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>Almost a year old now (October 2009), but in the interest of adding >content, here is something I wrote. I originally sent it to the ENIGMA2000 >group, so >that's why you'll see references to "e2kfiles." > > > Information on V2a/M8a/SK01/Radio Habana Cuba ringing sound >I use a Ten-Tec RX320D and an indoor antenna that is a few feet longer >than 100 feet (30.48 meters) and used Baudline ( http://www.baudline >.com/) for analysis of the frequencies and tone length. > >Ringing: >Ring high tone : 777.10 Hz >Ring low tone : 621.83 Hz >Ring tone length : 0.0700 Seconds >Ring tone High-Low cycle length : 0.1400 Seconds >Ring High-Low rate : 7.1428571 Hz > >Unknown low tone : 466.55 Hz > >[Note: Frequencies and times were measured with a cheap internal sound >card. They are probably not totally accurate.] > >With this information, I've made a simulation of the ringing. It is >available here: http://eepromeagle.dyndns.org/e2kfiles/ringsimulation.wav > >The ringing will sometimes be longer or shorter than usual. However, I >have not checked the length of each ring to see if a certain ring length >corresponds to a certain number (like the XP stations, but with time >instead of frequency). >By ear, the tones themselves seem to stay pretty much constant in length >somewhere near the measured 0.0700 second length, and it's the number of >times the high-low (or low-high) cycles repeat that changes. Listening to >my recordings, in one of the rings, the length of the first tone in the >ring sounds like it is shorter. I'm not sure if this was an error when I >was recording or if it really was shorter. > >There is often a really low tone (the "Unknown low tone" as specified >above) that is sometimes present with the ringing and will sometimes stop >and start. This could be just RFI, but I thought it'd be worth mentioning. > >I saw something about this on the list, but on 2009-10-21 at 04:48UTC on >6000kHz, I heard the same ringing sound on Radio Habana Cuba. I made two >recordings of that: >http://eepromeagle.dyndns.org/e2kfiles/RHCwRing-6000kHzAM-20091021-0448UTC.wav >and >http://eepromeagle.dyndns.org/e2kfiles/RHCwRing-6000kHzAM-20091021-0455UTC.wav >. > >I also made a good recording of SK01 with very loud ringing (some QRM >though) on 2009-10-13 at 09:33UTC on 5930kHz AM, which you can find here: >http://eepromeagle.dyndns.org/e2kfiles/SK01-5930kHzAM-20091013-0933UTC.wav >(warning : it is almost 150MB. I recorded it with a sample rate of 48000 >kHz even though I was using a filter that appears to filter off anything >above 4.5kHz) >I might have recorded it in SSB and forgot to change the filename (my >radio is around 53Hz off frequency in SSB without correction). I think I >had the radio tuned somewhere around 53Hz below 5930kHz to correct for >inaccuracy though. > >Here is another one with loud ringing as well as the low tone (you can >hear it make a "dah-dit-dah" noise near the middle) 2009-10-13 at 09:32UTC >on 5947kHz LSB: >http://eepromeagle.dyndns.org/e2kfiles/SK01-5947kHzLSBaAM-20091013-0932UTC.wav >I did switch modes near the middle of the recording, so there are some >loud beeps. It was recorded in LSB, not sure if I corrected it or not. > >I may have written down the frequencies and times incorrectly for the >recordings since I probably mistyped some of the filenames. I normally >keep logs with accurate data that are separate from the recordings, but >when trying to switch frequencies and start more recordings fast, it was >kind of easy to make mistakes. Hi Nick, I can confirm the ring tones in all of your recordings, where you gave us the links of. Also the simulation were exactly the same tones as in the original recordings. Did you also notice this ringing on V02a and M08a? And does it still ring, or was it only in October 2009? 73 Jochen Kopf, ENIGMA2000 ______________________________________________________________ Spooks mailing list Home: http://mailman.qth.net/mailman/listinfo/spooks Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Spooks@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
