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Joining SDR chat, I took my Technician test earlier this week and am now to be globally known as KN1UIW (I'm just happy I got a whiskey in my assigned callsign). I've got multiple RTL-SDRs and I've camped out on 146.520MHz and never heard a thing. I've also tried to tune into some repeaters in my area and never picked anything up either. Is there a better frequency in the cheapie SDR's range I should sit on to hear people? My antenna is just a 510mm piece of solid core 20AWG jammed into a Type N connector with another 510mm piece of that same wire crushed under a nut on the barrel of that connector so I don't have a ton of range either.
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# ¿ May 9, 2019 22:57 |
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# ¿ Mar 28, 2024 20:25 |
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Partycat posted:The thing with analog FM call is you need to be sitting on it to hear anything and people don’t chat there normally. More than once I’ve driven from NY through Chicago on the 90, or cutting through Canada, and I haven’t heard jack poo poo. This is the first time I've started in earnest to try to pick up VHF since I've usually only worked with decoding digital stuff in the 915MHz ISM band and building my own transmitters for talking on that. Thanks for the info, I'll keep poking around and set up a scanner myself to hop around the frequencies and hopefully catch someone making a call. It's more of just a personal goal to be able to pull a conversation from the air like magic more than a desire to chat with people.
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# ¿ May 11, 2019 12:34 |
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Hey guys am I doing Amateur Radio right? I was able to receive my first transmission on HF today! I have my technician's license but still haven't bought a transmitter since I am still exploring what's out there and I don't have much money so I can't afford to buy equipment I might not use. That's a USB battery pack -> Raspberry Pi 3A+ -> rtl-sdr.com v3 -> sma to type-F -> piece of old cable tv cable -> salvaged power supply choke with wire salvaged from something else (a terrible 9:1 unun) -> screwed to a wooden garden stake, clamped to a ladder -> hookup wire (29ft) -> broom attached to the fence with clamps. The Pi runs rtl_tcp doing direct sampling, to which I connect over wifi with SDR#. I had tried it with just the wire stuck into the SMA jack on the rtlsdr but got nothing so this was going to be my last effort before I gave up. I'm super pumped when I was able to pick up CW on 40m, and then people started talking on 40m. I heard it all. Almost could understand the majority of it too. I'm super pumped I was able to hear something for a change. I pick up a lot of DMR on 70cm, some regular nets on 2m, but never really hear people chattin' it up so I've been kinda lukewarm on jumping in, especially considering that I live in a pretty restrictive HOA. "An antenna?! What are we, a bunch of poor people?!" It really gets exciting when there's stuff to hear and soon people will be hearing about how *my* weather is.
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# ¿ Sep 13, 2019 23:07 |
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Progressive JPEG posted:That rules and I'm kinda jealous because all my radio equipment is still in boxes from a move. You're effectively getting 100% more done with your ladder and RTL-SDR than I am with a couple grand of equipment and parts!
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# ¿ Sep 14, 2019 17:32 |
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Ah see now this is good advice. When I google for people talking about those Baofengs, there are tons of people using them and seem to be really keen on owning multiple of them. I hear about the good bits and not as much about the bad. I was considering waiting a bit and getting a mobile station instead and it sounds like that's what I should be doing. I've got a couple scrounged 12V power supplies that should be able to run one and my 2m/70cm antenna-in-a-pvc-pipe would probably be a better match for that instead of a HT. There's also a hamfest in the next county over in a couple weeks so I'll probably go see if someone's unloading something.
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# ¿ Sep 15, 2019 03:01 |
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Pimblor posted:Who needs to read hamsexy, just go to your local small town hamfest, better than the county fair. I got my toroid and upgraded my garbage random wire antenna with a proper 9:1 unun with a counterpoise and everything. I'm really confused after hanging it up this morning. I'm on 20m and hearing a guy in Kansas talking to guys in Quebec and Alabama and Connecticut then someone in Florida. I can only hear him but I can hear him STRONG. I can also hear a guy in Georgia talking to someone in Florida. According to HAM Universe I should only be hearing people from 20-75 miles or "up to a few hundred miles". Are there HF repeaters or something that I am unaware of, or is it possible to hear people a thousand miles away on 20m?
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# ¿ Sep 26, 2019 15:26 |
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Pham Nuwen posted:What it's saying is that 20m is good for long range contacts during the day, and that if you end up talking to someone who's only a few hundred miles away it's probably because your signal went around the other side of the world. The bit about ground wave signals means you may also pick up people who are within line-of-sight, but that's not the primary method by which contacts are made. Thanks for setting me straight, I just thought there was no possible way a RTLSDR operating in a direct sample mode attached to a piece of drat wire could pick up anything from more than a few dozen miles away. CapnBry fucked around with this message at 16:34 on Sep 26, 2019 |
# ¿ Sep 26, 2019 16:31 |
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Jonny 290 posted:20 meters is just kind of notorious for that. There's a big "no coverage" donut hole for a few hundred miles around you, after that the signals boom in. I'm like the guy that d0s expects to find on amateur radio. Building stuff from the 3D printer and scrap bits and whatever wire I can scrape together and being just amazed at the possibilities and how ingenious people are to create antennas. Note kickin' rad 3D printed wingnuts too, although I am a bit upset I didn't do them in different colors but not enough to actually change the spool just to print 0.1g of plastic.
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# ¿ Sep 27, 2019 03:15 |
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Oh I am happy to have contributed something to this thread then: increased desire to buy more gear. Whenever I see 3D printers, I mostly see people posting photos of some random useless plastic knick-knack or lovely vase / pencil holder. My printer prints only functional equipment, with project enclosures being the top use. The only problem is that I spend way longer than I should iterating on the design after it is functional. Last Saturday I said "Let me just throw this together" and 3 hours later the best and most overdesigned 8mm mini T-handle socket rolled off the printer. That's right, three hours to make a cylinder with a toggle on top... but there's not another one on the planet that fits my hand exactly as well as this one. Speaking of which I realized last night that there's a huge flaw in my unun enclosure design in that the wire wrapper bits block access to the little handle on top I use to hang it from a hook on my patio. If I rotate them 90 degrees they block the wingnuts rotation. If I turn them into an X then the wires will wrap over each other and I wanted to keep them separate so I can only deploy the counterpoise when I feel like it. I might have to reimagine the whole thing into more of a kite spool shape now but then I'd need two spools and now this is spinning out of control.
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# ¿ Sep 27, 2019 13:20 |
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Jim Silly-Balls posted:What’s your favorite way of scanning the whole (RTL-SDR usable) spectrum for signals? The SDR# frequency scanner never seems to work for me, but maybe I’m doing it wrong? Yesterday morning I set up my longer (41ft) wire and was able to get tons of 40m traffic, as far away as California and New York (from Florida) and even a guy in Dallas who said he was only 150W, clear as a bell. Today my reception is garbage and even the signals I can get fade out entirely. I also picked up some people on 80m. I didn't end up buying anything at the hamfest yesterday-- I just didn't know enough about what I was looking. Some people were nice though and willing to just chat about what they've got and why they're getting rid of whatever they had to sell, so it was an enjoyable morning. My favorite thing I heard yesterday was some guy on the 15m band who was going on about how in the 50s the US and the communists had a plan for world peace and were working toward merging and they just needed a war to get everyone on the side of peace, so they planned to sink the Lusitania together and put ads in the newspaper to tell people to not go on it and oh man my head was just spinning.
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# ¿ Sep 29, 2019 18:02 |
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Jim Silly-Balls posted:Where do you guys find is the best frequency to hear actual voice? Or maybe I should be asking where is the best place to go to find out for your location? 99% of the spectrum is tones and digital data these days it seems Then I jumped on my club's weekly net and hooray people! That's when I also found that there's a buncha nets going on on Tuesday night, including one that takes them like 20 minutes just to check everyone in. Listening to the nets from the repeater and switching over to the repeater inbound frequency to hear the station's actual transmission gave me a lot of experience in messing with my setup and getting the antenna in the right place to get good reception. So I guess my answer is to look for clubs in your area, see if they have a website, then check out their net. It is a good time to find other people too-- when a lot of people are idling around waiting for their nets. Other than that, I have a hard time finding people talking on 2m/70cm but other than net o'clock the highest traffic I see is during morning commutes and Saturday morning. 70cm being more active. I've never heard anyone on 146.520 and I sat on that frequency for days after my Technician's class told me that's where conversations start. The other option if you have transmit ability is to just call CQ and see if anyone answers. HF is full of life if you can get down there. There's always a few people talking on 40m although my reception is still pretty hit or miss. I'm not sure how people find other people to talk to without an SDR or some sort of waterfall though.
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# ¿ Oct 2, 2019 02:23 |
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Wardriving! I used to do that with my laptop and a bluetooth GPS that was wired into the 12V supply in the back of my old 4Runner that I think cost like $70 at the time. I haven't done that in a long long time and I kinda want to now that we have Raspberry Pis and 2.4GHz yagi that cost like $8. I already have a USB GPS and a wifi dongle with an RP-SMA jack... great now you've just put another shovelful of project in my project pile.
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# ¿ Oct 31, 2019 18:20 |
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Actually the hardware designer is just being contracted to make a new version that is almost completely redesigned from scratch with the commonality being that it can run the same firmware and is about the same size. They're giving away the schematics and gerbers for free as soon as it is done. The original creator of the NanoVNA simply asked for a name change to differentiate it from his design, which seems fair enough, but they're not in charge of naming whatever product comes out because they're just designing the hardware. Seems fair enough. For those that don't know, the NanoVNA is a $40 VNA with a (lovely) touchscreen and lipo battery that does S11 and S21 measurements from 50KHz - 300MHz and can measure up to 900MHz with reduced accuracy. It is pretty OK tool, but pretty amazing for its price point. You can't even get a low end VNA for 10x that price. The "V2" is redesigned to go up to 3GHz with increased accuracy across the board, targeting the same price, so I'd say hardly lol-worthy. Sure going to beat my setup with an RTLSDR, broadband noise source, RF bridge, and rtl_power doing sweeps to just get reflected power for the same price.
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# ¿ Jan 8, 2020 23:24 |
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longview posted:Below the antenna is a stack of circuit boards:
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# ¿ Feb 22, 2020 20:58 |
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rdb posted:Thanks. I ordered one from nooelec directly. Amazon went from 1 week delivery to over a month overnight despite the item being in stock. No luck getting a raspberry pi anytime soon either. I am going to go ahead and just put linux on a spare external ssd for my mac. Lets just hope it gets here before whatever is about to happen does happen.
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# ¿ Mar 25, 2020 13:00 |
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Terminal posted:Also found out very quickly how insular and toxic the local GMRS & 2M repeaters are. I've got a dumb dumb question. I'm trying to throw together a quick 20m spiral loop antenna and I have never used a variable capacitor before. As you can see here I turned my L-C resonating bit into just a wire by soldering the loop to the solder lugs on both sides. Soooo where does one solder the other wire? To the clippy wire bit in the center? To the case somewhere? Sorry about the lovely lighting it was impossible to get enough light on it.
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# ¿ Apr 20, 2020 21:27 |
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If I have a Random Wire Antenna with a 9:1 unun feeding it, do I need to design an antenna tuner for matching the 50ohm to 450ohm impedance of the antenna or is it supposed to be virtually a 50ohm load already? I'm looking to pick up another variable capacitor to play with matching and I'm trying to determine how big it needs to be at max. Does the imaginary part of the impedance dominate the calculation when the unun is already trying to match the feed impedance? All of this is really low stakes just messing around experimenting and learning for fun on receive-only or lower power TX (10W max).
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# ¿ May 3, 2020 14:57 |
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Jonny 290 posted:It's supposed to be 50 ohms on the coax side of the unun, yeah. CapnBry fucked around with this message at 20:08 on May 3, 2020 |
# ¿ May 3, 2020 19:55 |
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Jonny 290 posted:I'll mail you one for the cost of shipping if you like, I just gotta figure out how to do curbside UPS/USPS pickup. I was wondering if the antenna you took a picture of with your (original) DJI Mini was your antenna or your neighbor's, but now I guess we've answered that question too.
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# ¿ May 3, 2020 20:16 |
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Jonny 290 posted:The big tall one with the cross pieces and all the wires is a full size 40 meter 'folded monopole'. It's by far the best antenna I've ever built, the thing is an absolute rock star on 40 meters. 2:1 SWR curve is between 6900 and 7350 kHz. So am I looking at this diagram correctly that in like the 5-wire, all 5 wires are active elements? How long (wavelength-wise) is each section? It is too big to fit in the area I have but I'd be interested to know more about it.
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# ¿ May 4, 2020 21:35 |
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Pardot posted:Not sure if this is the right thread but I just got my first rtl-sdr thing. It works, and I was able to tune into some radio stations which was kind of neat. I first wanted to read my power meter and https://github.com/bemasher/rtlamr all running, maybe, but it's not seeing any packets at all :/ Has anyone tried that before and know of any common problem spots?
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# ¿ May 16, 2020 14:22 |
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Nitrousoxide posted:I see some online study aids and courses. Any recommended ones? I got one of them-there NanoVNA V2 deals (back in April but it just came Saturday) and was able to tune my random wire antenna like a "Pro" instead of just listening for louder static. And 1.18 SWR and 49.4ohms impedance? C'maaaahhhn! Even more of a miracle because it is this pile of junk on a patio. Look, Ma, no inductance needed on 20m!
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# ¿ Jun 8, 2020 20:45 |
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I've been messing with my NanoVNA and I was really disappointed with some of the numbers I was seeing all of a sudden on 20m, then I moved another piece of coax out of the way and everything got much better. I've got two antennas on my roof, a 41-ft random wire with a 9:1 unun for HF, and a VHF/UHF antenna. The antennas are at least 10ft apart from each other. Each is connected with a separate length of RG-8X with PL-259 connectors on each end and I connect the one I want to use to the RTL-SDR. I notice (now that I can see it) that moving the unconnected VHF/UHF antenna's wire around greatly affects the SWR on the HF. The coax cables run somewhat close together for half their length. Am I supposed to ground out the unused antenna somehow to prevent it from being a passive element in the other? The SWR jumps from about 1.30 to over 2.5 just moving the disconnected antenna's coax end near the HF coax.
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# ¿ Jun 9, 2020 14:30 |
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manero posted:Try adding a counterpoise wire to the ground on the 9:1 unun, they can be kind of touchy with respect to SWR and feedline length, and chances are the antenna is looking for something to couple to the other "half" of the antenna.
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# ¿ Jun 9, 2020 15:37 |
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Can someone tell me if what I've got here is actually present or is some sort of harmonic artifact that comes from using a cheap SDR radio? It is some Spanish-language shortwave radio stations that come in incredibly well here in Tampa, but scrolling around I hear the same broadcast at a lot of places across many bands, and sometimes coming in right in the middle of my 20m (which is the same broadcast as what is just above 40m). I'm contemplating buying a more expensive SDR like an RSP1A or maybe cheap out and get an MSI.SDR, but don't know if it will eliminate receiving this in a place where I don't think it actually is. Right now I am getting it on 7.33500MHz, 7.365000MHz, 14.069800MHz, 14.100000MHz, 14.13000MHz, all the exact same stream. CapnBry fucked around with this message at 14:12 on Aug 10, 2020 |
# ¿ Aug 10, 2020 14:09 |
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poeticoddity posted:https://m.short-wave.info/index.php I'm trying to go the other way though, NOT receive these signals. I don't think there should be a shortwave broadcast on 14.100MHz but I am getting one there. I'm trying to determine if that's a function of SDR in general, or my antenna, or if it is just specific to the model of SDR I am using. I don't want to spend $100 or more on a new SDR if it turns out I'll get the same signal all up in my FT8 or blasting over regular phone.
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# ¿ Aug 10, 2020 15:22 |
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poeticoddity posted:Have you pulled up a receiver on websdr.org and compared the output there to yours? ickna posted:I would try reducing the sampling rate first to see if that gets rid of some of the images, and then try reducing the gain to see if any of the other ones go away. Uh oh looks like HRO has the RSP1A on sale right now for $99 whoops my money fell out, into their website.
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# ¿ Aug 11, 2020 03:16 |
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I cleaned up my antenna tuner layout, replacing the air coil with a toroid, and 3D printed a box to put it all in. Six dang hours of messing with the box to get all the holes in the right place and make a pair of matching knobs that fit. Along the way, the capacitor's 4:1 knob mechanism just stopped working entirely. I'm not sure how that works (there's 0 exposed parts which reveal its clockwork) but I'm sure as heck not going to take it back out to fail to figure out how to fix it. I just clamped the knob onto the larger shaft and I find tuning with that easier anyway. For reference, the setup that's been sitting on the porch for a month: And my RSP1A comes today, yussssss.
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# ¿ Aug 13, 2020 14:21 |
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Casual Encountess posted:project update? The RSP1A is great in that it has better sensitivity, and much finer gain control which means it isn't completely blown out by the shortwave stations on 40m. The echos of shortwave broadcast I was picking up in the middle of my 20m are also gone. Being able to grab large chunks of bandwdith at once is also great (up to 10MHz) which means I can get all of 2m or all of what I want to listen to in 70cm at once. What does suck is that using it with my setup of a Raspberry Pi A+ that sits outside all the time and SDR-Console on my windows PC in the nice air conditioning and big monitor / speakers doesn't really work. You can use SDRUno in ExtIO mode along with rsp_tcp to stream it, but the wifi doesn't have enough bandwidth to send 16-bit I/Q 2MHz. I'm not even sure it is working properly in that mode because SDRUno is not my favorite receiver app. I can use rsp_tcp with SDR-Console through the RTL-TCP input by chopping the 16-bit I/Q down to 8-bit (drop the top 2 and bottom 6 bits), but also the gain control is lost almost completely. I asked the SDR-Console developer about it and typed out all the specs for the "enhanced mode" API (which just adds a few more commands) and he said to just put a Windows PC outside all the time instead, which I won't be doing. That's pretty disappointing because I'm not getting full use out of the RSP1A, and because it isn't an open source program I can't add it myself. I may try to come up with a workaround by reverse engineering their V3 Server streaming protocol and wrapping the sdrplay API on the other side to emulate it. I don't know if I have that kind of energy for that, or will be able to figure out how they compress the I/Q samples. CapnBry fucked around with this message at 20:02 on Aug 21, 2020 |
# ¿ Aug 21, 2020 19:42 |
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Big Mackson posted:I use this https://github.com/F6FLT/SDRSharp_v17xx-Plugin-for-SDRPlay for my rsp1a. That said, it is nice that SDR# exposes their API so developers can write their own plugins to support things. I asked the SDR-Console dev for the DLL interface he uses for all his frontend plugins or any sort of information on the V3 Server protocol and he said no. It is a bit odd that it is free software but he really wants to lock it down.
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# ¿ Aug 23, 2020 18:26 |
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Big Mackson posted:we put a dll in your dll That' ExtIO dll is the one that worked in SDRUno, and thanks for pointing me to the URSP wrapper because SDR# I like a lot better than Uno. I just tried it and hooray you can get 16 bit samples into SDR#! Theoretically anyway, it definitely doubled the wifi bandwidth so I assume it doesn't get shrunk down going into SDR#, but I'll have to investigate. The RSPTCPServer is a bit wonky, I've already been hacking on it because it does all sorts of crazy stuff where it resets turning off AGC by mistake, and it is super puzzling why they went through all the trouble to make this EXTIO dll and then used this "gain index" thing instead of just exposing the actual separate gains used by the API. The Pi's network can't just barely keep up with 2MSPS at 16 bit as it is choppy and after some random amount of minutes I get a ton of kernel driver USB errors (from the sdrplay process) that requires me to reboot the Pi. Still not ideal but this could work slightly better than using rtl_tcp emulation so I'm happy to have more options, thanks!
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# ¿ Aug 24, 2020 17:16 |
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PhantomOfTheCopier posted:I had to take my radio out of my Jeep, sigh years ago now, because of frequent vandalism.
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# ¿ Oct 8, 2020 04:25 |
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the milk machine posted:i was fiddling around with a raspberry pi + sdr upstairs where i get better reception this summer; i think i was following along with this article: https://www.rtl-sdr.com/rtl-sdr-tutorial-setting-up-and-using-the-spyserver-remote-streaming-server-with-an-rtl-sdr/ My primary radio is an SDR plugged into a Raspberry Pi 3A+ with rtl_tcp that sits out on the back porch and I connect over wifi from SDR Console or SDR#. It works great other than me having to go outside to switch the antenna from HF (random wire with 9:1 unun) to VHF/UHF. I used to have an SDRplay RSP1A but in this setup it couldn't run 16-bit samples or grab a lot of bandwidth without choking the network connection, so I went back to just the RTL-SDR.com dongle which gives me 90% of the signal for 20% of the cost.
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# ¿ Dec 17, 2020 20:57 |
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Jonny 290 posted:Yeah sounds like you're talkin about slow scan tv on 20 meters.
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# ¿ Feb 2, 2021 19:27 |
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I'll second getting an SDR. I've had a handful of them over the years and my current budget favorite is the RTL-SDR.com V3 along with the antenna kit for $35 (which Amazon is out of stock on currently). This is a device to allow you to listen to people and things on virtually any frequency 500 kHz to 1.7 GHz, and more importantly, *see* the signal and ~2.4Mhz of adjacent bandwidth. This is a lot easier than scanning the entire band looking for people talking and you can just click on their line in the SDR software on your computer to start listening to them. The antenna set is nice because it lets you pick up stuff your Baofeng will (local conversations on 2m ~144MHz and 70cm ~440MHz). You can pick up aircraft positions with ADSB (1090MHz) and hear them talking with air traffic control if that's nearby too (108-137MHz) . You can see wireless devices like weather stations and smart meters talking computer-talk (not wifi devices) on 915MHz and 433MHz. You can uhhhh listen to FM radio too. There's all sorts of data in the air around you at all times and an SDR lets you see it all. You can also attach a giant wire to it and listen to 20m, 40m, 80m people as well as AM radio and shortwave. I've just got a 40ft length of 20AWG wire hung up in the tree outside and I hear people from over a thousand miles away and have picked up FT8 digital messages from as far away as Japan and Slovakia from central Florida. The only downside is you can't transmit, but it at least lets you see almost all of what is out there, and then you can get the equipment that lets you talk to who you want.
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# ¿ Feb 9, 2021 19:44 |
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Pennywise the Frown posted:Yeah that sounds pretty cool. Sucks that it's out of stock. Are there any other complete kits available out there? Like poeticoddity said, you can really start racking up the price if you add on an upconverter, but I don't think that's necessary. I had an RSP1A ($120 sdr) and it had cleaner reception but it didn't blow my socks off in comparison with the cheaper dongle. It also didn't work remotely with most software without degrading its performance down to almost the same level as the cheapie. I have a Raspberry Pi Model A+ that I put outside connected to my antennas when I want to listen from my desktop PC. That solves the "drilling a hole in my house" problem you mentioned earlier, by just streaming the data to SDRSharp or SDR Console applications on my desktop but hardware compatibility is very basic. When you start looking at high end SDRs, you might be in the $200 ballpark and while I'm sure their HF reception is top notch, I'd rather be looking at like an $999 ICOM IC-7300 which is a full 100W transceiver for HF.
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# ¿ Feb 10, 2021 15:08 |
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Pennywise the Frown posted:Does the antenna require drilling from inside of my house to outside? For HF a super convenient way to hook up a Random Wire Antenna is to get a little 9:1 unun like this that has the push terminal block connector and stick a piece of wire in the RF port in one of the following lengths (feet): 29 35.5 41 58 71 84 107 119 148 203 347 407 423. I use 41ft (or maybe 35.5?) tossed up into a tree and can pick up 20m from thousands of miles away. EDIT: You can also just stuff that wire into the center of the SMA jack but there's an impedance mismatch so you lose some signal and also it falls out easily. CapnBry fucked around with this message at 14:17 on Feb 18, 2021 |
# ¿ Feb 17, 2021 21:02 |
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horse_ebookmarklet posted:Got a 3d printer and I'm goin WILD making brackets and learning fusion 360.
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# ¿ Feb 19, 2021 18:21 |
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horse_ebookmarklet posted:NICE! I'm at a basic "make a profile and extrude/sweep" level right now. Bonus Achievement: Emboss the text of which antenna they are in the cap. I have VHF and HF wires that look identical so I just look at the cap instead of staring up at the sky trying to figure out which gray coax is which.
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# ¿ Feb 21, 2021 16:12 |
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# ¿ Mar 28, 2024 20:25 |
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Twerk from Home posted:Does it actually look like DMR will be the standard that will be most popular with hams in a few years? CapnBry fucked around with this message at 14:37 on Feb 23, 2021 |
# ¿ Feb 23, 2021 14:26 |