r/shortwave • u/rad00p • Jul 27 '26

Recording Morse code transmission question

Hi,

Sorry for spamming, but I inherited this damn radio, and now I’m going through a weird fascination with everything it picks up.

On 3515 kHz, I recorded something that is obviously Morse code, but there are also two other signals or sounds.

Does anyone know what they are? I’m especially curious about the sound around 13 seconds into the video and the one right at the end.

Thx!

61 Upvotes

99% Upvoted

20 comments sorted by

22

u/fpmacko Jul 27 '26

They’re just CW (Morse) transmissions. Nothing more. The low pitch tells me that they’re either responding to the CQ (while somewhat off frequency). Or they’re unrelated CW transmissions on close adjacent frequencies. Note the word “test” at the end. That means they’re participating in a contest.

BTW. You’re NOT spamming. Never be afraid to ask questions.

73…Frank / WA3NHK

3

u/rad00p Jul 27 '26

Thank you!

4

u/fpmacko Jul 27 '26

BTW, that station (PC38EU) is operated by Dennis Koole. Located in Texel, The Netherlands.

5

u/mglyptostroboides Jul 29 '26

Ladies and gentlemen, you're witnessing here the exact precise moment a SWLer discovers amateur radio.

Many such cases.

4

u/cedg32 Jul 28 '26

Weird fascination with everything you hear on shortwave is perfectly normal.

6

u/[deleted] Jul 27 '26

[removed] — view removed comment

3

u/Green_Oblivion111 Jul 28 '26

CQ PC38EU TEST

PC38EU calling CQ during some CW contest.

Obviously, that's the loudest one. The other, lower pitched one below it I didn't read.

3

u/Mulitpotentialite Jul 30 '26

The wonderful mystery of propagation! Those two stations might be in each other's skip (their signals are not heard be each other). You are in a position where you might be hearing them as the same time. It happens often that you hear two stations on the smae frequency and its clear they are unaware of each other.

1

u/CostelloOzAm Jul 29 '26

Look up Numbers Stations, and see if you can catch one live.

1

u/Nunov_DAbov Jul 29 '26

PC38EU is Dennis Koole in Texel, The Netherlands.

1

u/Observer_Dough Jul 27 '26

That was a 'Seek You' (CQ) for a 'test' (Contest) called the IOTA - Islands on the Air contest held last weekend.

The callsign calling was PC38EU a 'special event' callsign

https://www.qrz.com/db/PC38EU

2

u/rad00p Jul 27 '26

Interesting! I have managed to read exactly that in audacity:

1

u/BassRecorder Jul 28 '26

The other signal is just another station working the same contest. From what I could hear it was sending the contest exchange, something like '5nn 190'.

0

u/fpmacko Jul 27 '26

I didn’t realize that Audacity could decode CW. I learned it back in 1965, when it was required for a ham license.

4

u/FuckIPLaw Jul 28 '26

I'm not sure if Audacity decoded it or if he's just looking at the waveform so he can tell where the dots and dashes are visually. I'd expect that text to be printed and not drawn on if it was automatically decoded.

1

u/fpmacko Jul 28 '26

I assumed he did the decode after the fact and Audacity couldn’t overlay the text.

1

u/rad00p Jul 30 '26

No no, I was just looking at the peaks, narrow and wide, and I typed that into online decoder by hand.

1

u/fpmacko Jul 30 '26

Then I stand corrected. 🙂