7320khz SSB Oddity?

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simpilo

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First time to catch it. Watch the video. It is only on 7320khz not on other frequencies. It is very strong. It has fading propagation just barely. It is not any devices in my home.
Watch the video see what we can formulate.

 

ratboy

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I wouldn't be surprised if it is an internally generated buzz from the radio itself. Try another receiver and see what is there.
 
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simpilo

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I wouldn't be surprised if it is an internally generated buzz from the radio itself. Try another receiver and see what is there.
Its not generated by the radio. it wasn't on very long. It was only on that frequency.
 

ratboy

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Years ago, I had a "mystery carrier" on my old NRD-515. It annoyed the hell out of me, and I finally put a dead short across the antenna jack and realized it was internal, only in USB mode on a certain freq range on each 1 MHZ "band". Turned out one of the interconnects had oxidized and a little "Deoxit" and soldering the crimped on plugs got rid of the problem. That radio had some odd issues over the almost 30 years I had it, but in general, I loved the thing, and really regretted having to sell it in '13 when I needed cash to pay my bills. That receiver was a killer on RTTY and Digital, and the most pleasurable radio I've ever used. If I lived in a place that wasn't HF RF hell, I would have bought another one, but HF reception is almost impossible here, so what's the point?
nrd.jpg
 

bill4long

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You're not providing much to go on.
What time of the day?
Where are you located?
How often are you hearing it?
What sort of antenna do you have connected to the radio.
Are you near any power lines and/or power transformers.
Are you near any hospitals or medical facilities?
Did you pull the antenna out of the radio and is the noise still there?
Etc etc.
The more data points, the better.

It could be any number of things, including solar generated, but here's a possibility: There is a shortwave station on 7320. Vatican Radio. It's possible that what you're hearing is a signal generator transmitted for the purpose of maintenance or diagnosing a problem with their antenna system. You could write them a email and ask them, if you're interested.
 
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vagrant

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The 7320 kHz frequency is in one of the International broadcast bands. The mode used there is AM, not USB or LSB (SSB).

Still, it may just be the Daleks. There are some strange characters headed to the Hamvention in Xenia.
 

RFI-EMI-GUY

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I agree Bill4Long , Sounds maybe like a ~ 400Hz heavily amplitude modulated tone. They could very well be tuning the TX and antenna system.

Also check harmonics and subharmonics like 7320 X3 = 21,960 and 7320 /3 = 2,440 , and /9 etc.. If you get other hits, it is probably a local interferer. It could be LED lighting or some other nasty device.
 
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simpilo

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I agree Bill4Long , Sounds maybe like a ~ 400Hz heavily amplitude modulated tone. They could very well be tuning the TX and antenna system.

Also check harmonics and subharmonics like 7320 X3 = 21,960 and 7320 /3 = 2,440 , and /9 etc.. If you get other hits, it is probably a local interferer. It could be LED lighting or some other nasty device.

No not a harmonic. I rather believe it was transmitter test but why only in ssb mode and not AM? I will not be over critical of it as it was on for just that little while. I run the same electronics all the time in the same building and that never happened before. If it was a faulty device that buzzing would still be there but that's not the case. Let's not forget it's still shortwave strange things have been known to happen at odd hours of the morning.

I know its not a artifact generated by the radio. I know whre to find it's existing artifacts and I neve rpost about them. It's not RFI from other electronics. I specifically state 0850 UTC in the video. thats 3:50am CDT in Oklahoma
 
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Token

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Man, dealing with a traditional radio for these kinds of signals feels like wearing sunglasses at night, a waterfall display tells you so much more.

Assuming it is not a local signal or RFI:

This appears to be a pulsed signal (a waterfall would make that more clear). As you said there does not appear to be a hetrodyne when you go to SSB and tune across the signal, and while the pitch of the heard signal changes as you tune across it in SSB, the spacing of the harmonics of the pitch do not, the combination of these features strongly suggest pulsed. A strong case for pulsed, but not certain. The tone heard in AM mode (and the harmonic spacing in SSB mode) is the "PRI line" of the pulsed signal, in this case 325 Hz.

Most often such strong pulsed signals on HF are either radars or ionopsheric heaters/experiments (such as Arecibo or HAARP). There can, of course, be other explanations.

In other words, we ain't gonna know from this recording alone.

Is it a radar? Could be. The PRI (Pulse Repetition Interval) used is very close to what is used by several radars, including the Russian Sunflower radar. However, I doubt it would be the Sunflower specifically, as I don't think that is ever heard with that big a signal level on this side of the Atlantic.

Could it be a heater of some kind? Could be. However HAARP is not currently active on a campaign, and while Arecibo is active, the HF components of their testing were not scheduled at that time (the last scheduled HF work before your reported time was at 1300 UTC on May 16, 2019, if they are holding to their published sched) and Arecibo was scheduled to be in the 8 MHz area. So if it was a heater it was probably not one of the two big ones in the region.

At this point, with the supplied data, it is easier to say what it is not, rather than what it is. But I would not rule out a BC transmitter test that involves pulses instead of AM audio.

If you hear it again you may want to try and TDOA it on the Kiwi network, that will give you the location and that could narrow things down a bit.

T!
 
S

simpilo

Guest
Man, dealing with a traditional radio for these kinds of signals feels like wearing sunglasses at night, a waterfall display tells you so much more.

Assuming it is not a local signal or RFI:

This appears to be a pulsed signal (a waterfall would make that more clear). As you said there does not appear to be a hetrodyne when you go to SSB and tune across the signal, and while the pitch of the heard signal changes as you tune across it in SSB, the spacing of the harmonics of the pitch do not, the combination of these features strongly suggest pulsed. A strong case for pulsed, but not certain. The tone heard in AM mode (and the harmonic spacing in SSB mode) is the "PRI line" of the pulsed signal, in this case 325 Hz.

Most often such strong pulsed signals on HF are either radars or ionopsheric heaters/experiments (such as Arecibo or HAARP). There can, of course, be other explanations.

In other words, we ain't gonna know from this recording alone.

Is it a radar? Could be. The PRI (Pulse Repetition Interval) used is very close to what is used by several radars, including the Russian Sunflower radar. However, I doubt it would be the Sunflower specifically, as I don't think that is ever heard with that big a signal level on this side of the Atlantic.

Could it be a heater of some kind? Could be. However HAARP is not currently active on a campaign, and while Arecibo is active, the HF components of their testing were not scheduled at that time (the last scheduled HF work before your reported time was at 1300 UTC on May 16, 2019, if they are holding to their published sched) and Arecibo was scheduled to be in the 8 MHz area. So if it was a heater it was probably not one of the two big ones in the region.

At this point, with the supplied data, it is easier to say what it is not, rather than what it is. But I would not rule out a BC transmitter test that involves pulses instead of AM audio.

If you hear it again you may want to try and TDOA it on the Kiwi network, that will give you the location and that could narrow things down a bit.

T!
Best answer to the unknown Token thanks!

I'll be sure to install a audio spectrum analyzer with a good waterfall on the mobile device. that should provide decent view of the pulses. Whenever and wherever it happens again is beyond me.
 
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Boombox

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Sounds like some kind of RFI.

Also, the 200-629 can have 'birdies', especially when you use an external wire antenna. Mine has one in the upper part of the 31 meter band.
 
S

simpilo

Guest
Man, dealing with a traditional radio for these kinds of signals feels like wearing sunglasses at night, a waterfall display tells you so much more.

Assuming it is not a local signal or RFI:

This appears to be a pulsed signal (a waterfall would make that more clear). As you said there does not appear to be a hetrodyne when you go to SSB and tune across the signal, and while the pitch of the heard signal changes as you tune across it in SSB, the spacing of the harmonics of the pitch do not, the combination of these features strongly suggest pulsed. A strong case for pulsed, but not certain. The tone heard in AM mode (and the harmonic spacing in SSB mode) is the "PRI line" of the pulsed signal, in this case 325 Hz.

Most often such strong pulsed signals on HF are either radars or ionopsheric heaters/experiments (such as Arecibo or HAARP). There can, of course, be other explanations.

In other words, we ain't gonna know from this recording alone.

Is it a radar? Could be. The PRI (Pulse Repetition Interval) used is very close to what is used by several radars, including the Russian Sunflower radar. However, I doubt it would be the Sunflower specifically, as I don't think that is ever heard with that big a signal level on this side of the Atlantic.

Could it be a heater of some kind? Could be. However HAARP is not currently active on a campaign, and while Arecibo is active, the HF components of their testing were not scheduled at that time (the last scheduled HF work before your reported time was at 1300 UTC on May 16, 2019, if they are holding to their published sched) and Arecibo was scheduled to be in the 8 MHz area. So if it was a heater it was probably not one of the two big ones in the region.

At this point, with the supplied data, it is easier to say what it is not, rather than what it is. But I would not rule out a BC transmitter test that involves pulses instead of AM audio.

If you hear it again you may want to try and TDOA it on the Kiwi network, that will give you the location and that could narrow things down a bit.

T!
It returned this morning. Got a waterfall of the audio. This time the signal is much weaker than the first video. definetly NOT local RFI!

 
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Boombox

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Different sound from your first recording.

Good luck in figuring out what it is, though.
 

RFI-EMI-GUY

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It's hard to make out, but there appear to be 5 or 6 tones . Some sort of multi carrier digital modulation. You might want to look up utility stations to see if any are on or near that frequency.

Sent from my SM-T350 using Tapatalk
 
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simpilo

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