|
America posted:I did hook the antenna up to an SDR with a HF LNA and picked up FT8 from as far away as eastern Spain, Japan, and Chile (I'm in the US southwest). We'll see what's possible with 20W. Can you tell me more about your setup? I've got a HackRF that I'd like to do HF stuff with. Most of what I've found in terms of SDRs and ham radio is just SDR guts in a traditional transceiver body. I get the advantages of that sure. For me the advantage of an SDR is messing with the software though.
|
#
?
Nov 29, 2021 15:57
|
|
|
|
| # ? May 10, 2024 07:34 |
|
|
Forseti posted:Weird old portable Sony CRT hype! Yours is a lot cooler than mine though, I'm pretty jealous. I got mine because I wanted to experiment with creating analog TV broadcast signals and it's super convenient for that. I guess what I'm saying is, this find necessitates a new hobby for you, congrats! Ooh, how are you doing that? Mine isnt magnified at all, its just curved plastic in the front, it looks like a lens, but isnt
|
|
#
?
Nov 29, 2021 16:42
|
|
|
Jim Silly-Balls posted:Ooh, how are you doing that? Using it is as the carrot to help me learn analog electronics better  .I'm into retro gaming though so I conveniently have an NES sitting here that creates a ready to go broadcast signal on channel 3 or 4. I whipped up a crude amplifier a while ago that didn't really work all that well, I need to circle back to it and refine it sometime. Yours actually has an external antenna input it looks like so if you wanted you could make an adapter to the 3.5mm plug from one of those old systems that outputs RF, although a little transmitter may be more fun if you're into the journey more than the destination.  Obviously it's not transmitting very far, but it was cool to get a signal! It's even slightly better than just touching the center conductor of the coax coming out of the NES to the antenna tip, although that also makes something you can see at least if you wanted a quick and dirty test and have an RF signal handy. I have some fast transistors but that design above is Class C because I tried to adapt the PA stage of another project (FM radio transmitter) and didn't realize that Class C doesn't play well with AM signals at the time. I think I would have had a lot more luck starting with a simple Class A design and a high speed transistor and then going from there, and that's what I intend to try next. Trying to make it work with a dirt cheap SS9018 NPN (with an fT of ~1 GHz) but I have some faster 2SC4083 (fT 3.2GHz) and even some ludicrously over-specced BFU760F SiGe transistors (fT 45 GHz). Coming from a CS background, I've had a ton of fun learning about analog electronics though!
|
|
#
?
Nov 29, 2021 16:58
|
|
|
Forseti posted:Weird old portable Sony CRT hype! Yours is a lot cooler than mine though, I'm pretty jealous. I got mine because I wanted to experiment with creating analog TV broadcast signals and it's super convenient for that. I guess what I'm saying is, this find necessitates a new hobby for you, congrats! I remember reading about Franken-FM radio stations a while back, I’m betting that’s what this is all about. https://en.wikipedia.org/wiki/Channel_6_radio_stations_in_the_United_States
|
|
#
?
Nov 29, 2021 17:24
|
|
|
yoloer420 posted:Can you tell me more about your setup? I've got a HackRF that I'd like to do HF stuff with. Most of what I've found in terms of SDRs and ham radio is just SDR guts in a traditional transceiver body. I get the advantages of that sure. For me the advantage of an SDR is messing with the software though. Sure, the pipeline looks like: - roughly 40'x20' rectangular loop of insulated 18AWG wire built as per https://www.k4vrc.com/uploads/1/0/1/5/10156032/delta_loop_140918.pdf - 4:1 Current balun also like in the link above - cable run (gonna add a couple of lightning arrestors and ground rods before the storm season) - Nooelec HF LNA https://www.nooelec.com/store/lana-hf-barebones.html - RTL-SDR - Gqrx - WSJT-x I also used a NanoVNA to set up the antenna.
|
|
#
?
Nov 29, 2021 17:46
|
|
|
Stitch posted:I remember reading about Franken-FM radio stations a while back, I’m betting that’s what this is all about. Yeah we had one in Denver up until this or last year. Tejano music bumpin on the audio, screen saver for video. Pretty hosed up that iheart has such a death grip on the FCC that it was easier for them to keep an audio-only analog tv license up than to just get an FM one.
|
|
#
?
Nov 29, 2021 18:12
|
|
|
Stitch posted:I remember reading about Franken-FM radio stations a while back, I’m betting that’s what this is all about. Jonny 290 posted:Yeah we had one in Denver up until this or last year. Tejano music bumpin on the audio, screen saver for video. Pretty hosed up that iheart has such a death grip on the FCC that it was easier for them to keep an audio-only analog tv license up than to just get an FM one. Oh neat, I hadn't heard of this before. That may be what it is, I can definitely pick up the same audio on the very low end of a normal FM radio. The picture does turn blank instead of static near where I have it here to pick up the audio, but the audio is no longer coming through when the screen blanks 
|
|
#
?
Nov 29, 2021 18:38
|
|
|
The Washington DC area channel 6/FM 87.7 went off the air for a little while, but came back a few months ago with digital TV and analog audio. The television side is country music videos, the radio side continues with Spanish language pop. The analog FM signal is where the station's value is at sadly.
|
|
#
?
Nov 29, 2021 19:04
|
|
|
Yeah the audio subcarrier for channel 6 is 87.75 on the dot. Deviation is different (25khz vs 100khz for regular FM) so they come across as a bit quieter than real stations, but it worked for decades.
|
|
#
?
Nov 29, 2021 19:11
|
|
|
i can use my game gear tv tuner to pick up my rebroadcast somafm stuff from earlier. im planning on getting it set up to broadcast ds9 episodes, but haven't come anywhere close to getting around to it yet https://www.youtube.com/watch?v=bJGAdiV6_qc i talked about it in the yospos thread but dont think ive mentioned it here. i'm jusing a raspberry pi gpio pin to broadcast internet radio under part 15. i tune into that with my old radios (and also game gears) and it owns Achmed Jones fucked around with this message at 21:58 on Nov 29, 2021 |
|
#
?
Nov 29, 2021 21:55
|
|
|
Obligatory My V Dipole is now more solidly-constructed with a clip on reflector and the cable hidden up the pole. The only annoying thing is that I also use this antenna for weather satellites, and if I install the BPF/LNA that I have to boost the signal for those it’ll notch out the 2M ham band where the ISS lives. So I’ve made it easy to take apart to take that little board out when the ISS is in SSTV mode. Definitely can’t use this in the rain though as a result. Hopefully I’ll have a Yagi soon for more serious Tx/Rxing work, but having a kit + laptop I can deploy inside 5 mins for *pictureeeees frooommm spaaaaace* and then being able to sit back while it works away is really nice. thehustler fucked around with this message at 22:46 on Dec 1, 2021 |
|
#
?
Dec 1, 2021 21:04
|
|
|
Your definitely turned out better than mine, but it was pretty unfavorable pass here in southeast Europe:  Handheld log-periodic antenna fed into Yaesu FT-70D, lav mic next to radio speaker fed into the phone running Robot36. I'm pretty happy how it turned out, and apparently my antenna almost doesn't care when ISS is below the horizon.
|
|
#
?
Dec 1, 2021 22:33
|
|
|
It’s so strange when you can hear it before the pop-up time, I’ve had that even on a V dipole. And I think your cleanest shot is superb, I ruined mine by turning the antenna the wrong way when trying to improve the orientation.
|
|
#
?
Dec 1, 2021 22:48
|
|
|
Jonny 290 posted:the amateur radio hobby can be distilled down to folks that buy 99% refined copper wire and re-bury it in the earth i had to create a network of wires that goes along the walls at the apartment complex and everywhere under the porch. there were preinstalled coax hangers underneath where the wood paneling stops so that was an easy job. no one have noticed lol.
|
|
#
?
Dec 2, 2021 16:20
|
|
|
I can pick up KQED on channel 6, although I have to play with the fine-tuning a little: https://www.youtube.com/watch?v=cVyjafeBXYA
|
|
#
?
Dec 2, 2021 23:07
|
|
|
I made these christmas tree lights using WS2811 strand lights. They just flash pretty colors, but my dad suggested one should flash out morse code holiday messages, so I implemented that. It got me to thinking maybe some ham operators would appreciate a controller program that flashes THE ENTIRE TREE in morse code. Like, it'll pick a random light and start flashing out a message in one of the colors. This would all happen asynchronously, so there'd be like 30 lights flashing out different messages at any given time, all independent of each other. The overall effect would be twinkling, but people who are HUGE NERDS would be able to focus on a single bulb and get a little message out of it. It'd also be pretty easy to make a menorah do this, by flickering between bright and not-as-bright. I could even have it connect to wifi to get the current date and light the appropriate number of candles automatically. Before I launch into all this work, is there anyone at all ITT who'd be interested in such a thing? cruft fucked around with this message at 16:55 on Dec 10, 2021 |
|
#
?
Dec 10, 2021 16:53
|
|
|
cruft posted:I made these christmas tree lights using WS2811 strand lights. They just flash pretty colors, but my dad suggested one should flash out morse code holiday messages, so I implemented that. I just passed the CWOPS advanced course and would love to exert my new found CW authority over my holiday lights, sounds awesome.
|
|
#
?
Dec 10, 2021 17:38
|
|
|
Hey radio dudes, I need you to tell me my idea is stupid and why. So, I've had this crazy desire for a long time to build some kind of gadget that can "see" RF. Yes I know you can't see it, what I've always wanted to do was visualize what you would if you could actually see RF, and say for example gazed out towards an FM radio transmitter or something. I've got a bunch of free time coming up soon, so I thought of actually giving it a go. I've got a lot of experience in various tinkering, and right now here's my current thoughts. Build a 2 axis motion controlled tripod head style device, mount a very directional antenna on it hooked up to an SDR. Hell I've got most of the required hardware just laying around. Have an arduino or other controller directing the head to step through arcs through the sky, measuring the signal strength of X frequency at each step and logging it. Through software and converting from arcs to cartesian coordinates and converting the signal values to an image approximate what the thing "sees". I don't have a lot of experience with radio stuff, besides cobbling together an ADSB antenna for my roof. So I'm probably hilariously misunderstanding something here. If you rigged up such a system, does RF even behave the way I'm assuming? What my dumb rear end envisions in my head if you ran such a scheme would be something like a flare if you aimed it at a transmitter and only examined one frequency. Example:  Assuming you could process the input enough to discern a difference at each angle sampled, am I thinking completely wrongly, would there even be anything to see? Is it even possible to build an atennna directional enough to make this work? I'm thinking at the least an antenna that's restricted to a degree or two, and stepping through say 90 degrees of sky in both axes.
|
|
#
?
Dec 10, 2021 21:13
|
|
|
That's a fun idea. Beamwidth will be hard to hit over a wide frequency range. I would suggest doing a prototype with a directional antenna focused on a relatively high frequency band; 2.4 and/or 5.8 GHz would be great candidates as the wavelength is small so you can get a very sharp beamwidth with a pretty small antenna. After that it's just a matter of logging signal strength vs position and making your heatmap.
|
|
#
?
Dec 10, 2021 21:17
|
|
|
this is a homemade radio telescope, and it is cool rf is just visible light with a much longer wavelength. what you describe is a fine way to set rgb pixels for 650nm/550nm/450nm wavelengths; there's no reason i see that it wouldn't also work for 32.7/12.5cm/5.17cm (pace beam widthstuff)
|
|
#
?
Dec 10, 2021 21:31
|
|
|
Something that's pretty cool to do is to check out the hydrogen emission line, which you can use to see the redshift of objects over parts of the sky. This is a pretty cheap build of widely available parts that let you see a reasonably narrow part of the sky's hydrogen line. https://www.rtl-sdr.com/cheap-and-easy-hydrogen-line-radio-astronomy-with-a-rtl-sdr-wifi-parabolic-grid-dish-lna-and-sdrsharp/
|
|
#
?
Dec 10, 2021 21:36
|
|
|
Fortunately we have this humdinger of a radio noise source that you will see for several hours every day. Real bright, follows a well-defined path, and if it's daylight out it's guaranteed to be there! (moonbounce folks calibrate their antenna arrays with sun noise)
|
|
#
?
Dec 10, 2021 22:02
|
|
|
Jonny 290 posted:Fortunately we have this humdinger of a radio noise source that you will see for several hours every day. Real bright, follows a well-defined path, and if it's daylight out it's guaranteed to be there! If you're talking about my uncle Floyd, he stopped nude sunbathing every day after the 4th melanoma excision.
|
|
#
?
Dec 10, 2021 22:38
|
|
|
Enos Shenk posted:Hey radio dudes, I need you to tell me my idea is stupid and why. cool project idea! i wanna make you aware of some prior art in this area, if you haven't seen this before https://www.youtube.com/watch?v=g3LT_b6K0Mc this project took a long time to build an image, it would be cool to find a way to speed it up. probably need a large array of antennas for that.
|
|
#
?
Dec 11, 2021 02:36
|
|
|
Got to listen in on my first ARES/Skywarn net last night at about 3:30 AM. I gotta say, it is nice to hear someone calmly telling you that poo poo is hitting the fan only a few miles out and other stations checking in with their objective reports of power loss and wind damage. You may not have control of whats going on but at least the up to the minute awareness of the situation brings some comfort in knowing when the worst has moved past and you can relax your guard a little bit.
|
|
#
?
Dec 12, 2021 08:20
|
|
|
ISS SSTV end of year: https://ariss-sstv.blogspot.com/2021/12/ariss-end-of-year-sstv.html
|
|
#
?
Dec 14, 2021 23:11
|
|
|
Can somebody make software that takes signals from different sites and triangulate signals and show it in realtime in a 3d map of the area so you can see where radio signals are and their strength in realtime (preferably in VR). i await your work.
|
|
#
?
Dec 15, 2021 09:52
|
|
|
ya, this is a thing that exists (minus the vr) https://dk8ok.org/2018/07/25/direction-finding-first-experiences/ there are loads of software defined radios all over the world that are coordinated online. to the point you can ask a lot of radios what direction they think they hear a signal from and then lay that data down on top of google maps. its uncovered the location of things like number stations and pirate radio broadcasters.
|
|
#
?
Dec 15, 2021 14:02
|
|
|
Hey guys, I’ve got a bunch of stuff here that’s been sitting in a garage for 20 years. It should all be in the same condition it was 20 years ago, which is working. Do I have anything good, and other than the legal hurdles of getting licensed, how hard would it be to set up?
|
|
#
?
Dec 17, 2021 02:20
|
|
|
DONT PLUG IT IN* but yes you have a full ts-520 setup including a digital frequency display, external VFO ("tuning knob") and looks like a mic. That's a few hundo at least. But you should keep it, because it's cool as poo poo. * It's not because it'll explode or anything, but it's a radio with a couple of tubes in it, and it needs to be carefully revived so the ancient capacitors don't let out the magic smoke. If you're interested in getting your ticket you'll need a General class license to make full use of it, but if you can do that and find a local geezer to give it a once-over you got a fine start to a station there.
|
|
#
?
Dec 17, 2021 03:29
|
|
|
Jonny 290 posted:DONT PLUG IT IN* but yes you have a full ts-520 setup including a digital frequency display, external VFO ("tuning knob") and looks like a mic. That's a few hundo at least. But you should keep it, because it's cool as poo poo. I fully intend to keep it, and I have more than half a mind to get it set up and in working order. Although I need to do a good bit of research because on top of getting my license, I’m within the National Radio Quiet Zone. Although it being tube tech is a bit concerning. I think there’s a few extras out with the radio, but do they even make those anymore?
|
|
#
?
Dec 17, 2021 04:01
|
|
|
Buddy there is always a greybeard with the HAM parts you need
|
|
#
?
Dec 17, 2021 04:03
|
|
|
Yeah there are several chinese factories still cranking out the tubes, no problemo. As long as you get it set up and in working order they should last years. Plus there are tons of NOS bottles still floating around; these radios were incredibly popular so spares were commonly bought.
|
|
#
?
Dec 17, 2021 04:22
|
|
|
Thank god for the Chinese I suppose. I guess I’ll start thinking about where I can set it up at and start digging everything out and cleaning it up.
|
|
#
?
Dec 17, 2021 04:41
|
|
|
poo poo guys i made my first satellite contact today. What a milestone. Just wanted it on record in the thread.
|
|
#
?
Dec 18, 2021 16:31
|
|
|
Sammus posted:Hey guys, I’ve got a bunch of stuff here that’s been sitting in a garage for 20 years. It should all be in the same condition it was 20 years ago, which is working. Do I have anything good, and other than the legal hurdles of getting licensed, how hard would it be to set up? Oh hey it's my radio. I've got one of these (and so does Jonny 290, unless he's passed it along) and it's a fantastic-sounding receiver. In my opinion it picks up signals better (on the same antenna) than my TS-570S, with all its digital bits and bobs. Being a tube rig, there's more to transmitting than just keying up like you do on a transistor unit, but it's not too hard. This guy has a bunch of info on his site: https://www.k4eaa.com/
|
|
#
?
Dec 19, 2021 19:31
|
|
|
Still got it, though it's in storage. some day when i have bench space i'll break er back out. and yes the receiver is extreeeeeemely good
|
|
#
?
Dec 19, 2021 19:57
|
|
|
thehustler posted:poo poo guys i made my first satellite contact today. What a milestone. Just wanted it on record in the thread. Congrats! Which one, what mode, and using what gear?
|
|
#
?
Dec 21, 2021 01:10
|
|
|
America posted:Congrats! Which one, what mode, and using what gear? SO-50 with someone I know, M5JFS, who does a lot of sat work. A home-made DIY Yagi (based on the K6ARK design with no reflector, only I used tape measure segments) and an Anytone 868, so I did it without a full duplex rig, which is hard. The only way I could make it work was to listen until I got a signal aimed just right and was picking somebody up, then held in that position before I hit PTT. Seemed to work, got callsigns and locators exchanged but only just. You can see the antenna in here, cost me about £5 all together to make and is held together with literal sticky tape: https://twitter.com/markpentler/status/1471459419313500176?s=20 On Wednesday I'll try some more overhead-type passes and see if that helps. Or just use the ISS, but the issue with that is that the signal power is so strong you can basically get a signal on Rx by aiming at the drat ground.
|
|
#
?
Dec 21, 2021 02:15
|
|
|
|
| # ? May 10, 2024 07:34 |
|
|
This isn’t specifically radio related but radio adjacent. I picked up this oscilloscope. It’s a 2 channel 100mhz Instek from the early 00’s It’s in sort of a weird position where it’s straddling the older school design and the modern design for oscilloscopes. It has a CRT, but a really nice crisp late-era CRT, but it also has onboard compute capabilities, onboard storage, serial communications, video-out over VGA and stuff like that.  On the subject of serial communications it apparently speaks SCPI, which is a standard protocol for lab equipment like this. Is there any sort of software that will talk with this over SCPI, or am I stuck rolling my own? I received the manual with it and it lays out all of the SCPI commands that will work with it and I can slowly peck them into putty, but if there was some sort of graphical front end to make it easier that would be nice
|
|
#
?
Dec 21, 2021 17:33
|
|