Hey /diy/, I spent a good chunk of last summer killing time on hamstudy, just for fun really, and got to the point I could ace the second tier practice tests all day. It got me really excited about radio in general, and today is one of the first nice days we've had outside and I regretted not having any equipment, so I ordered one of these cheap USB receivers for use with software-defined radio.
Anybody else ever play with one of these? Not expecting too much out of it, but I'd like to be able to listen to locals on a few bands, maybe pick up some satellite imaging, cw, other neat stuff like that. Tips, general discussion, etc.?
Wait, what is this? A HAM radio USB dongle that I can plug into my computer?
>>997570
It should pick up most RV in general, but I did get it mostly to try to receive ham. People use them for police scanners and to listen to FM as well.
>>997579
>RV
RF I mean. Can't type.
Good beginner antenna is a planar disk antenna http://www.wa5vjb.com/references/PlanarDiskAntennas.pdf
Get lna4all from Adam at lna4all.blogspot.com.
The rtlsdr dongle from the rtlsdr blog can be modded for bias-t if you get a bias-t enabled lna4all.
For decoding pagers encrypted with pocsag - (ambulance, emergency, etc.) https://www.bastibl.net/pocsag/
Also http://Reddit.com/r/rtlsdr
>>997537
You do realize this can't do the majority of HAM bands without an adapter right?
>>997769
Also this one is better. Doesn't drift like the other ones.
>>997769
Yeah but they're still great for starting out with VHF/UHF signals like 2m/70cm, aircraft tracking, weather satellite images, eavesdropping on pager frequencies, and so on, and upconverters are simple to build. (or cheap if you just want to buy one)
I have one works good for listening to the radio chatter at the hospital down the street from me.
I've used two of them to listen in on digital trunked radio, track airplanes, capture my whole neighborhood's electric, gas, and water metering, etc. You won't be able to get noaa sats with out a good dedicated antenna. All in all lasted about a month before I got bored.
Word of advice, don't waste money on one of the "100KHz-1.7GHz UV HF RTL-SDR" kits sold on ebay or chinaland outlet sites. They aren't real upconverters like they sometimes pretend. Instead you have to solder tiny wires on impossibly small leads coming from the rtl chip and use direct Q sampling to make it work. I used a soldering microscope and the finest tip i have for my hakko and it still took me several tries. Performance in the 100k-500k region is wanting. In retrospect I would have bought a straight 1mhz upconverter.
>>997763
>>997773
>>997781
>>997800
Thanks for the recs guys. Will probably upgrade when I get bored with what I have coming. I've got a pretty decent fun budget, so not too worried about economy, just easier to understand what I need and how to improve my setup if I start with something common, see its shortcomings first hand, and move on.
If you ever do pull the trigger and play around with ham radio, one of the cheapest ways to get into it right now is with these baofeng chinese radios
http://www.amazon.com/Warranty-Dual-Band-Improved-Stronger-Enhanced/dp/B00HX03AMA/ref=sr_1_1?s=electronics&ie=UTF8&qid=1464050241&sr=1-1&keywords=baofeng
If you are lucky you will be able to hit a local repeater with one of these (word to the wise, replace the included antenna with a better one). They are programmable so go ahead and pick up a programming cable because entering preset stations by the numpad is excruciating.
Also in regards to that usb reciever you ordered, you should buy an adapter so you can use real antennas with it. BNC is more or less the standard for a lot of antennas.
http://www.amazon.com/DHT-Electronics-coaxial-assembly-female/dp/B00CSCTU40/ref=sr_1_1?ie=UTF8&qid=1464050519&sr=8-1&keywords=mcx+to+bnc
>>997856
Yeah I've seen those, and it'll probably be what I start out with if I end up getting a license. Once I learn the ropes though, I'm pretty good with electronics already, and will probably build most of my equipment from components. That's a good chunk of the fun of it for me. Years down the road on all that though.
>>997856
>They are programmable so go ahead and pick up a programming cable because entering preset stations by the numpad is excruciating.
Not to mention saving repeater offsets to memory.
I know this is 4chan and sperg city so consider if ham is for you. Its one thing to be able to do the tech stuff but holding a conversation may be another. Digital modes may help.
I'm not hating on anyone here just making the point because I found CB was not for me. I think perhaps I'd be ok with some of the amateurs around here because its pretty civilised but I have heard the CA repeater streams and they sound like CB shit talking is in my country.
>>997885
Ham is not like CB. The conversations are generally handle, location, brief remarks of a personal nature. You don't go trolling and get beaten up by truckers on there.
>>997888
>Ham is not like CB
https://www.broadcastify.com/listen/feed/14747
>>997906
Naw, Playing guitar with an unshielded wah pedal, I get to hear about "stupid sumbitch dog" not getting fed or let inside in cold weather and what hookers have crabs in town all night on channel 19 interference.
>>997883
Yeah more or less what I was saying, programming in stations is just near impossible. Programming in bandwidth, power, frequency, offset, security codes. When I first got this radio it was borderline unusable until the cable came in.
>>997885
Yeah the CA repeater networks are notoriously bad. There's also 14.313 in the northeast and 3.810 in California. One time I heard a guy on 3.810 angrily yelling at somebody playing a Chris Rock CD.
Basically it can be as good or as bad as you let it be, just spin the dial.
>>997906
https://www.youtube.com/watch?v=JoeYmG7KDaM
https://www.youtube.com/watch?v=_BDAAp6e_d4
>>997957
That guy's accent in the second vid was fucking hilarious though.
Hello friends!
please consider checking out >>989158
we have a slightly different topic but there is some solid ham radio and assorted RF banter inside.
It's good to see so many nice radio threads these days!
ddddaa
Been thinking about picking one or two of these up and seeing if I can get them to work as multi-purpose aviation radios just for fun. I've seen projects where they're used as airband voice-com scanners, ADS-B receivers, and VOR receivers. Also within the SDR's range are ILS (both LOC and G/S), SSR and DME (though the latter two require two-way transmitting for their intended function).
Had tons of fun with my 5 euro dongle. cheap r820t from china.
Just beware , you have to buy one with the protection diode near the antenna plug (or put one yourself) or else you'll fry the dongle with static electricity (like my previous ones)
Amateur band, air traffic, 137 mhz meteo satellites, local analog radio repeaters used for taxi and private security companies,
ADSB at 1090
Here's in the pic a QPSK meteor m2 image i've taken last year
Also received really nice NOAA lrpt
With this dongle i've learned lots about building the right antenna for the right frequency , also learned about filters and traps .
>>998208
Would just any old rectifier diode work alright for protection?
>>998208
Shit I need to get back to this, it was the original reason I bought an SDR dongle.
>>998380
Hah me too then I fried the chip and gave up
>>998365
no, you need ESD diodes. (which probably are 99% in smd format )
It's easier to buy a dongle already equipped with that protection, many sellers show the internal pcb photo, and you can see if it is present or not.
>>997906
What exactly is going on here. Im listening at 4:30 and its fucking crazy.
>>998765
I was listening to it for a few hours the morning it was posted. There seemed to be a jammer spamming it with static for five minutes at a time, then the device would time out and he'd key it back in. Sometimes in between other guys would get on and heckle him.
>>998773
Ive been listening for the last hour or two.
Guy was doing poetry, another guy was singing a song about being gay, then some people were heckling a guy about beating his wife. Now they are checking in and saying what kind of weed they are smoking.
Im guessing this is a huge shitshow compared to most HAM stuff?
>>998719
Can't you just put a choke to ground.
>>998779
Pretty much. Repeaters tend to feature the lowest common denominators of ham radio. I'm sure there are quite a few people who got a technician license, and then lost interest in it after they turned on their new Baofeng and got a earfull of a local crank ranting about chemtrails.
For comparison, check some of the HF bands on here. Most of what you'll find is people doing distance contacts or talking about actual radio stuff.
http://websdr.ewi.utwente.nl:8901/
Hi radio thread ded?
>>999462
OP here, should get my receiver today or tomorrow. Will take it out and see what I can pick up if the weather holds up. Any quick and dirty software recs to just spin through a lot of frequencies with AM or something else simple?
>>997537
Hey Anon I'm looking at trying to get my hands on a radio frequency transmitter that can broad cast 11 hertz or 11 cycles per second. What would I need to be able to make this possible?
>>999629
>11 cycles per second. What would I need to be able to make this possible?
lots of wire. a quarter-wave antenna would be 6 million meters long. that's 12x the distance to the sun.
>>999659
What is the Woodpeeker frequency. Are you telling me the Russians had an antenna 6 million meters long during the 1960s? = _=
>>999661
a frequency range of 7 to 19 MHz, a bandwidth of 0.02 to 0.8 MHz, and typical transmission time of 7 minutes
>The signal was observed using three repetition rates: 10 Hz, 16 Hz and 20 Hz
It's transmitting 10 pulses per second on 7Mhz. Not something on 10hz.
>>999629
https://sourceforge.net/projects/audacity/
OP here again, some good news:
My toy should be here today, would appreciate recs for a simple Windows tuner app good for whatever this stock antenna can pick up, whatever section of the ham bands, shortwave if possible. I ultimately plan to be playing with the gnu SDR toolkit on an archlinux build I have running in a vb, but getting it to talk well to usb devices is a puzzle for another day.
Also I found a ham exam administrator in my area, so I'll get caught up on the new rules and brush up in general and probably test into a technician license this summer.
>>999967
Lol you could rig up a tuba horn to the throttle of a diesel engine and maybe do FM audio signal on a 10Hz carrier. No idea what the point would be or how well it would carry or how to receive it.
>>1000121
The active frequencies will be different in every area, man. Radio is local. Google for the local ham frequencies and the repeaters etc.
Not that I'm an expert, I bought my baofeng a year ago and still haven't heard a human (in Maritimes Canada if anyone can help)
>>1000175
>ham is local
Not totally true. DXing is a practice involving transmitting and receiving on frequencies that bounce off various layers of the ionosphere, allowing signals to go pretty much any point on (or off) earth from any origin.
>>999659
Brings up an interesting science question though. Disregarding the abyssal signal-to-noise ratio, would you be able to pick up a super-low-frequency carrier like this with an antenna a tiny fraction of the wavelength, like 1/(2^256) length or whatever a realistic length would be?
>>999659
>that's 12x the distance to the sun.
>6,000 km
Might want to check your math there.
>>1000261
According to my handy dandy calculator, the wavelength would actually be more like 60,000km anyway. Not quite as long as 1au, but unreasonable for a quarter-wave antenna on earth nonetheless.
>>1000262
That's it, I'm launching a counterweight to Alpha Centauri and picking up infracom signals generated by microscopic sentient life colonizing the vocal folds of tigers. Anybody have a schematic for the improved memedrive?
>>1000262
Still wrong. (299,792 km/s) / (11 Hz) = 27,254 km for one full wavelength.
In any case, 11 Hz was Duga's PRF, not its carrier frequency, so the point is moot. The Woodpecker operated in shortwave frequencies, at wavelengths between 15 and 40 m (which is reflected by the size of the emitters in the array).
>>1000272
Heh, you're right, must have made a typo. Duga was not what started this conversation in the first place though. It was a poorly worded question earlier, and it mainly just turned into goofy fun.
>>1000230
With modern techniques and the right modulation, you can pick up stuff below the noise floor (e.g. GPS).
>>1000305
The real question is about resonating an antenna at such a small fraction of the wavelength. I'm not sure EMR will even propagate through air at that low of a frequency, so let's just ignore the noise issue altogether.
>>1000181
True. He is, however, unlikely to be engaging in such practice at this early stage!
>>1000310
You can pick up shortwave and commercial AM from beyond direct line-of-sight with a consumer-grade antenna when the atmospheric/magnetic conditions are right, though, which is kind of fun an interesting itself.
OP here. Picking up local college FM radio after half an hour of fiddling. Using gqrx. Setup in Windows was a bit of a pain, but things are pretty intuitive from here.
>>1000313
Really!?!
I'll have to give it a shot. Is this the kind of thing that's pretty arranged on the net or something I'd pick up by hitting the scan button? I have a baofeng uv-5rb
>>1000410
I used to use these sub frequencies for VLF geophysics when we were mapping faults and veins
so im building a radio and its time for an antenna. i would like to receive multiple frequencies through the same antenna feed line [or more to the point, through one connector on the back of the radio.]
was going to build a dipole with four arms instead of two - the top for FM band and the bottom for weather band. both arms would attach to the balun at the same point.
would pic related be a sane idea to try?
would i still need an inductor and tuning capacitor if the antenna is already tuned for a given frequency?
OP reporting in.
Did a lot of testing last night and found the limits of the device in the OP image. The stock antenna will receive pretty well from about 24MHz up to around 1.2GHz. It has exact points where it will just break into hard noise beyond them. The software I'm using has a waterfall display and will demodulate any signal to four types of FM, AM, and both SSB modes, with a couple of CW filters thrown in for good measure.
I had no problem finding every local commercial FM station, indoors, under pretty harsh conditions. I also found a few FM broadcasts in the shortwave band around 30MHz. They were mostly music. Found a church broadcast on there this morning.
There are actually a lot of other things going on within the range it'll pick up. I could see signals in several ham ranges, CB, aviation and satellite frequencies, but they were mostly either data or what I'd call "dead carriers," like just a steady whistle or static no matter what demod mode I tried. On one space-to-earth frequency I could see what looked like a strong, speech-like FM signal, but for some reason I just couldn't tune into it. Wrote the frequency down and will try again tonight about the same time.
I found a couple of mechanical sounding signals that alternated between a few different sounds, not totally sure what they were, but wrote them down too and will study them a bit.
All in all, not to terrible of an entry-level device, does most of what I wanted it to do just starting out. The audio's a little choppy, not sure if it's software or hardware, and later I'd like to be able to go down into the rest of the shortwave broadcast band and commercial AM, but probably need a longer antenna for that. The one it came with is maybe 4-5", haven't measured, but really short.
>>1000505
Scan around the AM band (530-1600kHz) and the shortwave (1-~30MHz) at night when the sun's behaving. Shortwave is supposed to usually be AM as well from what I've read, but I've been finding nothing but FM broadcasts so far myself. You'll probably have best results picking stuff up longitudinally close to you. If you're in the Eastern US, Cuba does an international broadcast that's supposed to be fairly easy to pick up, you should be able to find the frequency on wikipedia, and I've heard of people getting AM from Brazil.
>>1000720
>I also found a few FM broadcasts in the shortwave band around 30MHz. They were mostly music. Found a church broadcast on there this morning.
Are you sure they weren't harmonics from FM stations?
>I found a couple of mechanical sounding signals that alternated between a few different sounds, not totally sure what they were, but wrote them down too and will study them a bit.
Could have been pager frequencies. Hopefully you'll be able to find them on this site:
http://www.sigidwiki.com/wiki/Signal_Identification_Guide
http://www.sigidwiki.com/wiki/POCSAG
http://www.sigidwiki.com/wiki/FLEX
>>1000812
I'm thinking they may be commercial relays from somewhere for normal FM stations. I'd expect harmonics to be in the 40-50-something range. These are in the upper end of proper shortwave.
Whatever they are, I'm pretty sure the programming isn't local. None of it matched up with our normal FM stations in town.
>>1000720
Also, question if anybody would know. I talked to some local hams and know where their repeater is, but it's a little below the range of my setup. I've heard a little bit of traffic on some other frequencies locals commonly use, but like one guy said above, no voice or anything.
CB on the other hand I'm a little surprised. I could see all the stations lined up in a row in the waterfall last night, but there was nothing on a single one of them. I know for a fact there's active CB traffic right near my house. It's always interfering with other audio gear I have. I tried listening to them in AM and SSB, and got nothing. Was it just a quiet night, or am I doing something wrong/lacking equipment there?
>>1000812
>http://www.sigidwiki.com/wiki/Signal_Identification_Guide
Is being very handy right now. Think I have found a very active golay pager. Been listening to it for a while now.
>>1000887
And holy shit I just got a two second burst of Morse Code in the 153MHz range. Been listening to this thing that makes a fart sound on it every five seconds and the Morse just came up out of nowhere.
>>1000720
You are using an SDR, right? Those "dead carriers" will likelly be the device's harmonics. You can reas about those sdr frecuencies on guides online. A trick to know if its a real carrier or a glitch is to change the frequency up and down while watching on a waterfall. Glitches will drift when you swipe over them. Also, there are programs to decode many diferent digital modes, even CW. Check those out
>>1000944
I've got decoders for CW and SSTV, anxious to use them. Kicking myself I didn't have the CW one ready when that burst came in at >>1000890.
Will be listening on that frequency more for sure.
I've been hearing a few other digital modes tonight, not familiar enough with them to recognize them, and I'd go nuts trying to find a decoder for everything I hear right now, but I will ease into it all. Having a ton of fun with this already.
>>997570
>>997769
>>998779
>HAM
Picking up CB tonight too.
>>999661
YES its just not in one big length
>>999629
A practical short range transmitter would use magnetic field, that is, large coils in both transmitter and receiver.
Long range ELF transmitters have been built using earth dipole antennas. Russians still have their 82Hz system running. Apparently it uses two 60km long antennas and around 10MW of transmit power (and around 10W of effective radiated power) to achieve global coverage. The old US system used somewhat less power and bigger antennas to achieve the same.
https://en.wikipedia.org/wiki/Ground_dipole
>>1000230
Even the transmitter antenna is bound to be a tiny fraction of the wavelength. The systems above are/were for communicating with submarines, which have even tinier antennas. Efficiency of such "tiny" antennas is naturally ridiculously low.
On a sort of related topic, what's the best radio scanner for under $100? I've got a couple Baofengs but the scanning mode on them is painfully slow and I'd like something I could set up to quickly scan the local police/fire or non-repeater 2m/70cm frequencies.
>>997906
>4:20pm bong hit net
This is gold.
Just get a Baofeng UV-5R and a book on the basic amateur license.
>>1002458
>one week later, heroic anon solves all our problems
Get you discone antenna, they pick up a large range of frequencies. Also, when you get your ham ticket, you will be able to transmit multiple bands. Google MFJ-1866 to see what I am referring to. 73
Is anyone here familiar with the Sony ICF-2010?
I found one on the sidewalk here and took it home, didn't power on but I googled it and found out it was just a broken connection to the battery compartment. In that searching I also found out this thing seems pretty valuable/does a lot of seemingly cool stuff.
I've been pretty interested in this sort of stuff for a while, but I've never really known exactly where to start. I live in the city so I don't have a yard or roof access for any fancy antennae but I do have a sailboat with about a 60 foot aluminum mast...
Anyway, radio for true true beginners, where to start?
HAM resources?
I'm in NYC, anything cool happening on the radio here? Surely there is, right?
>>1002647
>Anyway, radio for true true beginners, where to start?
Essentially you need to understand that radio waves under 30 megahertz bounce off of certain layers of the earth's atmosphere based on solar conditions and the time of day (lower frequencies are better at night and vice versa, though most broadcasters stay under 20mhz), allowing for radio stations to have global reach depending on how much power they're putting out. That will pretty much cover most of what you need to know before you start getting into stuff like antenna polarization or tropospheric ducting or whatever.
http://swling.com/QuickStart.htm
http://www.short-wave.info/
http://www.shortwaveschedule.com/
http://www.primetimeshortwave.com/
http://www.worldofradio.com/
http://www.dxing.com/
https://en.wikipedia.org/wiki/Radio_propagation
>HAM resources?
The ARRL technician handbook would be a good place to start.
One thing to keep in mind is that you're really going to be picking up a lot of stuff over time, so just keep asking questions and googling stuff. Though one suggestion I'd have is that if you're interested in shortwave band ham radio stuff, study for both the Technician and General class license at the same time if you can, because Technicians only get CW privileges on the shortwave bands and are otherwise mainly limited to walky talkies and a small chunk of the 10 meter band.
>>997763
Did the math on a planar disk antenna. Unless I made a conversion error, the lowest frequency response for 18" disks would be around 150-something MHz? The stock antenna on this cheap tuner goes down to 24Mhz itself easily. Anybody have a design that will cover the rest of shortwave and AM (even lower if convenient), or would just a long ass wire be the way to go?
>>1002686
Yeah I was wondering if you could test straight into general if you can pass the test. All of the practice tests on hamstudy.com seem to be a piece of cake after a week or two of drilling.
>>998180
I live under the landing path for a regional airport about two miles away, and picked up voice from planes and the control tower all week this week. It was a little choppy and unintelligible though, and very weak from high altitudes. A more directional antenna might help with all that, but these dongles will at least pick up aviation band.
>>999629
http://www.rtl-sdr.com/receiving-vlf-pc-sound-card-miniwhip-antenna-saqrx/
http://www.qsl.net/dl4yhf/vlf_rcvr.html
>>1002782
Or here's an idea, the ratio is about 1:6 regarding how bad the planar disk would be compared to stock.What if one were to make an array of 16 disks, 8 for each pole. Would the gaps be additive and increase the range to below 24MHz?
Another good question would be can the dongle hardware even handle anything below 24Mhz without an upconvertor?
>>1002809
>16 pizza pans hanging from a tree.
>My HOA is gonna kill me.
Investigating small loop antennas now. They apparently are good at directional reception at <=.15 wave. If the hardware can handle it that might be something more practical for what I'm trying to do.
>>1002835
Fun reading in that dept btw if anybody else is interested:
http://www.dxing.com/tnotes.htm
>>1002835
>They apparently are good at directional reception at <=.15 wave.
Not reception, but directional null. There's a BIG difference.
>>1002904
By good I mean capable at all. Aware of their directional null virtues, but I'm not exactly doing any direction finding or anything else it'd be good for right now. Looking into them as an option for M-SW receiving beyond the capabilities of the stock NOOElec antenna.
>>1002792
People regularly go all the way to Extra in one shot. Technician and General are about the same level of difficulty IMO.
>>1002979
That was about my impression when I was studying last summer. Extra was a little more challenging for me though. Seems like there was less I could actually memorize and had to actually learn something. Might have a better handle on things now that I'm actually playing with this stuff hands on a little though.
OP checking in.
Been trying to get various software packages running and seeing what the advantages of each are.
First program I used was gqrx. It's very stable and pretty full-featured. The only real disadvantage I've found in it is constant buffer underruns at every sampling rate and buffer length, which was what was causing that choppy audio. It won't let you set it to a happy medium where everything syncs up right. If not for that It'd be the only program I use for now.
Got CubeSDR running last night. Much smoother audio, as good as a hardware radio, and the tuner controls have a lot better feel and faster workflow for tuning into weak stations. It lacks the ability to bookmark or program in channels as far as I can tell, and lacks the CW modes gqrx has, but has DSB, which gqrx does not have. Also it crashes constantly. Gonna continue playing with it for a while.
I discovered direct sampling mode, which allows reception at frequencies below spec to some degree. I can see AM and SW stations and the lower ham bands this way, but can't seem to demod audio out of them other than carrier hums, even if the actual signal is visible in the graphs. This might be where swapping antennas comes into play, but I haven't gotten around to it yet. Direct sampling mode also screws up demod above 24MHz, so it's useless to leave it that way for random exploration.
There are a few other soft workarounds, such as switching drivers, etc., but I haven't had any luck in that department.
Tried to get started working with the gnu-radio tools, but the installs I have are extremely buggy and don't do much yet.
>>1003534
direct sampling mode is a shitty hack and you're better off buying a downconverter if you wanna listen to HF
>>1003536
Yeah I plan to in the future, just haven't gotten to that point yet. The dongle I have does seem to have some extra hardware in it already, still investigating and seeing what exactly it's lacking before I buy anything else.
Remembered I had a cheap old radioslut SW antenna I tried to build a theremin around once. have a piece of hookup wire tied to it and screwed in with the stock antenna. Pops the gain way up and knocks out FM a little below 30MHz. Listening to hams at 26.5ish right now, which I couldn't pick up before. Got some CB from about 30 miles away a second ago too.
This look like a decent upconverter to anybody? It's a super simple build, looks like well under $20US worth of parts.
https://lh3.googleusercontent.com/-HiLF3aA7fhc/URtosAs_ZhI/AAAAAAAALts/1o2VVvM3apo/s1600/HF%2520Upconverter%2520Design%2520with%2520Copyright.jpg
Anybody ever try getting the HF broadcasts of weather sat images?
http://www.nws.noaa.gov/os/marine/rfax.pdf
http://www.w1hkj.com/FldigiHelp-3.21/html/wefax_page.html
>>1004417
I was trying to while playing with direct sampling mode on my rtlsdr, but I couldn't see any signals at the right frequencies with this shitty antenna or get anything to demod anyway below 24MHz.
fldigi is a super fun program to mess with anyway. It'll decode all kinds of digital modes, analog tty, and cw pretty well, as well as encode samples so you can know what they sound like.
Disassemble that antenna that comes with the dongle and build a disk planar antenna out of two pizza pans from the dollar store. Spend the two dollars for the upgrade, you'll be happier.
>>1005483
>I come from reddit and did not read the thread
