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longview posted:almost a 100% chance that running a 1500W 2.4GHz link and taking out wifi for the surrounding county will get you into some kind of trouble, european limit is 300W on VHF and up but anything above ~1W will take out wifi over a pretty large area This is my big thing. After the UPS debacle* I started viewing the FCC in a rather dim light, and am terrified that they're going to just razor shave down our bands one bit at a time if we don't say anything until they've destroyed all the ham bands for _very_ minor incremental advances in their own service *in the early 90s, UPS started crying and crying about how they needed a dedicated radio band for their trucks and how about 220-222 MHz out of the 220-225 MHz ham band, FCC said naw, UPS said BUT WE WANT IT and then FCC said okay and took it away from hams and then UPS said "aw jokes, jokes. Looks like 220-222 won't work out for us. We're good though - cellular data is here! Peace out" and the FCC never gave it back to hams.
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# ? Feb 24, 2014 20:33 |
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# ? May 13, 2024 11:21 |
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so what happens if hams just start using that band again? if ups isn't using it anymore, does anybody even care
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# ? Feb 24, 2014 20:35 |
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afaik they resold it at much lower prices to other private services, so if you interfere with them, they call FCC, white van visits, Notice of Apparent Liability, five-figure check made payable to FCC
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# ? Feb 24, 2014 20:38 |
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gently caress
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# ? Feb 24, 2014 20:39 |
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spankmeister posted: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 i'm too stupid to understand how this works. is his signal so powerful that whatever wires used in his earbuds act as antennas?
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# ? Feb 24, 2014 20:47 |
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Verdafolio posted:i'm too stupid to understand how this works. is his signal so powerful that whatever wires used in his earbuds act as antennas? in a word, yes SSB and AM transmissions transmit information by varying signal strength in tune with the signal, semiconductors and other metal-metal junctions can act as the rectifier diode in the AM receiver I talked about a while ago, the effect would be that you get a receiver out of audio circuits, digital circuits can be affected but usually not enough to cause noticeable interference since they're usually shielded against external RF and to prevent the signal wires from generating interference as well this was a huge problem with all 90s consumer audio equipment, and many cheap amplifiers today, when GSM phones are placed nearby the time division nature of the signal means it turns on and off the transmitter at a frequency you can hear when it's rectified in an inadvertent receiver manufacturers eventually sorted out the GSM signals by shielding and using opamps with built-in RFI shielding (opamps with EMI shielding are like magic compared to ones without), the reason they did it was of course because people were noticing the problem the only people who notice CB and Ham activity are people right near powerful transmitters, AM radio transmitters have the same problem but they can usually put the transmitter in a mountain somewhere and do a remote feed FM signals have a continuous signal strength so when this rectification happens it'll just cause some DC to appear, often a bit of 100/120Hz hum from the power supplies on top of it but it's not as big a problem TV transmitters might also cause problems, analog TV used a sort of SSB called VSB that varies with picture brightness and DVB-T transmitters use OFDM, a linear digital modulation form that can also cause this problem to prevent this problem, you can direct the transmitter to direct power elsewhere or otherwise lower power, or try to work out what wires are causing problems and put clip on RF chokes on the wires, coiling up the wire for a few turns can help against higher frequency noise too but usually if you're getting interference in there's either a very strong signal nearby exceeding the civilian EMC test spec(10V/m I think is the toughest civilian spec, mil-spec is about 200V/m of RF at different frequencies + often an EMP test) or the equipment designer or installer made a mistake longview fucked around with this message at 21:06 on Feb 24, 2014 |
# ? Feb 24, 2014 21:03 |
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longview posted:in a word, yes Yep. this is also why I personally do not 100% discount the "my filling made me hear radio signals" stories. I think it's possible to have a semiconducting junction inside a bad filling, which could pick up enough energy to fire audio nerves. it'd be a 1 out of 100 million thing, but i want to believe
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# ? Feb 24, 2014 21:07 |
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longview posted:almost a 100% chance that running a 1500W 2.4GHz link and taking out wifi for the surrounding county will get you into some kind of trouble, european limit is 300W on VHF and up but anything above ~1W will take out wifi over a pretty large area i guess im not good at this nomenclature thing. i was thinking of using ham freqs as like a P2P 'WAN' connection that u'd hook up to a wifi router on ur camping trip then VHF or w/e back to wherever u have an internet uplink also jonny how common are the white vans? like... have i likely seen one in the past 6 months and not known it? gov't plates or just whatever plates?
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# ? Feb 24, 2014 21:20 |
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goog says the white vans are limo tint green suburbans lol
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# ? Feb 24, 2014 21:29 |
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PuTTY riot posted:i guess im not good at this nomenclature thing. i was thinking of using ham freqs as like a P2P 'WAN' connection that u'd hook up to a wifi router on ur camping trip then VHF or w/e back to wherever u have an internet uplink It might or might not be permissible. If it a: violates any obscenity guidelines, or b: is of a commerical nature, it's verboten. If the traffic was encrypted at one time, it's fine as long as you pass it unencrypted over ham airwaves (TCP/IP and HTTP are both allowed and widely used on some packet networks). The white vans are rare, I think they have some on each coast and then chicago/dallas, and they travel onsite based on complaints. you won't find one in oxford unless the cops' radios or university PD is getting interfered with
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# ? Feb 24, 2014 21:30 |
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coffeetable posted:is amateur radio astronomy a thing Coming back to this - didnt forget about you. I don't really know! But last night I got so deep in the satellite books that I taught myself what Lagrangian points are and now I want to join AMSAT (the amateur radio satellite org) and hook them up with some 2.0 millionaires who want to get press. They need like 5 million bucks to launch Phase 3E (the next wave of high orbit satellite) and its been just loving sitting in project hell for literally ten years now. thing is huge, will require a big rocket and a boost up to a big orbit of course any 2.0 millionaire is going to not be altruistic at all so it won't work. sorry we're not going to put streaming ads or your companys name on it Anyways i'm going to see if anybody is doing amateur radioastronomy stuff. As long as you can get some sort of receiver set up for the proper frequencies theres no reason you cant point an old TVRO dish at the sky and see what you hear
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# ? Feb 24, 2014 22:10 |
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~~D-Star~~ What is D-Star? D-Star is a amateur radio standard for digital radio, it supports two modes, Digital Voice and Digital Data, DV is the only mode in any real use so I'll focus on that D-Star was developed by the Japanese Amateur Radio League with government funding from the late 90s and standardized in the early 2000s, it is to my knowledge the only wide spread digital voice mode designed specifically for amateur radio requirements. it is an open sores protocol that is fairly well documented, it does use a proprietary voice codec that is the root of a lot of criticism Additionally the only manufacturer to deliver working out of the box radios is Icom, they were part of the design process and worked out of lot of the bugs in the original system. DD mode doesn't have a voice component (I think) and allows a 128 kbit data link, it's only supported in the 23cm band and only one radio, the Icom ID-1 supports it. this radio has an ethernet port and it's possible to use it to run normal TCP/IP traffic over this channel At a technical level DV mode uses a 6.25 kHz channel as opposed to a 25 kHz FM Voice channel, and the more modern and lower quality 12.5 kHz narrow FM voice channel that is starting to be mandated at the core it has a 4800 baud digital channel, of this a proprietary AMBE2020 codec is used to make a 2.4 kbit/s voice bitstream, 1.2 kbit/s is used for forward error correction and the other 1200 bauds are mostly left up to the implementer in practice the 1200 baud channel supports digital data transfer at a glacial pace (D-RATS) and is also used to transfer a text message included with the callsign, and Icom supports D-PRS for position reporting over this channel too the air interface is a GMSK signal encapsulated in an FM carrier, there is no time division or other multiplexing technique so only one person can talk per channel, this is an advantage because it means a lot of radios can technically support it as long as they have a 9600 baud data port or can be modified to have one, most radios with pure FM transmitters (not phase modulated) can be modified for D-Star support D-Star originally only operated in the 23cm, 70cm and 2m bands, but the IC-7100 supports running D-Star on all HF band plus 6m, I think most use is restricted to 10m and higher since the bandwidth needed is big compared to SSB and it might not be the best protocol for HF propagation IMO What can I do with it? D-Star DV mode supports both slow data transfer (position reporting for example) and voice, the neat thing about D-Star is it's digital so it can be stuffed into the internet pretty easily this allows multiple repeaters to be linked up to the same chat room, typically called reflectors or rooms, when anyone at any linked repeater starts talking, all the other repeaters transmit this signal the most popular set of rooms right now is the DCS system, which has rooms for every country with more than a few users, each country usually has a set of rooms for regions, testing, emcomm and so on DCS013 (Norway) and probably others now have Echolink (a similar system for linking FM repeaters) gateway rooms too, I tested this yesterday and it worked pretty well another neat feature is basically SELCAL, this system allows you to automatically connect your repeater to another repeater using the callsign of the person you want to reach (technically the last repeater this person was registered at, this happens whenever they key the transmitter) unfortunately it doesn't work that well in the original implementation because call-sign routing (that's what it's called) automatically disconnects anyone else using the target repeater and it requires that the answering party hit a button to reverse-route otherwise it won't be a two way link fortunately the germans who built the DCS system also built what's called the CCS system, this implements call sign routing by handling the linking in a different way where the target repeater is still connected to the room it was in, AND the calling repeater, allowing the caller to listen to active QSOs before making a call so basically you can chat all over the world or locally, using the internet Some myths D-Star is old - it is, but it's also the only standard with more than a handful of users, but then again most standards are old by the time they're in widespread use D-Star is Icom only - it isn't, the AMBE2020 codec is proprietary but is also widely available, Icom is the only manufacturer to provide a set of radios and complete repeater stacks to run D-Star but several projects offer Icom-free D-Star repeaters and radios if you're willing to DIY a bit Yaesu and Kenwood are playing a political game, all these manufacturers were able to make interoperable NEXEDGE/IDAS radios using very similar tech for example I can't decode D-Star on my Baofeng/IC-02AT, it's clearly encrypted and illegal Nope, the codec is available at a low cost and volume to anyone willing to buy the AMBE2020 chip, the rest of the standard is open source Other modes are more efficient - not really, Yaesu being Yaesu has a competing standard but I've literally never heard of anyone using it for anything except testing it once, this mode supports 9600 kbit but it uses twice the bandwidth so not really a big win, it does support dedicated data links at 9600 kbit so it's much faster than DV at data transfer DMR and MOTOTRBO is starting to gain traction, oddballs in the UK are starting to use TETRA radios these standards have some very nice features, like DMR using a 12.5 kHz channel with TDMA to run two voice channels at the same time, typically channel 1 is international and channel 2 is local chat for example. the disadvantage is the radios for this mode are not designed for amateur radio use, they often aren't keypad programmable and the programming software is usually expensive as hell if you can get it (vertex standard/yaesu being the worst at this) additionally repeaters are linked to whatever the sysop set it to whereas D-Star lets all valid users link the repeater to where they want it as an aside, if DMR was designed for amateur radio it would use the TDMA system on the repeater side to eliminate the need for duplex filters and splits, but they didn't because pro users don't care about buying a duplex filters, TETRA apparently supports using mobile radios as repeaters for HTs though D-Star has bad voice quality - well, ok maybe, it's good for being a 2400 baud link ok? people sometimes sound like they have a cold, and when signals are choppy the vocoder output turns into beep and bloops, but over all it's not bad Internet linking isn't real DXing, when the internet goes down the whole system goes down! I won't comment on DXing or not, depends on the definition you use. When the internet goes down so does systems like Echolink, but then it's not like the FM repeater will reach any farther than the D-Star one anyway D-Star makes it easy to link up repeaters and hotspots across bands and distances when the internet does work, which is a big advantage for many emcomm operations. using hotspot nodes it is also possible to run cross-band repeaters on HF bands (think 40 meters NVIS) without generation loss like you'd get on a long chain of analog cross bands So what's a hotspot, how do I make a repeater? To make a repeater you buy the ID-RP2C repeater controller, then you choose what bands you want, most users want a 70cm module, the ID-RP4000V, and many want the ID-RP2000V 2m module and at only the price of a cheap car it's a real bargain, don't forget duplex filters! If Icom won't give you the repeater stack for free then you're not going to buy it, fortunately the germans really love D-Star and have made a repeater controller, the DV-RPTR. This is a GMSK modem, a powerful DSP and some interface hardware for keying radios, USB and Ethernet. The DV-RPTRv2 is usually used as a node adapter, or a modem. To make a working hotspot (simplex internet gateway), you need a radio with a 9600 baud packet radio port and you have to make your own interface cable, after that's done it's plug and play. If you're like most people you'll then get a raspberry pi running some obscure linux distro and some software called irddbgateway and dvrpt-controller, if you're a shaggarian übermensch like me you get a windows server 2012r2 vm running in hyper-v and run it there instead. To make a repeater you need two radios or a suitable repeater and duplex filters, but the same DV-RPTR can be used provided it has internet. When we set up our local 70cm repeater we used two FT-7900s and then a second DV-RPTR configured as a hotspot to remotely feed the repeater the same way echolink is usually connected. The DV-RPTR can also be bought with an AMBE codec and a display, the same setup then works as a normal D-Star radio only more clunky and about as expensive, but it does support directly connecting to the internet at the same time. So to end this, here is what D-Star isn't: Professional grade modern digital radio - it isn't, pro users have other requirements and would find D-Star massively confusing to operate, TETRA, DMR and P25 are far better options for pro users but are too limited for amateur radio TDMA FDMA and CDMA packet oriented (except DD) high bandwidth true diversity roaming - it's none of those things except one radio supports diversity receive, it's an improved analog FM, not 4G LTE Encrypted - there is no support for encryption except for what you put in the data-channel
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# ? Feb 24, 2014 22:14 |
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Jonny 290 posted:Coming back to this - didnt forget about you. if you can somehow insert the words 'augmented reality' in there i could prob help u out on that funding
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# ? Feb 24, 2014 22:14 |
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my .01% cousin or w/e that's running for texas house has a older bro that constantly posts venturebeat articles about augmented reality and google glass and owners manuals for ur car that are on ur phone. i dont think that would work tho so sorry for the derail
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# ? Feb 24, 2014 22:21 |
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Jonny 290 posted:Coming back to this - didnt forget about you. convince them that you're going to put *famous dead science guy*'s ashes into a non decaying orbit
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# ? Feb 24, 2014 22:21 |
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Payloads: -1 Molniya orbit satellite with transponders on five different band pairs, attitude thrusters, magnetorquers, deployable solar panels and redundant backup control systems -10cc semen, preserved, from Bill Nye
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# ? Feb 24, 2014 22:41 |
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why do i always learn about science guys dying on this forum harold ramis
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# ? Feb 24, 2014 22:55 |
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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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consistently acing first half of tech exam. to do: memorize approximate band --> freqs memorize all formulas learn schematics practice a lil dB math (haven't done calculus since B Cal 2 my soph year of college, ugh) idk if im gonna have time to get comfortable w/ general much less extra before monday. we will see i guess, no harm in taking it either way i suppose.
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# ? Feb 25, 2014 00:09 |
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syscall girl posted:science guys...harold ramis uh, bill?
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# ? Feb 25, 2014 00:11 |
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PuTTY riot posted:consistently acing first half of tech exam. if you have any Q's ask them here and if i miss it/dont answer, PM me im excited for you! srs
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# ? Feb 25, 2014 00:19 |
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thanks, ur like my e-elmer
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# ? Feb 25, 2014 00:24 |
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PuTTY riot posted:thanks, ur like my e-elmer trufacts: I was my Dad's Elmer. i'm a KC4 call and he jumped in the game about 4 years later, got a KD4. TO AUDIENCE: "Elmer" is the hobby term for an experienced ham mentor that gets you into the hobby and shows you the ropes. No crazy grey cats here sorry
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# ? Feb 25, 2014 00:25 |
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I've got a uniden BCD996XT and it's fun to listen to the police but it's so loving complicated also a windstorm blew my shortwave antenna down so I haven't DXed in forever. you can get some wacky poo poo on shortwave
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# ? Feb 25, 2014 00:51 |
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are QSL cards dead or are they still A Thing? they seem kinda cool
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# ? Feb 25, 2014 00:54 |
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PuTTY riot posted:are QSL cards dead or are they still A Thing? they seem kinda cool very much still a thing. internet call databases mean its way easier to send cards out, and people are more likely to send a card if they get a card i'll see if i can dig up some that ive gotten
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# ? Feb 25, 2014 00:57 |
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heres what seems to be a pretty good study website, i like that it tracks progress on each subelement so u know what to work on: https://hamstudy.org gonna finish up technician tmw and then rest of the week is gonna be general. i think extra is way too lofty @ this point maybe ill get it later.
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# ? Feb 25, 2014 09:13 |
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Jonny 290 posted:in this thread we discuss everything involving those wonderful ways in which humanity hurls epithets at each other via the invisible magic of RADIO WAVES lotta words here
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# ? Feb 25, 2014 09:23 |
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keep honking, i'm reloading i can type for this poo poo until the end of time. work week brings less radio fun, i am ordering a $20 SDR on thursday though
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# ? Feb 25, 2014 15:11 |
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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
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# ? Feb 25, 2014 15:22 |
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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 no (unless youre the nsa)
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# ? Feb 25, 2014 15:27 |
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my sister works for nsa do you think she could get me some gear
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# ? Feb 25, 2014 15:30 |
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also gsm is dumpster garbage trash and cdma is much better
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# ? Feb 25, 2014 15:30 |
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if only cdma was on any networks that weren't dumpster garbage trash
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# ? Feb 25, 2014 15:30 |
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I possess no fewer than three radio receivers that can receive the AMPS cellular band too bad analog's dead used to listen to people's calls down in hot springs in like 2000. BORING. SO loving BORING. "what do you want for dinner?" "i dunno. what are you feeling like" forever
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# ? Feb 25, 2014 15:32 |
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Kevin Mitnick P.E. posted:if only cdma was on any networks that weren't dumpster garbage trash 3g but now everybody uses 4g which uses ofdma which is like cdma but better
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# ? Feb 25, 2014 15:33 |
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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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hey jonny. if i use tomato on my routers @ home and want to bridge them and set them 2 a non-us zone that allows like channel 14 on 2.4ghz how much trouble will that get me in and is it far enough away from normal wifi to get away from all the other aps on 2.4ghz?
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# ? Feb 25, 2014 16:28 |
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Shaggar posted:hey jonny. if i use tomato on my routers @ home and want to bridge them and set them 2 a non-us zone that allows like channel 14 on 2.4ghz how much trouble will that get me in and is it far enough away from normal wifi to get away from all the other aps on 2.4ghz? set them to japan, you should get channel 14, nobody cares, go fuckin hog wild 14 is far enough from 11 that it should be pretty rock solid
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# ? Feb 25, 2014 16:29 |
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# ? May 13, 2024 11:21 |
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Bloody posted:also gsm is dumpster garbage trash and cdma is much better wrongo. compatibility > everything else.
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# ? Feb 25, 2014 16:29 |