riverrat373
Member
Lately I keep hearing what sounds like a beacon on 15.300 USB on the Maritime Mobile Net that I have not heard in the past. Anyone know what I'm hearing?
Beacon?
- Thread starter riverrat373
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W3DMV
Member
I assume you mean 14.300 Mhz in the 20 Meter ham band ? I work that
net several times a week and have never heard a beacon like signal on that
frequency.
Could you elaborate if its a "beeping" sound, recorded voice ? and generally
what time of day ?
net several times a week and have never heard a beacon like signal on that
frequency.
Could you elaborate if its a "beeping" sound, recorded voice ? and generally
what time of day ?
riverrat373
Member
You are right. I miss-typed the frequency! Supposed to be 14.300! It is a beeping sound but right now I do not hear it. ( UTC 2310) I heard it this morning about 0900 local time (PDT). It's not coming from any of my other equipment because I have shut everything down but my receiver to try to isolate the source. It seemed to start about a week ago. I am located in Southwest Washington State and have been monitoring on a Icom IC-R75 with a Jetstream 10-80 meter vertical dipole.
winky6
Member
Im mobile in Denton tx and am picking up that beeping. I have been hearing it myself mostly in the southern states at sporatic times...
Token
Member
Lets see if everyone is on the same page as to what is meant by this beep.
What is the approximate frequency of the beep? If nothing else when tuned to 14300 kHz in USB does it sound high or low pitched?
How often is the beep? If nothing else use a watch and count how many beeps happen in 10 or 15 seconds.
I have at this time a beep that is on a center frequency of 14301.7 kHz. Tuned to 14300 kHz in USB mode that would result in a beep with a pitch of about 1700 Hz. The beep I am hearing is about 0.12 seconds long and happens about every 0.725 seconds, or about 20 times in 15 seconds. It periodically stops, and another sound takes its place for a second or so, sometimes this other sound happens frequently, other times it is many minutes with only the beep present.
If you are hearing the same thing that I am, then what you hear is a Chinese military digital modem.
T!
What is the approximate frequency of the beep? If nothing else when tuned to 14300 kHz in USB does it sound high or low pitched?
How often is the beep? If nothing else use a watch and count how many beeps happen in 10 or 15 seconds.
I have at this time a beep that is on a center frequency of 14301.7 kHz. Tuned to 14300 kHz in USB mode that would result in a beep with a pitch of about 1700 Hz. The beep I am hearing is about 0.12 seconds long and happens about every 0.725 seconds, or about 20 times in 15 seconds. It periodically stops, and another sound takes its place for a second or so, sometimes this other sound happens frequently, other times it is many minutes with only the beep present.
If you are hearing the same thing that I am, then what you hear is a Chinese military digital modem.
T!
AC2OY
Member
That's outstanding! How far away is it from your QTH? What type of radio you have,antenna,power your running...
Token
Member
Hmmm...you responded to me, so I assume those questions are aimed at me maybe? Not really sure how they apply, but OK.
I was talking about receiving an intruder signal in a ham band, in this case a Chinese military modem. I believe that is probably what the other people reporting hearing a beep or beacon were also hearing.
Since we were talking about receiving a signal then power I might be running does not matter, but I do have full legal limit on all HF bands. I used 2 antennas to listen to the intruder, one was a 450 foot Rhombic pointed at China (antenna is pointed 310 deg true from my location), the other was a SteppIR DB36. And two radios were used to look at it, an RFSpace NetSDR and a WinRadio G33DDC. As for how far away...I dunno, but probably some place in China
My QTH is the Mojave Desert, California.T!
majoco
Stirrer
I can just hear him in the mud. CW mode B/W down to 500Hz centre freq . On the waterfall it's possible to see that the dots are irregularly spaced and occasionally there is a series of bursts of data and dashes - the dashes are a bit lower in frequency. He gets obscured by some Spanish speakers adjacent splatter. The signal is above the small grey square on the waterfall.
I see this has already been reported in the "Monitoring Service" of our Ham organisation as an intruder - they say it's a Chinese 75 baud BPSK 16 or 17 tone signal.
G33DDC, OCFD 60ft, 2100z
I see this has already been reported in the "Monitoring Service" of our Ham organisation as an intruder - they say it's a Chinese 75 baud BPSK 16 or 17 tone signal.
G33DDC, OCFD 60ft, 2100z
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Token
Member
Yes, it is a Chinese military 16 Tone PSK modem. What is slightly interesting about this transmission is that while the Chinese tend to like LSB for their military data stuff (for example most Chinese 4+4 modems are LSB) this particular transmission on 14300 kHz is in USB. Most of these 16 tone modems that I see are in LSB also.
T!
AC2OY
Member
Token wow man I think that's really cool! I'm just scratching the surface here with HF I'm like a 50 year old kid in a candy factory when I make a QSO. I have to cut my radio operation down at night due to the fact that my wife can hear me in the basement loud and clear up on the second floor. Might have something due to the ductwork.
winky6
Member
Glad to see i wasnt imaging things when hearing that beep myself. For the record, im using an 857d with an atas 120 ant. I tried a couple times to pick it out while parked, but could never find it. Always came in at odd times while driving.
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