Another "new" project popped up yesterday on the Iowa during our monthly Radio Guys meeting. Our guy who's rebuilding the CEC (Combat Engaement Center for the civvies) brought up the fact that eventually the Meterology Office on the Bridge Deck will be included on the tour route, and wouldn't it be nice to have a working weather fax on display.
This came up because I was explaining the PC, interface, and software I installed for the Amateur Radio Group to use, and showing how it's used to decode "digital" transmissions.
The most popular digital mode on the Ham bands is called PSK31, and is a narrow-band method of sending text, so you can have a keyboard-to-keyboard chat with another Ham.
The software I like to use is call "FLDIGI", and runs on Linux, Mac, and Windows. The nice thing about it is that it comes with software modems to decode literally DOZENS of digital transmissions.
There's nothing showing in the screenshot below as I don't have a radio hooked up to my Linux box right now, but I've mentioned FLDIGI before in other posts.
Here's a Windoze screenshot of FLDIGI receiving a weather report. The Signal-to-Noise ratio of this frequency is worse than the weather map, which explains the "snowy" image, and lack of correct side-to-side sync. This can be corrected in the program after the broadcast is recorded.
For a webapge giving the "Sights-and-Sounds" of the digital modes, head on over here. There are many other digital modes used, and this is just a small sample of them.
SO.....after the meeting yesterday, I looked up some wefax frequencies, and tuned in the Pt. Reyes Station Coast Guard broadcast, and tried to decode it. I'm not sure what was wrong, but we weren't able to decode an image. Since I've never tried that mode before, I suspect it might be operator error, and left it at that.
This morning I fired up my Windoze PC and my Flex 5000, and tuned in the same station. To my surprise, and using the defaults in the program, I was able to receive the image shown below.
This has me scratching my head, so I'll have to spend some time on the Iowa by meyself to see what's not configured correctly.