tag:blogger.com,1999:blog-4901205574058136834.post7385482464115381337..comments2024-03-26T20:17:30.126-07:00Comments on Every Blade of Grass: NOAA Weather Satellites and RTL-SDR Dongles, Part IIdrjimhttp://www.blogger.com/profile/05647484115197408897noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-4901205574058136834.post-19006555065422871982013-12-03T18:15:29.372-08:002013-12-03T18:15:29.372-08:00It's "WBFM" in that it's wider (...It's "WBFM" in that it's wider (about 40kHz) than voice is, but not nearly so "WB" as FM Stereo (230kHz!!) is.<br /><br />WxtoImg was throwing some error messages about the bandwidth being too narrow, so that's when I spent the time and figured out how to increase the BW in HDSDR. SDR# has an "APT" setting if you know where to look, and I found it, and I'm getting some decoding, but not of acceptable quality.<br /><br />The preamp I'm using is exceptionally good (.8dB NF), BUT it has some filtering in it designed for the 2 Meter Amateur band. Using it makes the signal appear stronger on the spectrum displays of both HDSDR and SDR# compared to turning it off, but I'm going to try a pass with it turned off just to see if it matters.<br /><br />I also have yet to try the FUNCube dongle to record a pass with using the new antenna. Seeing as the FCD has built-in bandwidth limitations (only about 80kHz usable), I'm wondering if that might help. One thing I did manage to do was change the sample rate so that a smaller slice of spectrum is received by the RTL dongle, and that made it easier to correct the Doppler Shift.<br /><br />I might just make a simple turnstyle antenna (crossed dipoles fed 90* out of phase to get RHCP) for 137MHz, and gin up a simple preamp/filter for 137MHz, and use that for a dedicated WX_Sat antenna system. The only reason I started messing around with using the 2 Meter Eggbeater is that the VSWR curves looked excellent at that frequency, and M2 even said it was an acceptable antenna for that use.<br /><br />Still a Work-In-Progress I guess!drjimhttps://www.blogger.com/profile/05647484115197408897noreply@blogger.comtag:blogger.com,1999:blog-4901205574058136834.post-12177031170142867912013-12-03T11:29:09.395-08:002013-12-03T11:29:09.395-08:00Well, I don't know anything about the modulati...Well, I don't know anything about the modulation, but I think I recall it being WBFM. Any chance it's something silly, something like the mark/space being reversed? SiGraybeardhttps://www.blogger.com/profile/00280583031339062059noreply@blogger.comtag:blogger.com,1999:blog-4901205574058136834.post-66854315548713443352013-12-02T06:36:06.882-08:002013-12-02T06:36:06.882-08:00At least you've got something to keep you busy...At least you've got something to keep you busy! ;-)Old NFOhttps://www.blogger.com/profile/16404197287935017147noreply@blogger.com