开云体育

开云体育

Patricia,

The vagaries of HF propagation may be at work, here.

1) When you go to any band on your IC-7300, you should see activity in the FT8 channel.? If not, then the band for your location is really closed, as I've found that FT8 activity is about the last to go as a band shuts down.? The FT8 frequencies on the HF bands are:

• 160m 1.84 MHz
• 80m? ?3.573 MHz
• 40m? ?7.074 MHz
• 30m 10.136 MHz
• 20m 14.074 MHz
• 17M 18.1 MHz
• 15M 21.074 MHz
• 12M 24.915 MHz
• 10M 28.074 MHz
• 6M? ?50.313 MHz

all on USB/Digital, 4 kHz bandwidth channels.? You'll notice that for all the non-WARC bands 40m, 20m, 15m, and 10M, the FT8 channel is always 74 kHz from the bottom of the band.

I purposefully left 60m out, as it is technically illegal to use FT8 on 60m, unless you lock your transmit frequency to 1500 Hz above your dial frequency, centering it in the 2.8 kHz passband, which is required for CW or any digital modes on 60m.? That means that everyone would be piling on the same offset, which makes it difficult to make any contacts on 60m if the frequency is congested.? Of course, there are a great many miscreants that are using the whole 2.8 kHz channel there for FT8, but I would advise against it, as various government services share those channels, and we really don't want to look like we don't know what the rules are there.

2) We've had some solar flare activity over the past few days, which can create a total blackout on the lower bands for several hours on the daylight side of the planet. I keep this page open on a tab on my browser and check it often:

Currently, over the past day and a half, I see four M-class flares and a handful of C-class flares.? If these occur during the day, they will cause excessive attenuation on the low HF bands for an hour or so.? An X-class flare can cause a complete blackout for several hours.

3) Also, be sure that you have not moved your USB cable to your IC-7300 to a different port on your PC or USB hub, as that will cause Windows to assign a different COM port(s) and assume that the audio codec from the IC-7300 is now your default PC microphone and speakers.

Do a Windows-R and then type mmsys.cpl in the Open: prompt and click OK.? This will launch the legacy Windows sound control panel, and then you can ensure that your IC-7300 audio codec is NOT marked with any green checkmarks.? Green checkmarks should only be on your PC Mic and Speakers, to make them the default Windows sound source and sink.

Check the Playback and Recording tabs on the Windows sound control panel to get everything set up.? On the Communications tab, check 'Do nothing' to prevent Windows from tinkering with your volume controls if it 'detects communications activity'.

It's helpful to go into the properties for your IC-7300 audio codec on the Windows sound control panel, and rename the input/output to an easily recognized name that will be easy to distinguish when selecting the audio codec in various digital programs, like WSJT-X and VARA HF.? Remember that those names will only show up if your IC-7300 is connected to your PC and the radio must be turned on.? WSJT-X in particular, has a bad habit of returning your audio selection to the Windows default in its preference panel, if it doesn't find your IC-7300 audio codec when you open the WSJT-X preferences panel with the radio off or disconnected.

Also, make sure that for your IC-7300 audio codec device properties in the Windows sound control panel that all compression and other sound enhancements are turned off, as they will interfere with your digital encoding/decoding.? Likewise, use the USB/digital mode on your radio, instead of just plain USB.? That should turn off any compression or Tx/Rx equalization that you may have set up for SSB audio modes on your radio.

Hope that helps.

开云体育