Brazilian here. I saw it on the news some time ago. The police fined some truck drivers because of that. They were basically using it as a long range CB radio.
7:50 Sounds like digital radio transmission. I have digital radios and when you listen on an analog radio at the same frequency you hear this sound. You can also hear it if the antenna is close to a speaker but very faintly (also depends on the type of radio and speaker. The speaker should also be receiving power in standby [without audio])
First guess this would be something DMR or Fusion a-like. I hear the same kind of signals here in amateur band but I'm not sure which one. Interesting video that has some nice samples can be heard here - watch?v=AligJj_G7bg Hope this helps in some way.
Hi Paul! I am an avid listener to this band for many years,here in Florida where I live near Tampa. The band you are listening to is allocated to military satelites, the old Fleetsatcom is in the 262 mhz area. I do not hear those digital sigs here which makes me think these are images of other freqs sounds like p25 digital data control signals in your area. If it were actual satelite sigs the signal would come snd go as they are FMn emissions. Most of what you will hear are illegal use of the Satelites from Brazil Portugese language I believe . Tim kg4jjs
I don't know what the signals are, but for the 262MHz set, I was surprised that when you inserted the 10 & 20dB attenuators there was no visible difference in the noise floor that stayed at about -104dBm. Is this what you expect? When I try adding attenuators (at least on HF), the noise floor drops by a similar amount to the signal.
@@BrianG61UK Ah, thanks for answering this. I've only used my SDR on the HF bands and hadn't experienced this for myself, although I did wonder whether this could be the case as I typed the comment! Cheers.
Yes exactly.. With the poor antenna I was using the RX noise floor is far below the that of antenna. Unlike HF where atmospheric noise is many DB higher
Ai (chatGPT-4) said: "One of the possible sources of digital signals in this scope can be the Land Mobile Radio Service (LMRS), which is used by public services, industrial and business organizations for communication between users within a local or regional area. This system is often used by firefighters, EMS, police and other public services. Another possible source may be a military radio system. In the US, the military uses the VHF band for tactical communications, and frequencies near 262 MHz may be part of such a system. The military often uses digital signals for better connection quality, immunity to interference and encryption capabilities."
Have you tried a different receiver? That sounds like P25 and other digital radio from the 700 and 800 MHz band. Could just be a flaw in the SDR you're using.
Just subscribed. Completely ignorant regarding radio. I subscribe to the collapse of civilization. I have been told to look into SW and VHF. Would you recommend a decent radio? To receive. And antenna recommendations. Thanks very much!
Sounds like Motorola DMR on 262MHz. Compare it to the digital 2m or 70cm digital repeaters in your area if you have one. DMR can be encryptet. I find it sounds exactly like those repeaters. Im in europe though and dont know if you have any digital ham radio repeaters.
You know what W1VLF I think this is a microwave auditory effect signal I've been picking up these radio frequencies that look extremely similar to that on my software defined radio and it was actually pulsed radio frequency so strong and in a specific way that was creating the Frey effect phenomenon, i shit you not
Definitely seems like speech inside it i've handled similar freq coming into my house creating mae and frey effect and it looked just like that except stronger and when i used filters i found the hidden communication inside it.... sounds like sci-fi but this is real i promise
Hi, i may be stating the obvious here but, that just looks like DMR control channel, and all those other poping back and forth downlinks are voice channels... You can try to decode them with DSDplus... -NH2OD 73.
You know what W1VLF I think this is a microwave auditory effect signal I've been picking up these radio frequencies that look extremely similar to that on my software defined radio and it was actually pulsed radio frequency so strong and in a specific way that was creating the Frey effect phenomenon, i shit you not
Brazilian here. I saw it on the news some time ago. The police fined some truck drivers because of that. They were basically using it as a long range CB radio.
7:50 Sounds like digital radio transmission. I have digital radios and when you listen on an analog radio at the same frequency you hear this sound. You can also hear it if the antenna is close to a speaker but very faintly (also depends on the type of radio and speaker. The speaker should also be receiving power in standby [without audio])
sounds like ordinary DMR. you can try to use some free software decoder to look what ius transmitting there.
That is what I am trying right now.. Thank you W1VLF
@@W1VLF it will be interesting to see after decoding what happens there on that satellite :)
@@W1VLF btw. i can suggest you "dsd+ fast lane" as an example of free soft for decoding.
@@Alximiks Thanks for the software suggestion.. Right now I am trying SDR Angel with limited success...
@@Alximiks Thank you.. I am having a problem configuring any type of software I try. It is very confusing to an old Analog guy like myself
Did you try some WEB SDR in the US , just to compare.
..that digi sounds like MSK144 which is used on 6 and 2m for meteor scatter..During the 6m season, you will hear strong MSK144 around 50.260...
First guess this would be something DMR or Fusion a-like. I hear the same kind of signals here in amateur band but I'm not sure which one.
Interesting video that has some nice samples can be heard here - watch?v=AligJj_G7bg
Hope this helps in some way.
Hi Paul! I am an avid listener to this band for many years,here in Florida where I live near Tampa. The band you are listening to is allocated to military satelites, the old Fleetsatcom is in the 262 mhz area. I do not hear those digital sigs here which makes me think these are images of other freqs sounds like p25 digital data control signals in your area. If it were actual satelite sigs the signal would come snd go as they are FMn emissions. Most of what you will hear are illegal use of the Satelites from Brazil Portugese language I believe . Tim kg4jjs
Hi Tim, Thanks for the input. I tried to email you with QRZ email address to see if we could talk about this more.
If you have any means of receiving Inmarsat signals, you will find encrypted signals which look and sound exactly the same.
I don't know what the signals are, but for the 262MHz set, I was surprised that when you inserted the 10 & 20dB attenuators there was no visible difference in the noise floor that stayed at about -104dBm. Is this what you expect? When I try adding attenuators (at least on HF), the noise floor drops by a similar amount to the signal.
That's the normal difference between HF and VHF/UHF.
@@BrianG61UK Ah, thanks for answering this. I've only used my SDR on the HF bands and hadn't experienced this for myself, although I did wonder whether this could be the case as I typed the comment! Cheers.
Yes exactly.. With the poor antenna I was using the RX noise floor is far below the that of antenna. Unlike HF where atmospheric noise is many DB higher
3rd order intermod will drop 3dB per 1dB of attenuation.
Ai (chatGPT-4) said: "One of the possible sources of digital signals in this scope can be the Land Mobile Radio Service (LMRS), which is used by public services, industrial and business organizations for communication between users within a local or regional area. This system is often used by firefighters, EMS, police and other public services.
Another possible source may be a military radio system. In the US, the military uses the VHF band for tactical communications, and frequencies near 262 MHz may be part of such a system. The military often uses digital signals for better connection quality, immunity to interference and encryption capabilities."
Have you tried a different receiver? That sounds like P25 and other digital radio from the 700 and 800 MHz band. Could just be a flaw in the SDR you're using.
Just subscribed. Completely ignorant regarding radio. I subscribe to the collapse of civilization. I have been told to look into SW and VHF. Would you recommend a decent radio? To receive. And antenna recommendations. Thanks very much!
Sounds like Motorola DMR on 262MHz. Compare it to the digital 2m or 70cm digital repeaters in your area if you have one. DMR can be encryptet. I find it sounds exactly like those repeaters. Im in europe though and dont know if you have any digital ham radio repeaters.
Yes it is.. I am learning about this stuff Thank you
You know what W1VLF I think this is a microwave auditory effect signal I've been picking up these radio frequencies that look extremely similar to that on my software defined radio and it was actually pulsed radio frequency so strong and in a specific way that was creating the Frey effect phenomenon, i shit you not
sounds just like p25p1. there was software used with unitrunker i cant remember the name. it would decode p25p1.
No Web SDR tuneable to this frequency .
freedv?
I'm hearing analog voice narrowband FM 257.04
Definitely seems like speech inside it i've handled similar freq coming into my house creating mae and frey effect and it looked just like that except stronger and when i used filters i found the hidden communication inside it.... sounds like sci-fi but this is real i promise
Hi, i may be stating the obvious here but, that just looks like DMR control channel, and all those other poping back and forth downlinks are voice channels...
You can try to decode them with DSDplus...
-NH2OD 73.
It sounds just like DMR or P25 to me.
Yes it does.. I am trying my hand and DMR and digital decoding thank you W1VLF
@@W1VLF It's pretty simple using SdrAngel with the DSD plugin ;)
th-cam.com/video/I2mWNxgZr2A/w-d-xo.html
@@MI7DJT I wish it was easy.. I am having trouble configuring the software correctly... Any suggestions where to look for info on this?
@@W1VLF I just used videos on youtube and fiddled with settings until I got it. Everyone's setup will differ so it's really trial and error.
Scrambling-- morse code.. the usual!
You know what W1VLF I think this is a microwave auditory effect signal I've been picking up these radio frequencies that look extremely similar to that on my software defined radio and it was actually pulsed radio frequency so strong and in a specific way that was creating the Frey effect phenomenon, i shit you not