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#1
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![]() From: "Ralph Mowery" Organization: EarthLink Inc. -- http://www.EarthLink.net Newsgroups: rec.radio.shortwave,rec.radio.amateur.digital.misc ,rec.ham-radio Date: Sat, 12 Feb 2005 13:08:16 GMT Subject: Rtty Protocol Most hams are received in the LSB mode. Comercial statisons usually are received in the USB mode or the reversed mark/space relationship. Also the speed (baud rate) and shift are usually differant than the normal ham 45 baud (60 wpm) and 170 Hz shift. "B.R. Smith" wrote in message ... I am using Ham Scope and Mmtty to decode RTTY with my sound card. It works fine for hame radio operators but I have found RTTY on non-ham frquencies and all I get is garbage. For example, there is an RTTY signal at approximately 2.042 MHZ at 1100 UTC on the West Coast and all that displays is random characters. I suspect it has something to do with the protocol or baud rate settings. Anyone know what they might be? Not sure if this is maritime station or not. Thanks. Okay, I have some questions about RTTY: 1. What unencrypted RTTY traffic is out there besides hams? 2. What sort of encoder would I need to read RTTY with my NRD-525 and what do I need to know to get it functioning? 3. My receiver has an RTTY mode. What exactly does that do in my receiver? Couldn't I just use USB or LSB? Thanks, Greg |
#2
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![]() "Greg" wrote in message ... Okay, I have some questions about RTTY: 1. What unencrypted RTTY traffic is out there besides hams? I am not sure about RTTY that is not ham now. I doubt much is in use. There used to be some using other shifts and upside down from the ham standard. You may find a list on rtty.com 2. What sort of encoder would I need to read RTTY with my NRD-525 and what do I need to know to get it functioning? YOu can use your computer with the built in sound card. There are several free programs you can use . MMTTY is a good one to start with. Go here to get the programs. http://www.muenster.de/~welp/sb.htm YOu just hook the sound card input to the speaker or output of the receiver. Even a mic on the computer layed next to the speakers will work in a quiet location. 3. My receiver has an RTTY mode. What exactly does that do in my receiver? Couldn't I just use USB or LSB? The reciever will go to either the LSB or USB mode but the filters will be shifted so they will be centered at higher audio frequencies. The normal ham rtty audio tones are 2125 hz and 2295 hz for the normal 170 hz shift. In real use the receiver could be tuned so that almost any lower frequencies are comming out of the speaker and the demodulator (converter or sound card freqwuencies) set for the lower frequencies. The way it was done in the precomputer days were with fixed filters and it was hard to change the tuning of them. By using lsb and the mark tone of 2125 (think that was a multple of some audio tuning fork but not sure) the tuning was simplified. You can use LSB for most ham and USB for the comercial rtty. You may or may not be able to use the narrow filters in the receiver. I don't know exectally how that receiver switches the filers in and out. |
#3
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![]() From: "Ralph Mowery" Organization: EarthLink Inc. -- http://www.EarthLink.net Newsgroups: rec.radio.shortwave,rec.radio.amateur.digital.misc ,rec.ham-radio Date: Sat, 12 Feb 2005 15:49:40 GMT Subject: Rtty Protocol "Greg" wrote in message ... Okay, I have some questions about RTTY: 1. What unencrypted RTTY traffic is out there besides hams? I am not sure about RTTY that is not ham now. I doubt much is in use. There used to be some using other shifts and upside down from the ham standard. You may find a list on rtty.com 2. What sort of encoder would I need to read RTTY with my NRD-525 and what do I need to know to get it functioning? YOu can use your computer with the built in sound card. There are several free programs you can use . MMTTY is a good one to start with. Go here to get the programs. http://www.muenster.de/~welp/sb.htm YOu just hook the sound card input to the speaker or output of the receiver. Even a mic on the computer layed next to the speakers will work in a quiet location. 3. My receiver has an RTTY mode. What exactly does that do in my receiver? Couldn't I just use USB or LSB? The reciever will go to either the LSB or USB mode but the filters will be shifted so they will be centered at higher audio frequencies. The normal ham rtty audio tones are 2125 hz and 2295 hz for the normal 170 hz shift. In real use the receiver could be tuned so that almost any lower frequencies are comming out of the speaker and the demodulator (converter or sound card freqwuencies) set for the lower frequencies. The way it was done in the precomputer days were with fixed filters and it was hard to change the tuning of them. By using lsb and the mark tone of 2125 (think that was a multple of some audio tuning fork but not sure) the tuning was simplified. You can use LSB for most ham and USB for the comercial rtty. You may or may not be able to use the narrow filters in the receiver. I don't know exectally how that receiver switches the filers in and out. Okay, thanks for the info Ralph. I haven't gone to the links yes but I'm betting there's not a lot of RTTY software for my Apple computer. That's why I thought of a standalone decoder, like an MFJ or something. But it's probably not worth the trouble if, as you say, there isn't much RTTY traffic out there. |
#4
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In article ,
Greg wrote: ...I haven't gone to the links yes but I'm betting there's not a lot of RTTY software for my Apple computer. That's why I thought of a standalone decoder, like an MFJ or something. But it's probably not worth the trouble if, as you say, there isn't much RTTY traffic out there. "Multimode OS9 and OS X versions http://www.blackcatsystems.com CocoaModem (new) http://homepage.mac.com/chen/ Good list of software (check datacom/tnc section) at http://www.machamradio.com/HamsAndX.html Mac Ham Software Webring http://w.webring.com/hub?ring=applemacintosham Lots of ham band traffic on RTTY contest weekends. Look into PSK31 as well. -- Chuck Reti WV8A Detroit MI |
#5
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Greg wrote:
From: "Ralph Mowery" Organization: EarthLink Inc. -- http://www.EarthLink.net Newsgroups: rec.radio.shortwave,rec.radio.amateur.digital.misc ,rec.ham-radio Date: Sat, 12 Feb 2005 13:08:16 GMT Subject: Rtty Protocol Most hams are received in the LSB mode. Comercial statisons usually are received in the USB mode or the reversed mark/space relationship. Also the speed (baud rate) and shift are usually differant than the normal ham 45 baud (60 wpm) and 170 Hz shift. "B.R. Smith" wrote in message ... I am using Ham Scope and Mmtty to decode RTTY with my sound card. It works fine for hame radio operators but I have found RTTY on non-ham frquencies and all I get is garbage. For example, there is an RTTY signal at approximately 2.042 MHZ at 1100 UTC on the West Coast and all that displays is random characters. I suspect it has something to do with the protocol or baud rate settings. Anyone know what they might be? Not sure if this is maritime station or not. Thanks. Okay, I have some questions about RTTY: 1. What unencrypted RTTY traffic is out there besides hams? 2. What sort of encoder would I need to read RTTY with my NRD-525 and what do I need to know to get it functioning? 3. My receiver has an RTTY mode. What exactly does that do in my receiver? Couldn't I just use USB or LSB? Thanks, Greg there used to be press services on RTTY. |
#6
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![]() "ryan wiehle" wrote in message ... Greg wrote: there used to be press services on RTTY. The last non-ham RTTY station I remember receiving was a news service for North Korea, years ago. I had a PK-232 TNC, with it's SIAM ( signal identification ) mode that would sniff out the parameters on a mystery signal and attempt to display it for you. It worked pretty well, I thought, decoding oddball digital stuff more often than I expected it to. It was strange to see outdated old Soviet propaganda phrases about "imperialist capitalist dogs" and about how the standard of living in North Korea had gotten so good that they were having to turn Americans immigrants away from the border, seeking asylum. I've looked for - but not found - anything quite so funny and tragic at the same time as that RTTY news service from "the people's democratic republic of Korea" or whatever it was called back then. - It's been a while, I can't remember for sure. Charles Brabham, N5PVL Director: USPacket http://www.uspacket.org Admin: HamBlog.Com http://www.hamblog.com Weblog: http://www.hamblog.com/blog_n5pvl.php |
#7
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You can read that same good ol' commie propaganda online at
http://www.kcna.co.jp/ . -- Tom Sevart N2UHC Frontenac, KS http://www.geocities.com/n2uhc |
#8
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In article ,
Greg wrote: From: "Ralph Mowery" Organization: EarthLink Inc. -- http://www.EarthLink.net Newsgroups: rec.radio.shortwave,rec.radio.amateur.digital.misc ,rec.ham-radio Date: Sat, 12 Feb 2005 13:08:16 GMT Subject: Rtty Protocol Most hams are received in the LSB mode. Comercial statisons usually are received in the USB mode or the reversed mark/space relationship. Also the speed (baud rate) and shift are usually differant than the normal ham 45 baud (60 wpm) and 170 Hz shift. "B.R. Smith" wrote in message ... I am using Ham Scope and Mmtty to decode RTTY with my sound card. It works fine for hame radio operators but I have found RTTY on non-ham frquencies and all I get is garbage. For example, there is an RTTY signal at approximately 2.042 MHZ at 1100 UTC on the West Coast and all that displays is random characters. I suspect it has something to do with the protocol or baud rate settings. Anyone know what they might be? Not sure if this is maritime station or not. Thanks. Okay, I have some questions about RTTY: 1. What unencrypted RTTY traffic is out there besides hams? For 5 bit asynch (start and stop bits using Murray code), not much. There may still be some very cryptic weather reports, and maybe the North Korean news service is still at it. Ex-Soviet maritime traffic uses a code where the Cyrillic charaters are mapped to their close Latin alphabet phonetic matches so you can sort of read it. TOR, (which is actually two different ways of packaging 5 bit RTTY with some error correction), will have some maritime traffic. There are probably FEC-TOR weather reports from the various coast guards around the world on shortwave , and a system that runs down on 512? kHz for maritime information. FEC-TOR is a 100 baud narrow shift continuous transmission. ARQ-TOR is the dREEP-dREEP-dREEP of three character blocks or the 1? character reply from the other station. Hams use half duplex ARQ-TOR where the same frequency is used for both stations, maritime channels are full duplex. 2. What sort of encoder would I need to read RTTY with my NRD-525 and what do I need to know to get it functioning? A lot of the 1980's vintage packet controllers had numerous monitoring modes. I built the Heathkit version of AEA's PK-232 and it will copy RTTY, TOR, AX.25, even weather fax if you have a graphics printer of that vintage. 3. My receiver has an RTTY mode. What exactly does that do in my receiver? Couldn't I just use USB or LSB? Maritime RTTY channels are on .5 kHz spacing, a bit too narrow for a 2 kHz wide USB filter if the band is busy. Mark Zenier Washington State resident |
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