ka3jjz
Wiki Admin Emeritus
From Martin in SW UK via the UDXF reflector - as always, any transcription errors are entirely mine....
John Seamons, the KiWi SDR developer has just released a test version of HFDL decoder extension on KiWi sdr's that are running software version v1.472 or higher. Note that this has only just been released, so it may take a few days for all KiWi's to become updated.
To find the HFDL decoder open up the 'Extensions' dropdown at the top of the 'pop out ' control panel in the bottom right hand corner of the display and select 'HFDL'
Some further guidance notes coped from the KiWi forum.
"There are definitely some problems with the extension. But I wanted to make it available on more Kiwis to make testing easier. In particular there seems to be trouble getting any message decodes initially. For stubborn cases re-opening the extension and clicking the "test" button until you get a decode helps. There may also be issues when multiple channels are running the extension although it works fine in some cases.
Since the EiBi database has labels for most of the HFDL channels a good way to visualize activity on a particular band is to switch to using EiBi (control backslash), select only HFDL, and adjust the zoom until all the HFDL labels of that band fit the waterfall. This makes it easy to see which channels have activity. Then you can shift-click a particular HFDL label to bring up the extension on that channel. Shift-click on other labels or use the HFDL extension menus from there.
The "display" menu changes the format of the decoded messages displayed. "DX" shows an abbreviated two-line message per transmission (similar to the ALE 2G extension). "Squitter" is an HFDL term for ground stations transmitting the dynamic "active frequency table" (AFT). Squitter mode will limit the messages to the AFT so it's easier to see which ground stations are using what frequencies.
You might also want to reduce the waterfall update rate to "slow" so that you can see more evidence of channel transmission.
The help button has more information on URL parameters. So a compact URL to monitor a particular band might be: my_kiwi:8073/?f=z7&dx=none,hfdl&ext=hfdl,8977,d:1,l:10&wf=s Adjust as required.
A Kiwi that has poor frequency calibration (because it's not using GPS correction and is in a particularly cold/warm room) will exceed the ability of the HFDL decoder to lock to the signal. This has been observed. In the absence of GPS you can do a Kiwi manual frequency calibration against a time station (e.g. WWV/H, BPC etc.) as described in the Kiwi documentation. The header of each HFDL message (highlighted in yellow) shows the frequency correction. Anything more than about 50 Hz won't decode."
I've tried the decoder and for a beta test version it seems to work pretty well, with plenty of downlink signals from aircraft decoded in addition to uplinks from ground stations.
Try this link to one of my KiWi's.
http://websdr.uk:8060/?ext=hfdl
=============
If there are any Kiwi SDRs that aren't using the EiBi database, you can find a list of HFDL stations and frequencies here
Mike
John Seamons, the KiWi SDR developer has just released a test version of HFDL decoder extension on KiWi sdr's that are running software version v1.472 or higher. Note that this has only just been released, so it may take a few days for all KiWi's to become updated.
To find the HFDL decoder open up the 'Extensions' dropdown at the top of the 'pop out ' control panel in the bottom right hand corner of the display and select 'HFDL'
Some further guidance notes coped from the KiWi forum.
"There are definitely some problems with the extension. But I wanted to make it available on more Kiwis to make testing easier. In particular there seems to be trouble getting any message decodes initially. For stubborn cases re-opening the extension and clicking the "test" button until you get a decode helps. There may also be issues when multiple channels are running the extension although it works fine in some cases.
Since the EiBi database has labels for most of the HFDL channels a good way to visualize activity on a particular band is to switch to using EiBi (control backslash), select only HFDL, and adjust the zoom until all the HFDL labels of that band fit the waterfall. This makes it easy to see which channels have activity. Then you can shift-click a particular HFDL label to bring up the extension on that channel. Shift-click on other labels or use the HFDL extension menus from there.
The "display" menu changes the format of the decoded messages displayed. "DX" shows an abbreviated two-line message per transmission (similar to the ALE 2G extension). "Squitter" is an HFDL term for ground stations transmitting the dynamic "active frequency table" (AFT). Squitter mode will limit the messages to the AFT so it's easier to see which ground stations are using what frequencies.
You might also want to reduce the waterfall update rate to "slow" so that you can see more evidence of channel transmission.
The help button has more information on URL parameters. So a compact URL to monitor a particular band might be: my_kiwi:8073/?f=z7&dx=none,hfdl&ext=hfdl,8977,d:1,l:10&wf=s Adjust as required.
A Kiwi that has poor frequency calibration (because it's not using GPS correction and is in a particularly cold/warm room) will exceed the ability of the HFDL decoder to lock to the signal. This has been observed. In the absence of GPS you can do a Kiwi manual frequency calibration against a time station (e.g. WWV/H, BPC etc.) as described in the Kiwi documentation. The header of each HFDL message (highlighted in yellow) shows the frequency correction. Anything more than about 50 Hz won't decode."
I've tried the decoder and for a beta test version it seems to work pretty well, with plenty of downlink signals from aircraft decoded in addition to uplinks from ground stations.
Try this link to one of my KiWi's.
http://websdr.uk:8060/?ext=hfdl
=============
If there are any Kiwi SDRs that aren't using the EiBi database, you can find a list of HFDL stations and frequencies here
Mike
