Amtor Found 4212 KHZ

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screamin72

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did a bit of searching on Google after I recorded this

http://youtu.be/3vyaSgea7kY

I remember hearing this same type of signal a long time ago when I had a radio that picked up long wave. I read up online it used to be used by amateur operators but now a rarity. I wanted to catch it and find out if anyone has pertinent information on it. I didn't have a proper antenna for 4 mhz. Luck had it that the maximum useable frequency was at 4 mhz for much of the North American continent. surprised the Ham It Up upconverter and RTL-SDR dongle received it with a 18 foot long wire. :)

Error in title 4212khz as you see in the vid.

Edit: daggum it! the title was suppose to be 4212khz USB! Can a mod fix it for me?
 
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ka3jjz

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Moved and re-titled.

We have a number of sites in our wiki that supply not only audio samples, but traces of many digital modes here....(see section 2)

HF Digital Decoding - The RadioReference Wiki

That website mentions PACTOR, not AMTOR (really this would be SITOR-B). Did you decode it? Was it a weather broadcast or ship traffic? There are a few software packages that interface directly with SDRs, and many others you need to use a package known as VAC (virtual audio cable) to pump the audio in

Mike
 
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screamin72

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The time is in UTC in my video in HDSDR and it is really does sound close to AMTOR no i didnt bother decoding it because the signal wasn't stable with it being weak. I don't need to pump audio through any virtual cable when stereo mix input is fine. I only do that for decoding EDACS Provoice. I kinda like those shortwave digital tones.

Pretty close to this AMTOR sample
http://wb8nut.com/resources/amtor.wav

AMTOR is an FSK mode that is hardly used by radio amateurs in the 21st Century. While a robust mode, it only has 5 bits (as did its predecessor RTTY) and can not transfer extended ASCII or any binary data. With a set operating rate of 100 baud, it does not effectively compete with the speed and error correction of more modern ARQ modes like Pactor. The non-ARQ version of this mode is known as FEC, and known as SITOR-B by the Marine Information services.
So you are right about it being SITOR-B FEC. I remember hearing this back in the 1990's. It is AMTOR and confused with PACTOR as PACTOR has shorter bursts.It is beyond the amateur 75 meter band. That frequency is used upon request to Portsmouth/NMN

Look here

http://www.qsl.net/g4hbt/amtor.htm

thanks for fixing my title and moving it. I was guessing where to put it because it was a utility and it can be decoded so I just thought utility was fine because i didnt decode it.
 
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wa8pyr

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So you are right about it being SITOR-B FEC. I remember hearing this back in the 1990's. It is AMTOR and confused with PACTOR as PACTOR has shorter bursts.It is beyond the amateur 75 meter band. That frequency is used upon request to Portsmouth/NMN
AMTOR and SITOR are the same thing, just for some goofy reason using different names.

AMTOR = Amateur Telex (or Teleprinter) Over Radio
SITOR = SImplex Telex (or Teleprinter) Over Radio

I used to run AMTOR/SITOR with a Tono Theta 777 terminal unit; sure was a fun mode and with error correction was great for passing traffic, but has nearly vanished from the ham bands. Still interesting to listen to on the maritime bands when you can find it.

Now I'm kind of motivated to dig the old '777 out of the closet and fire it up....
 

ka3jjz

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There are a number of digital decoding packages that now support SDRs, including the ever popular MultiPSK (strangely that website doesn't list precisely which ones it supports, tho I think one of them is the Funcube). You can find a list of them in section 3.3 of

Software Defined Radios - The RadioReference Wiki

If you have questions about SDRs and interfaces like this, our SDR forum is the place to go...Mike
 
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screamin72

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AMTOR and SITOR are the same thing, just for some goofy reason using different names.

AMTOR = Amateur Telex (or Teleprinter) Over Radio
SITOR = SImplex Telex (or Teleprinter) Over Radio
Thanks for clarifying.
 

prc117f

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did a bit of searching on Google after I recorded this

http://youtu.be/3vyaSgea7kY

I remember hearing this same type of signal a long time ago when I had a radio that picked up long wave. I read up online it used to be used by amateur operators but now a rarity. I wanted to catch it and find out if anyone has pertinent information on it. I didn't have a proper antenna for 4 mhz. Luck had it that the maximum useable frequency was at 4 mhz for much of the North American continent. surprised the Ham It Up upconverter and RTL-SDR dongle received it with a 18 foot long wire. :)

Error in title 4212khz as you see in the vid.

Edit: daggum it! the title was suppose to be 4212khz USB! Can a mod fix it for me?
That link is dead, might as well remove it.
 

ka3jjz

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It's not worth it for a 9 month old thread...

To bring this back a bit - go up 1 khz to 4213 and you may find Shipcom LLC (the outfit that runs stations WLO Alabama and KLB Seattle) with AMTOR mode B - otherwise known as SITOR-B - weather broadcasts...Mike
 
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