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#1
January 14th 10, 07:40 PM
posted to rec.radio.shortwave
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AM 3 Mhz ?
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#2
January 14th 10, 08:08 PM
posted to rec.radio.shortwave
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AM 3 Mhz ?
"François Guillet" wrote in message
... Here is a much better record: http://exvacuo.free.fr/div/Radio/Arc...%203093Khz.mp3 Are they definitely double sideband AM and not SSB with a carrier? -- Brian Gregory. (In the UK) To email me remove the letter vee. |
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#3
January 15th 10, 08:42 AM
posted to rec.radio.shortwave
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AM 3 Mhz ?
On Jan 14, 2:08*pm, "Brian Gregory [UK]" wrote:
"François Guillet" wrote in message ... Here is a much better record: http://exvacuo.free.fr/div/Radio/Arc...Divers/AM%2030... Are they definitely double sideband AM and not SSB with a carrier? -- Brian Gregory. (In the UK) To email me remove the letter vee. Well, this not pure traditional AM. And as far as I can discern it is not regular SSB either ! Is this DSB-AM with reduced or suppressed carrierier , or is this SSB plus+ a reduced carrier? Signal is not very stable, modulation seems to jump up and down constantly. Need to switch to another agc setting,if possible. This last recording is much better than the first and second. May be, if I hear a longer transmission they will accidentally give away who the hell they are. Judging from one party being much, much louder the other fellow may be situated very far away. This is not your standard literary language,either. Lots of uncensored expressions. Frequencies are really baffling me. Still think it is an intermodulation product. What receiver is being used? |
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#5
January 15th 10, 10:13 PM
posted to rec.radio.shortwave
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AM 3 Mhz ?
a écrit dans le message de news:
... On Jan 14, 2:08 pm, "Brian Gregory [UK]" wrote: "François Guillet" wrote in message ... Here is a much better record: http://exvacuo.free.fr/div/Radio/Arc...Divers/AM%2030... Are they definitely double sideband AM and not SSB with a carrier? -- Brian Gregory. (In the UK) To email me remove the letter vee. | Well, this not pure traditional AM. And as far as I can discern | it is not regular SSB either ! Is this DSB-AM with reduced or | suppressed carrierier , or is this SSB plus+ a reduced carrier? | Signal is not very stable, modulation seems to jump up and down | constantly. Need to switch to another agc setting,if possible. This | last recording is much better than the first and second. May be, if I | hear a longer transmission they will accidentally give away who the | hell they are. Judging from one party being much, much louder the | other fellow may be situated very far away. This is not your standard | literary language,either. Lots of uncensored expressions. Frequencies | are really baffling me. Still think it is an intermodulation product. | What receiver is being used? The receiver is an old transceiver Icom IC751. I have added an interface that converts IF signal at 455 Khz down to 12 Khz then the 12 Khz signal is connected to my PC sound card (band pass is around 15-20 Khz). I use Dream software for demodulating the signal. Dream was firstly intended to decode DRM but its last version can also handle AM, SSB, CW and FM. In Dream one can adjust a filter to match the received signal. I choose the band pass for the best subjective audio. Dream records the demodulated signal in .wav files. After recording the russian stations, I used Adobe Audition for processing operations of noise reduction, clics removing and MP3 conversion. It is not DSB AM or SSB+carrier. It is real AM with the two side bands. Some stations have a frequency shifted by the modulation. It looks like old TX with VFO pilot (not synthetized). QSB is probably the cause of carrier fading and modulation distorsion. Some other samples but not good, band is very noisy, transmissions are not very long (1mn max), with long pauses so it is difficult to monitor them: http://exvacuo.free.fr/div/Radio/Arc...ussian%201.mp3 http://exvacuo.free.fr/div/Radio/Arc...ussian%202.mp3 http://exvacuo.free.fr/div/Radio/Arc...ussian%203.mp3 |
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#6
January 16th 10, 08:37 AM
posted to rec.radio.shortwave
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AM 3 Mhz ?
On Jan 15, 4:13*pm, "François Guillet"
wrote: a écrit dans le message de news: ... On Jan 14, 2:08 pm, "Brian Gregory [UK]" wrote: "François Guillet" wrote in message ... Here is a much better record: http://exvacuo.free.fr/div/Radio/Arc...Divers/AM%2030.... Are they definitely double sideband AM and not SSB with a carrier? -- Brian Gregory. (In the UK) To email me remove the letter vee. | * Well, this not pure traditional AM. And *as far as I can discern | it is not regular SSB either ! * Is this DSB-AM *with reduced or | suppressed carrierier , or is this SSB plus+ a reduced carrier? | Signal is not very stable, modulation seems to jump up and down | constantly. Need to switch to another agc setting,if possible. *This | last recording is much better than the first and second. May be, if I | hear a longer transmission they will *accidentally give away *who the | hell they are. Judging from one party being much, much louder the | other fellow may be situated very far away. This is not your standard | literary language,either. *Lots of uncensored expressions. Frequencies | are really baffling me. Still think it is an intermodulation product. | What receiver is being used? The receiver is an old transceiver Icom IC751. I have added an interface that converts IF signal at 455 Khz down to 12 Khz then the 12 Khz signal is connected to my PC sound card (band pass is around 15-20 Khz). I use Dream software for demodulating the signal. Dream was firstly intended to decode DRM but its last version can also handle AM, SSB, CW and FM. In Dream one can adjust a filter to match the received signal. I choose the band pass for the best subjective audio. Dream records the demodulated signal in .wav files. After recording the russian stations, I used Adobe Audition for processing operations of noise reduction, clics removing and MP3 conversion. It is not DSB AM or SSB+carrier. It is real AM with the two side bands. Some stations have a frequency shifted by the modulation. It looks like old TX with VFO pilot (not synthetized). QSB is probably the cause of carrier fading and modulation distorsion. Some other samples but not good, band is very noisy, transmissions are not very long (1mn max), with long pauses so it is difficult to monitor them:http://exvacuo.free.fr/div/Radio/Arc...Divers/AM%20Ru... If this was back 20+ years ago, I would say it could be some sort of high seas radiotelephone transmissions. Only one side of the conversation is heard in general. But, majority of them, (practically all) were in USB as a rule. The other party has almost always used another frequency. None of the offical radiotelephone transmissions were so brief. None of the official operators spoke with such a hurry. The s/n ratio is very poor. Power levels seem to be very low and transmitters don't sound stable enough for reliable communication . If it is not maritime traffic, it may be something different. Bootleggers, pirates, or traffickers of some sort probably. May be we can use D/F them,or establish some pattern .What time of day or night do they pop- up? |
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#7
January 16th 10, 04:38 PM
posted to rec.radio.shortwave
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AM 3 Mhz ?
a écrit dans le message de news: ... On Jan 15, 4:13 pm, "François Guillet" wrote: .... It is not DSB AM or SSB+carrier. It is real AM with the two side bands. Some stations have a frequency shifted by the modulation. It looks like old TX with VFO pilot (not synthetized). QSB is probably the cause of carrier fading and modulation distorsion. Some other samples but not good, band is very noisy, transmissions are not very long (1mn max), with long pauses so it is difficult to monitor them:http://exvacuo.free.fr/div/Radio/Arc...les/Divers/AM% 20Ru...http://exvacuo.free.fr/div/Radio/Arc...les/Divers/AM% 20Ru...http://exvacuo.free.fr/div/Radio/Arc...Divers/AM%20Ru... | If this was back 20+ years ago, I would say it could be | some sort of high seas radiotelephone transmissions. Only one side of | the conversation is heard in general. But, majority of them, | (practically all) were in USB as a rule. The other party has almost | always used another frequency. None of the offical radiotelephone | transmissions were so brief. None of the official operators spoke with | such a hurry. The s/n ratio is very poor. Power levels seem to be very | low and transmitters don't sound stable enough for reliable | communication . Yes it sounds like transmissions in the 60's. Nevertheless I don't think they come from break in space-time :-) My location is possibly at 4000-8000 kms from these stations. This explains the weak signals. Signals from russian ham stations are not much stronger here on 80 mtrs (but SBB modulation is much better and also 3.6 Mhz is less noisy). | If it is not maritime traffic, it may be something | different. Bootleggers, pirates, or traffickers of some sort | probably. May be we can use D/F them,or establish some pattern .What | time of day or night do they pop- up? I receive them weekdays and weekend every evening from around 17h-18h to 23h UTC (not tried later, time to sleep). It is probably not their full period of activity but the time at which the 3 Mhz band is open between France and Russia. |
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#8
January 17th 10, 06:03 AM
posted to rec.radio.shortwave
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AM 3 Mhz ?
On Jan 16, 10:38*am, "François Guillet"
wrote: a écrit dans le message de news: ... On Jan 15, 4:13 pm, "François Guillet" wrote: ... It is not DSB AM or SSB+carrier. It is real AM with the two side bands. Some stations have a frequency shifted by the modulation. It looks like old TX with VFO pilot (not synthetized). QSB is probably the cause of carrier fading and modulation distorsion. Some other samples but not good, band is very noisy, transmissions are not very long (1mn max), with long pauses so it is difficult to monitor them:http://exvacuo.free.fr/div/Radio/Arc...les/Divers/AM% 20Ru...http://exvacuo.free.fr/div/Radio/Arc...les/Divers/AM% 20Ru...http://exvacuo.free.fr/div/Radio/Arc...Divers/AM%20Ru... | * * * * * * * If this was back 20+ years ago, I would say it could be | some sort of high seas radiotelephone transmissions. Only one side of | the conversation is heard in general. But, majority of them, | (practically all) were in USB as a rule. The other *party has almost | always used another frequency. None of the offical radiotelephone | transmissions were so brief. None of the official operators spoke with | such a hurry. The s/n ratio is very poor. Power levels seem to be very | low and transmitters don't sound stable enough *for reliable | communication . Yes it sounds like transmissions in the 60's. Nevertheless I don't think they come from break in space-time :-) My location is possibly at 4000-8000 kms from these stations. This explains the weak signals. Signals from russian ham stations are not much stronger here on 80 mtrs (but SBB modulation is much better and also 3.6 Mhz is less noisy). | If it is not maritime traffic, it may be something | different. Bootleggers, pirates, or traffickers of some sort | probably. *May be we can use D/F them,or establish some pattern .What | time of day or night do they pop- up? I receive them weekdays and weekend every evening from around 17h-18h to 23h UTC (not tried later, time to sleep). It is probably not their full period of activity but the time at which the 3 Mhz band is open between France and Russia. For some reason I still have doubts of using of 3MHz band as a reliable long distance 2-way choice . Ex navy /merchant marine personnel turned into pirates/smugglers, perhaps. Low budget = poor radio equipment. Lots of fowl language. Cannot be official business, as far as I am concerned. Their transmissions a way too short. 3 MHz band has not been used by anyone in years (on a regular basis). It was never stable even at night,and especially now, with such minimal sunspot number. The operating frequencies seem to be floating, this is not typical of any regular business I can think of. And they ALL transmit only in AM? Big mystery. |
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