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thread owns an engineering student in holland made a web SDR gateway. SDR is hella cool b/c it basically allows you to listen to the whole spectrum at once (as much as your gear allows) then do the actual tuning and signal processing in software. this allows you to tune to any number of signals, simultaneously! so anyway this guy went and did that and made a web interface for it, so now you can go ahead and listen to a p big spectrum without needing any gear yourself.   http://websdr.ewi.utwente.nl:8901/ Oh and BTW they call the CB band 27MC here, MC being MegaCycles, the ye olde way of saying MegaHertz. you can imagine non-radio people getting 27mc and 27cm confused, which are two totally different bands. oh well.
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Feb 22, 2014 10:22
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longview posted:Fun fact: the local oscillator leakage can be severe enough in cheap radios that you can pick it up pretty far away, this is how the mythical TV-license van could detect a running TV by pointing a directional antenna at the aerial. this is how radar detector detectors work also
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Feb 22, 2014 12:59
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longview posted:that's a cool trick, I guess that's why some scanners have IF outputs, would save a little time it's all about having your tonge out at the correct angle when making adjustments
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Feb 22, 2014 23:33
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this overly enthusiastic australian dude visited an analog TV transmitter station recently, p interesting stuff: https://www.youtube.com/watch?v=mR_wJkxKSXU spankmeister fucked around with this message at 14:03 on Feb 23, 2014 |
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Feb 23, 2014 14:01
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aaaag all those different baofeng UV-5x versions are making me crazy i don't know which to get i'm just gonna get a random one i guess
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Feb 23, 2014 16:13
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Jonny 290 posted:just get the UV5RA if you are wanting to keep it cheaper, or get the GT3 if you want a better display and can spend a few more bucks i'm seeing these plus versions, they appear to have a bit more freq range: http://www.ebay.com/itm/Latest-Vers...=item43c14abb79 goes up to 520MHz i.s.o. 480MHz
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Feb 23, 2014 16:24
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Jonny 290 posted:Ah, go for one of those then (though that is a plus just b/c its an indication of a later firmware, not b/c there's anything between 480 and 520 at least in the US) thanks  after listening to that i'm reconsidering this purchase, however. e: caught your vid before you ninja edited
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Feb 23, 2014 16:49
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longview posted:EEVBlog is awesome, I prefer Mike's Electric Stuff videos when he posts them because they're always straight to the point, like today he posted a video about filling a tub with water and enameled wire to make a 800W dummy load yeah eevblog owns my only problem is that the guy Dave likes to ramble a bit, stretching a 10 minute video into 40 minutes. mikeselectricstuff owns too my only gripe with that one is that he needs to post more  i saw his vid on the dummy load earlier, the idea is brilliant
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Feb 23, 2014 22:35
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there's an shall we say "unlicensed amateur radio enthusiast" near my moms place and whenever he's transmitting i can hear it over my moms DECT phone.  e: thinking about reporting his rear end, i really could not give a poo poo about radio pirates if they have their poo poo together but this dude clearly doesn't have his poo poo together e2: i occasionally pick him up on my phone's earbuds whenever there is no music playing. also when i was still living there i picked him up on my (very very crappy) desktop mic spankmeister fucked around with this message at 16:03 on Feb 24, 2014 |
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Feb 24, 2014 15:58
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syscall girl posted:why do i always learn about science guys dying on this forum busting ghosts up in heaven. 
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Feb 24, 2014 22:57
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harold ramis
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Kevin Mitnick P.E. posted:is it possible to spy on people's cell phone calls. gsm, i figure cdma would be a total pita cause of the hashing thing and anyway only at&t has signal at my house in the sticks yes it is but it's easier with a phone with custom fw https://events.ccc.de/congress/2010/Fahrplan/attachments/1783_101228.27C3.GSM-Sniffing.Nohl_Munaut.pdf
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Feb 25, 2014 15:44
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CRIP EATIN BREAD posted:oh hey i found my fathers rig in my email: my_posting_rig.jpg drat you pops has a lot of cool stuff man, great condition too by the looks of it.
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Feb 26, 2014 00:04
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today i decoded some p2000 emergency services pager signals using my RTLSDR dongle and some software: p. neat
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Feb 26, 2014 19:51
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Jonny 290 posted:super hot, nice. feel free to kick deetz on the software down, I don't know poo poo about the rtlsdr stuff yet and am ordering a dongle tomorrow ok so i got a DVB-T dongle with the RTL2832U and a RT820 tuner chip. the 820 has a bit less range on the high end than the E4000 (1800 ish vs 2200 is) but the E4000 has a gap around 1.2Ghz or so? I'm not 100% on these numbers but ballpark. then i used SDR# (google for sdrsharp) which is a good program for working with these things. Looks like this:  (not my pic) e: the usb driver is finicky for this setup, the sdr-install on http://rtlsdr.org/softwarewindows takes care of that then you have to have a monitor mode thingy on your soundcard, on some cards it's called "stereo mix", or "what u hear" or something. this is so you get the audio output from SDR# into the decoder software the software to decode pager stuff is called PDW, it does all kinds of pager protocols. the screenshot i posted in my previous post is PDW. it's real finicky to set up right because you have to get the levels properly set up and there's like 5 different places you can set volume. i couldn't get anything to work right until i found this guide: http://www.rtl-sdr.com/rtl-sdr-tutorial-pocsag-pager-decoding/ the thing i was having trouble with was fixed with these settings: Tune to a pager POCSAG/Flex signal. Set the receive mode to NFM, filter bandwidth to 12500 Hz, filter order to 10, and turn squelch OFF, and filter audio OFF. Adjust the RF gain settings under the Configure menu until good reception is achieved. PDW does a whole bunch of protocols. the only thing to remember is that you can only do 2FSK this way, if you want 4FSK you need a "discriminator" or whatever. spankmeister fucked around with this message at 20:09 on Feb 26, 2014 |
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Feb 26, 2014 20:04
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transfatphobic posted:if i buy that cheap handset you mentioned in the cj thread what can i do with it? yeah i reckon you can if the pager freqs in the us are in the range of what the baofeng can receive. all you need then is a sound card and a whole lotta time to mess with a 100 gain sliders
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Feb 26, 2014 20:05
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Jonny 290 posted:Very informative! We should experiment with the other modulations because a discriminator tap is just a wider signal without any lowpass filtering, i'd imagine we can figure it out. the creator did opensource it a while ago so there are certainly possibilities.
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Feb 26, 2014 20:17
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there's some ERMES signals flying around here which is 4FSK so i can do some testing.
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Feb 26, 2014 20:19
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what else can you do with an rtlsdr? yeah, that's right. motherfucking airplane transponders bitch! next up is plotting them on a map but planeplotter is being annoying
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Feb 26, 2014 21:04
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the google map plugin isn't working but here's a live chart of overhead planes:  i think i'm at the limits of my setup SNR wise because i'm missing data but the standard whip antenna that comes with it has worked so far. it's inside on my desk and i've made no effort on placement or w/e.
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Feb 26, 2014 21:12
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PuTTY riot posted:ya the 99 was just a lemon or something, rear axle replaced under warranty, maybe the transmission too??? idk, the earlier ones and the newer ones were all better, just that year. anywhere between 2 weeks and 2 months really. 
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Feb 26, 2014 22:43
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Jonny 290 posted:holy cow that owns! 
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Feb 27, 2014 16:33
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i ordered a bunch of stuff today, most notably the baofeng UV-5RE+, with a nagoya RH-771, UT-106, USB cable and also a pigtail for my RTLSDR dongle so i can connect SMA antennas to it.
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Feb 27, 2014 21:33
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PuTTY riot posted:lemme know how you like that antenna. its fukken huge and would prob only be good for fukken around in the yard i probably ordered a fake because it was like $6 but oh well.
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Feb 27, 2014 21:44
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Jonny 290 posted:That's not a frequency limitation or anything by the way, it's just that air traffic still uses AM modulation and the little chinarigs only demodulate FM. what the baofengs do below 136 mhz? b/c air traffic control is like 118
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Feb 27, 2014 23:20
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Verdafolio posted:found a web based sdr: http://websdr.ewi.utwente.nl:8901/ if anyone wants to play around with the air around the netherlands i posted that poo poo on like page 2 son
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Mar 3, 2014 17:57
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PuTTY riot posted:im not having the best of luck w/ sdr# but im thinking its prob this poo poo antenna
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Mar 4, 2014 22:51
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yeah you need to crank the gain way up on those fuckers or the snr is poo poo
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Mar 5, 2014 00:33
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Jonny 290 posted:
lol why
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Mar 5, 2014 07:39
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welcome to the cheapo conputer radio club btw guys
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Mar 5, 2014 08:11
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that sounds cool as hell but can you get it on ebay for under $20? b/c i'd just get an RT2832 dongle and u can do p25 with a program called DSD
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Mar 5, 2014 13:08
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Dijkstra posted:See my latest post in the ham radio thread for a summary of the clusterfuck this is the ham radio thread 
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Mar 6, 2014 20:57
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Jonny 290 posted:You'd better believe that I am hitting them up as hard as I can to see if they need any engineering help, equipment or other resources. do iiiit
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Mar 7, 2014 17:12
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Jonny 290 posted:this is insane how many loving times do i need to post that before someone picks up on it goddam i posted it on like page 2 < >anyway thing owns also i used to live in the city where that receiver is located 
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Mar 8, 2014 21:37
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My RH-771 arrived today, i just don't have anything to hook it up to yet. in other news i tried to decode TETRA transmissions today but holy poo poo the software to do that is really bad.
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Mar 10, 2014 20:01
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idgi what are y'all talking avbout?
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Mar 10, 2014 22:11
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ohh i see 
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Mar 10, 2014 22:17
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Anyonw have good recs for a 1GHz antenna? I want to receive airplane transponders better.
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Mar 12, 2014 16:06
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Jonny's is in the "other" ham thread 
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Mar 12, 2014 21:09
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fuckin ebay. i received both my antennas but not my baofeng or my pigtail for my sdr. 
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Mar 13, 2014 10:38
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Jonny 290 posted:holy poo poo look at this guy's construction skills and attention to detail i love Manhattan style and this is really done right
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Mar 14, 2014 17:58
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