have wrong base frequency here. Screenshot doesn't match the numbers. Clearly in screenshot it's not 889Hz, but something between 900-1000Hz.

My numbers are wrong due to earlier screenshot I took where the base frequency was 889Hz. Sorry about this!

However, the math should still work (just change numbers) and waterfall screenshot shows how it looks.


This is the original screenshot, but since it doesn't fully show the 3rd harmonic I waited for new message. But this one matches the numbers in the first message.

· · Web · 0 · 0 · 1
Sign in to participate in the conversation

Mastodon.Radio is a community space for the Amateur (Ham) Radio community. Come join us and talk radio, technology, and more!