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Author Topic: DX VK land LF 2200m amateur band propagation  (Read 2002 times)

sdruzer

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DX VK land LF 2200m amateur band propagation
« on: April 06, 2020, 0346 UTC »
I was conflicted whether to post this in the amateur section or this one, so the admin is free to move it.

Anyway... just thought I'd mention that the season for long distance copy on lf is growing short because of the increased noise level here in NA. Spring is here and storms are getting frequent. However, there are still some good nights that allow decent decoding of some long-haul distant lf signals. I'm refering specifically to Trans-Pacific copy from Australia to the CONUS on the 2200m lf band. Station VK4YB can still be decoded here (not every night of course) in NA using the wspr2 mode of transmission in the wee hours of the morning. 

It's a real challenge to copy sigs that far away, at amateur legal power levels at that freq. Your rx station has to contend with noise-makers in your own household, as well as the neighbors, and noise from the utility powerlines... but it can be done. If you're already familiar with LW reception techniques, you may wish to give the 2200m band a try for a new challenge. Besides the dx, there are a few stations in the CONUS on every night using wspr2 mode. You can see how well your rx station is performing in general by how well you can copy those stations.

p.s. The decoder software is wsjt-x and your rcvr is set at 136 khz usb to decode in wspr2 mode.

UPDATE:  April 17, 2020

Listed are the overnight wspr2 decodes of VK4YB in the CONUS. Good to see the LF dx season still extending this late in the year, even with Spring QRN.

 2020-04-17 10:52     VK4YB     0.137557     -29     0     QG62ku     1     SWLEM3     EM03rf     13250     65
 2020-04-17 10:54     VK4YB     0.137557     -27     0     QG62ku     1     SWLEM3     EM03rf     13250     65
 2020-04-17 11:02     VK4YB     0.137557     -27     0     QG62ku     1     SWLEM3     EM03rf     13250     65
 2020-04-17 11:06     VK4YB     0.137557     -27     0     QG62ku     1     SWLEM3     EM03rf     13250     65
 2020-04-17 11:12     VK4YB     0.137557     -31     0     QG62ku     1     SWLEM3     EM03rf     13250     65
 2020-04-17 11:14     VK4YB     0.137557     -29     0     QG62ku     1     SWLEM3     EM03rf     13250     65
 2020-04-17 11:18     VK4YB     0.137557     -28     0     QG62ku     1     SWLEM3     EM03rf     13250     65
 2020-04-17 11:42     VK4YB     0.137557     -33     0     QG62ku     1     W7IUV             DN07dg     12002     45
 2020-04-17 10:54     VK4YB     0.137557     -31     0     QG62ku     1     N6LF             CN83lt     11615     48
 2020-04-17 11:34     VK4YB     0.137557     -27     0     QG62ku     1     N6LF             CN83lt     11615     48
 2020-04-17 11:36     VK4YB     0.137557     -30     0     QG62ku     1     N6LF             CN83lt     11615     48
 2020-04-17 11:40     VK4YB     0.137557     -29     0     QG62ku     1     N6LF             CN83lt     11615     48
 2020-04-17 11:46     VK4YB     0.137557     -32     0     QG62ku     1     N6LF             CN83lt     11615     48
 2020-04-17 12:46     VK4YB     0.137557     -25     0     QG62ku     1     N6LF             CN83lt     11615     48
 2020-04-17 12:48     VK4YB     0.137557     -26     0     QG62ku     1     N6LF             CN83lt     11615     48
 2020-04-17 12:52     VK4YB     0.137557     -27     0     QG62ku     1     N6LF             CN83lt     11615     48



« Last Edit: April 17, 2020, 1452 UTC by sdruzer »

Offline NJQA

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Re: LF 2200m amateur band propagation
« Reply #1 on: April 06, 2020, 1224 UTC »
The KiwiSDR built-in WSPR decoder includes a setting for the 2200M band.  I have heard a few stations here, but not as many as I have heard on 630M.
« Last Edit: April 07, 2020, 1108 UTC by NJQA »

sdruzer

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Re: LF 2200m amateur band propagation
« Reply #2 on: April 06, 2020, 1339 UTC »
NJQA, you're right about the 630m band having much more activity than 2200m. It's more of a challenge to not only rx well on that band, but to tx also. Since the antenna efficiency is very low due to the longer wavelength, one must use good materials in antenna construction. Corona can damage insulators, as well as the transmitter when the swr gets out of hand. Good protection circuits are a must.

I look at 2200m as a challenge. It tests the skills of the op whether tx'ing or refining your rx equipment to dig into the noise level to decode that distant station.

Offline Pigmeat

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Re: LF 2200m amateur band propagation
« Reply #3 on: April 06, 2020, 2350 UTC »
The folks at Monitoring Times printed a SSB/CW schematic for a LW tx when it became clear the bands were going to be opened for HAM use.The problem was the FCC was concerned one of them would actually be heard, so they screwed with the antenna regs for years.

sdruzer

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Re: LF 2200m amateur band propagation
« Reply #4 on: April 07, 2020, 0201 UTC »
Well, it took years to finally get everything hammered out, but at least the bands are open and the limiting tx factor is EIRP. Regardless, a number of stations are having success on the band... covering some good distances. Besides wspr2, occasionally stations will use JT9 for two-way qso's. I've also seen some QRSS beaconing at times.

 

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