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Loggings => HF Mystery Signals => Topic started by: shortwavedrama on October 02, 2024, 1901 UTC

Title: Monster on 13.500 MHz
Post by: shortwavedrama on October 02, 2024, 1901 UTC

There is a 120 kHz wide signal centered on 13.500 MHz.  There is an occasional CW signal in there beast heard using NFM.
CW appears to be "NIEEA TENT AAIA".
Signal has been strong all day, currently S9 in the western US at 19:00z on Oct 2.
Just heard another CW? transmission.  Text changes.

Audio of CW: https://drive.proton.me/urls/MJ5Z35Z3SR#B3KjRGjq86OZ
Short IQ recording: https://drive.proton.me/urls/FYDG724FMR#ePWhbb9HKv9e
Screenshot of signal: https://drive.proton.me/urls/R2H2WHVQ5M#yxZ8XXanWJfn

Edit: Appears similar to CODAR but I notices a total of six carriers moving back and forth at the same rate.

Title: Re: Monster on 13.500 MHz
Post by: shortwavedrama on October 02, 2024, 1925 UTC

I tried the W3HFU 900' skywave loop; the signal was mainly a high frequency to low frequency sweep, the low to high sweeps would be heard lighter occasionally.

Title: Re: Monster on 13.500 MHz
Post by: northern_dxer on October 03, 2024, 0826 UTC

Looks like two CODARs (a type of marine research radar) to me. Or similar radars used for similar purpose. One is sweeping upwards, the other is sweeping downwards. 13.5 MHz lies on a frequency band which is reserved for marine research radars. The CW message may be one of the radars identifying itself, or it may come form another source.

Title: Re: Monster on 13.500 MHz
Post by: wilddog on January 12, 2025, 1315 UTC

There is another signal on 13561 KHz. Right?