DIGITAL TRANSMITION FROM SAQ

[ALEX DELIGIANNIS SV8QG]

I’m hearing most of the transition for years with deferent receiving setup, from tube receivers to SDRs, always trying to decode the Morse message fighting with the QRN. I;m wandering if there is any interest for different experimentation with the Old Lady like transmitting a digital message using OPERA so that more stations around the word have the opportunity to receive the message with the help of a computer.

Topic

[Costas SV1XV]

OPERA is a CW signal, so the bandwidth required is the same as for Morse code with the same “dot” duration .

73 Costas SV1XV

[Ola Hernvall]

What bandwidth is required for transmission with A1D modulation? For your information, the bandwidth of SAQ is 100 Hz.

Best regards,

Ola Hernvall
AlexanderSAQ

[Alexander Hahn]

I hope you will stay with CW as the only SAQ transmission mode forever.
SAQ is not an amateur radio station open for experiments, but a World
Heritage Site for all of mankind. It has started with the Morse code, itself
World Heritage, and it should stay with it.

If you can’t decode Morse, because you haven’t learned it, there are a lot
of Morse decoding programs around.

I record each SAQ transmission and then compare the recording with the
text I’ve written down. Often I have to decode by software to get the text right.

Vy 73, Alex – DH2ID

[Luis EA5DOM]

Very good idea ! 🙂

As Costas said, it is just A1D modulation, so perfectly compatible with the existing keying hardware for CW. Opera is used by Amateurs at 475Khz and 136KHz were it outperforms other weak signal modes
and can be mixed with the standar CW transmissions. Opera just transmits a callsign. Depending on symbol period it can take from 32 seconds to 32 minutes. Due to the strong signal of SAQ it would be
possible to use Opera 8 minutes which can be decoded with very low S/N using correlation detections. Probably good enought for trans Atlantic decodes in daylight

Worth a try 🙂

73 de Luis
EA5DOM

[AlexanderSAQ]

Dear Alex,
Thanks for your message.
The air time for the Old Lady is very limited and has, so far, been dedicated to manual morse code transmissions.
It is certainly an interesting idea to combine more modern transmission technology with the over 90 year old transmitter.
We will give this a thought.

Kind regards,
Fredrik / AlexanderSAQ

[SV1XV]

The proposal of SV8QG for an OPERA transmission following the standard Morse code message is a fine idea. Technically it is very easy, as OPERA is a A1D (CW) mode. For more information about OPERA by EA5HVK see:
https://rosmodem.wordpress.com/
Opera en CQ Radio Amateur (PDF)

73 Costas SV1XV

[Author]

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