HFU HF Underground
Loggings => Other => Topic started by: tybrad on April 05, 2014, 0008 UTC
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Strange tones on 7080 (+/-) kHz on CW and sounds like two sets of them at times; and S5-9, depending. The transmission comes on, plays its diddy (which is not the same every time), then stops for 5 secs and then begins again.
What is this? Global Freq Database did not help.
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hi, just listening to the frequency what you are hearing is jt-65a digital signals.
chuck
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Thanks chucks. What is their use/origin?
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I forgot one mode in there, it was Olivia. They are ham digital modes, jt-65a is used for very low power world wide communications.
The signal can be down in the noise but you still get 100% copy. It started out being used on 144 and 432 mhz for moon bounce.
The have since adapted for HF use.
Chuck
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Strange tones on 7080 (+/-) kHz on CW and sounds like two sets of them at times; and S5-9, depending. The transmission comes on, plays its diddy (which is not the same every time), then stops for 5 secs and then begins again.
What is this? Global Freq Database did not help.
As chucks said, it is most likely JT65a. When you hear a tune that reminds you a little of an Ice Cream truck that is often JT65a.
The Global Freq DB is not going to be much help here because this is inside the ham 40 meter band. In that (and all) ham band there is no real way to list what you might hear on what frequency. Sure, the bands are broken up into CW, Data, and Voice sections, but different regions put those in different frequency ranges. And even then, you could hear CW in any segment of the band.
Here is the US ham band breakdown, other nations/regions are similar but may not be exactly the same:
http://www.arrl.org/files/file/Regulatory/Band%20Chart/Hambands_color.pdf
Since the intercept is not a beacon I am going to move this thread to the “Other” forum.
T!