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For the discussion of electronics, tinkering, radio, amateur radio, and related electromagnetic phenomena and communications.
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File: 1425522766479.jpg (17.21 KB, 240x160, 3:2, man-headphones-configures-….jpg)

Have an excellent day.

List of some Ham Radio activities:

http://www.qsl.net/w2vtm/hamactivities.html

http://www.arhab.org/

Resources:

Component and parts sources:

http://digikey.com

Flat rate shipping. Great for transistors.

http://www.mouser.com

http://www.elexp.com/

^ Good prices on silver mica caps/ 1N34A diodes/ if American.

http://allcan.com/

http://www.minicircuits.com

Good mixers/ amplfiers/ etc.

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No.991

>>990

Perfect!

File: 172e2c03bb1a7a1⋯.jpg (232.59 KB, 1258x754, 629:377, oscillo-mode.jpg)

Just what is the state of the art in advanced ham communication techniques and digital modes? I have a specific reason I'm looking in to this, and to be honest, I am not even certain of the correct terminology. Most ham stuff is either code, simplex voice, or occasionally full duplex voice, either with SSB and offset frequencies, or some digital technique (I think DMR tier 2 can do this on one frequency by using TDMA?). The limit here is that 2 people max can communicate simultaneously, although others can listen in. Commercial and mostly proprietary tech allows much more. So, what I'm interested in might be called "multiplexed" voice… the ability for more than 2 people to simultaneously chat on the same "channel"… presumably on a single frequency or some spread spectrum technique. Every member of the group can speak and listen and hear everyone else, and be heard by everyone else. I know there are bluetooth modes that allow this, and proprietary longer-range tech, like the Cardo PackTalk for (primarily) motorcyclists. Does amateur radio have any modes that compare? What advice does /hamradio/ have for a guy with an extra class ticket and a fondness for traveling on 2 wheels?

No.1189

>>1187

There's no mainstream technique that I'm aware of (beyond some speculative stuff associated with 5G cellular, and that seems to be fun and games with polarization that's only viable at SHF over short distances) that lets multiple stations transmit on the same frequency at the same time and simultaneously receive every other station.

Most existing techniques for doing this rely on some central facility that receives individual transmissions on diverse channels, mixes them, and then provides a single downlink stream. It's easy to imagine a system for doing this "over the air" via TDMA and/or FDMA, which is most likely what the Cardo system is doing, but those systems all have fundamental limitations when it comes to the number of users and the system topology.

There's not usually much amateur or professional radio interest in this technology for medium or large scale applications, because human beings can only reliably hear one person at a time.

No.1190

File: 45a0af0cbbc5eea⋯.jpg (704.07 KB, 1122x1243, 102:113, 1392577433618.jpg)

> There's no mainstream technique that I'm aware of

There's one called 'go to another frequency' that lets several people have several conversations at the same time…

The Bluetooth example: that's 3-4 channels of communication into 1MHz of bandwidth… or you could just divide the 1Mbps into ~40 16K0F3E channels.

File: 9ff447026a5d256⋯.jpg (220.89 KB, 964x632, 241:158, article-2527641-1A39278D00….jpg)

When the final nuclear war comes, what are you going to do via shortwave? Are you going to mantain Global communications between America-Europe-Asia? Are you gonna sit back and just watch, or will you try to help society rebuild?

1 post omitted. Click reply to view.

No.1058

Get on 6666kHz and 10420kHz and cheeki breeki with the surviving ruskies. Maybe with some 3400kHz AM thrown in and 3900kHz EC thrown in.

No.1076

Everybody radios will be dead from EMP, except those who have vacuum tube (valve) radios. But then no one will have the power to run one. And who will listen?

No.1092

>>1076

The dreaded emp is still just the same kind of electromagnetic radiation your radio was designed to detect. Just too much of it. Keep your antenna and power connectors capped off and/or put your radio in an ammo can.

Most military radios today are tested to withstand a typical nuclear EMP. It’s not a death ray that will wipe out everything electrical.

No.1117

>>1092

On the bright side, it'll sure clean up the airwaves.

No.1188

>>1076

Yeah, no.

File: 921585a9d755a13⋯.jpeg (74.48 KB, 989x469, 989:469, ya.jpeg)

What are some fun amateur frequencies to talk to strangers on?

No.1186

Channel 1 on FM PMR446

File: 1419382689795.jpg (2.53 MB, 4160x2340, 16:9, 20141108_221000.jpg)

Anyone here do any homebrew?

-Mod edit- 2015/11/08

This thread is dedicated to homebrew.

23 posts and 14 image replies omitted. Click reply to view.
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No.1120

File: dd174ed4eef944a⋯.jpg (167.19 KB, 1024x728, 128:91, 20190303-090555-resistive-….jpg)

File: 95008146b73a249⋯.jpg (210.67 KB, 1000x833, 1000:833, 20190303-090650-resisitive….jpg)

File: fcc23af4f3558c8⋯.jpg (147.58 KB, 799x1000, 799:1000, 20190302-142113-resistive-….jpg)

File: dcf68e1a90ec2e3⋯.gif (26.8 KB, 993x438, 331:146, resistive-swr.gif)

Like a regular SWR bridge, except doesn't actually measure the Ratio (actually just the difference in impedance). Very good for using with antenna couplers, and often used as a cheap alternative to antenna analyzers when portable (no battery, generally small and light, and don't have a lot of parts to go wrong/burn out– easy to DIY too). It's what VK3YE's Youtube channel as covered a lot of lately…

This one's got metal-oxide-film resistors, but they're rated to 7 Watts, and they're reactance-flat to use on the HF bands. All-up, it's probably good for 15-20 watts temporarily (i.e: when tuning).

No.1121

File: 166c4c9235334a7⋯.jpg (203.63 KB, 906x800, 453:400, 20190216-185707-wspr-in-a-….jpg)

>>1084

QRP-labs is for fags. (Says the fullchanner using Adafruit parts..)

The local WSPR guys are a storm of flying credit cards buying up QRP-labs U3S kits. I've halfway-completed this atmega328p-based beacon based on the breadboard project, using the Etherkit weak-signal mode code at https://github.com/etherkit/JTEncode

The bit at the top is a second-harmonic-optimized low-pass filter, removable for changing bands.

Then there's a SI5351 DSS, a 3231 RTC, and a bare atmega328p.

The battery will go underneath the matrix board.

The SIL headers are for programming and recharging.

Coupling the dipole antenna will go through a 1:1 current balun. The '5351 has an output impedance of 50 ohms, which is helpful. The output power is software-switchable from 2mW to 10mW.

No.1124

File: 0a300d2ab1906ed⋯.jpg (193.46 KB, 1208x800, 151:100, cw-trainer2-unzip-for-sour….jpg)

The latest completed project: A fancy-smancy Arduino-based Morse practice trainer. Nothing at all special about it, it's exactly what it looks like (Arduino + 4-bit LCD + key-in + piezo-out) except maybe having built it in a single afternoon.

It started off as a hack of what was posted by HB9TWS on radio.cc (site is gone.. The archive.org copy is at https://web.archive.org/web/20180526162309/http://www.radio.cc/post/morse-trainer). Stefan's work was just a (straight-key) decoder, but I've added a morse drill.

It starts off with 'the 100 most common words in CW', but the testing pool can be changed by keying in "TEST1", "TEST2", etc., to get single letters, single letters 'with a cheat', long words, and symbols. I've tried to make it as comfy to use as possible (no hasslin' for making mistakes..), unlike other practice software I've seen.

There's also a basic Copy practice mode– keying in (say) "20WPM" makes it beeps the words from the current test pool continuously, where would try to write down what it's sending.

Sidetone changed with the likes of "50FRQ" for 500 Hz.

Source code included– its using that concat trick, so just unzip the image (perhaps after renaming the extension to zip first.)

No.1181

>>1081

Tried adding more capacitance in parallel to the variable cap to push the resonance down?

Ould be just a piee of RG58 (QRP) or RG213 (100W and down).

>>1120

I did build a resistive VSWR meter as a new ham. Ony had a dual band HT and no money, so I made my own.

Used the "homo ludens electronicus" resistive bridge design.

No.1184

>>1181

>Tried adding more capacitance in parallel to the variable cap to push the resonance down?

Yep, I got around to trying out ~30cm/30pF of RG213, but didn't achieve much.. That antenna is kinda retired now that I've made up dipoles with neato kevlar-core copper(braided) wire.

File: d3b19ef2b7f29de⋯.jpg (171.13 KB, 1184x1500, 296:375, 81 s5VwqdQL._SL1500_.jpg)

How is the baofeng UV5RA Radio for getting started, and learning the basics for a Radio Licence? Is there a better one for that price?

I am just expecting to listen to all the frequencies and understand ham radio stuff, not to talk.

and by better, I meant one that you can progress your knowledge quite far with, and or has many features to potentially explore.

Thank you

27 posts and 3 image replies omitted. Click reply to view.

No.1167

>>1166

Was going to replace it with something..

"your mom lets you eat two baofengs" actually sounds funny now.

No.1168

File: 82cdfb14b275bdc⋯.png (2.05 MB, 1625x1600, 65:64, the joke is chinkshit.png)

No.1169

>>1168

Radios need antennas, you fucking Technicians.

No.1171

>>1163

>Gee Bill! How come your mom lets you eat you baofengs?

Eating? These are going up my ass.

No.1183

>>962

>>968

The cheaper transceivers' frequency starts crawling when you have a slightly longer QSO, and the rigs have shit RF protection. Also, the cheaper the rig is, the more spurious emissions they transmit, usually. And the manufacturers often claim that their cheap rigs have some BS marketing features, like a hand-held that has ~10 W of TX PWR. The Wouxun/baofeng UV5R and baofeng UV-82 are pretty much the only good cheap transceivers. If you want to get a HF/Multi-band rig, you should buy a second-hand one.

File: 1846fee4636e1ba⋯.png (18.25 KB, 300x288, 25:24, ClipboardImage.png)

Any aspects of Ham Radio that you despise?

I, for one, think digital voice is pointless. Yes, yes, I know the advantages, but I still hate it.

24 posts omitted. Click reply to view.

No.1140

YouTube embed. Click thumbnail to play.

>>1139

Ha– moments after posting, a video of that appeared on YT.

…unfortunately, it stops half-way through the questions (when a CCARC guy came in and announced the winner of the door prize, and Rowe bitched about the loud noises next door..)

No.1143

>>1138

>Well for hamband stuff extreme range IS a plus.

Yes, but neither D-STAR nor Fusion are 6.25kHz wide. That line was directed at NXDN anyway.

>Then build the systems?

I'd love to, anon, but radios are too expensive for me to embrace my inner NEET and work on something like that full time.

No.1152

YouTube embed. Click thumbnail to play.

>>1140

Now with more FreeDV 2020 on-air demo

No.1178

>>1133

Yep, especially when they (the japs) have a 1500MHz TDMA trunked network (weird system distantly related to MIRS/iDEN).

Australia is ditching their public safety TETRA and replacing it with P25 Phase2 system from Motorola.

>>1143

MMDVM can use old mobile radio that FSK well or ham rigs with 9600baud packet port (flat audio).

Just building that for some garage DMR or P25 repeater can be a starting oint for experiments and later testing on ading freeDV.

And peole have stuffed 2400A thru annalog HT's.

But yeah I can understand that there's never enough time to work on something like this.

But even a bad kludge with some documentation might inspire others to continue the work.

No.1182

>>1086

imo, having a license exam is only a good thing but there should be only 1 or 2 license "tiers" or "types". Having a small barrier to entry is pretty much required because what >>1087 and >>1088 said. Also, passing the exam and getting the license proofs that you have at least some technical knowledge and you know how to operate your rig and know the standard parlance and terms.

File: d241b8c17a162a8⋯.png (21.54 KB, 220x293, 220:293, afcd3f76cab32e4.png)

Evening gents, wasn't sure where to stick this thread, either in /tech/ or /hamradio/ Decided to go with this section as a lot of folks are already talking about UHF,VHF and Microwave.

Let's swap some stories, shit on hardware (or show some off) or w/e else you people do out there.

2 posts and 2 image replies omitted. Click reply to view.

No.1129

File: 50ae3bcc17e695e⋯.png (629.76 KB, 640x480, 4:3, Tuning_Screw.png)

File: 39cd5c93558ede4⋯.gif (2.95 KB, 382x273, 382:273, 2.4GHz_Filter.gif)

Ha. Makes me think doing microwave with scrap is possible..

No.1130

Anyone try out cnranger?

No.1131

File: 1806933be1c156e⋯.png (5.04 MB, 2048x1340, 512:335, 123456789456123010110.png)

No.1132

>>1130

Sounds fun, but unfortunately I'm not my own WISP, and I don't think it's going to be readily adaptable to HAM bands.

No.1180

>>1129

Yeah microwave's is where it stuff starts to literaly become plumbing instead of traditional electronics.

File: 04063b766b48bee⋯.jpg (62.21 KB, 800x800, 1:1, 800px-Telstar_satellite-Cn….jpg)

I am not yet licensed and I had a question reguarding sattelites. Television sattelites such as Galaxy 1 are now decomissioned/retired and are in a state of limbo but still in orbit. Is it legal to turn these sattelites back on and begin transieving on them? Galaxy 1 is still in orbit, but it is marked as "retired".

Telstar 1 and 2 are also in orbit. Would it be illegal to broadcast on these if you were able to bring them back online?

No.1111

It would be, because the frequency bands are re-used on new satellites and thus you would interfere with them.

In general just transmitting on those bands, even unsuccesfully would be illegal.

And if you want to pirate voice coms, there are better thargets like the 255MHz US Navy milsats. And more or less all the TV satellites have some unused transponder capacity at the edges.

Just be aware that pirating satellites IS posecuted in usa an milsat pirats have gotten rather large fines.

Most pirates for those systems are in brazil and russia.

No.1123

>>1111 (reluctantly checked)

These Satellite frequencies ARE available on a technician's license.

No.1141

but why do they retire working hardware?

No.1142

>>1141

Because they now have hardware which sends more data over the same (frequency) bandwidth. Why continue to transmit 1 megabit/s when you could transmit 100 megabit/s for only twice the price?

No.1179

>>1123

Hamband stuff yes.

ANd the ulink to the ryskiye Meridian UHF transponder <;)

>>1141

They usually don't. But you have th have enough fuel to push it to the graveyard orbit. You dont want it drifting there in that orbital slot for eternity when it dies, as GEO slots are very sought afther, and if you eave it there you'll never get launch or frequency permits for new sats.

The new sats usually have more power, more band width and more sensitive receivers.

So you get better SNR, more stuff via it and the end users can use smaller antennas or get more reliable service.

YouTube embed. Click thumbnail to play.

Ouch.

>$CURRENT_YEAR >US$2000

>no TXCO, and wobbles that fucking bad that digital modes are unusable on VHF/UHF/SHF

>with bonus Microsoft-standard firmware quality

No.1155

>>1154

Watch the video Hamchad. That external 10 MHz calibration can only be done from the menu (..and then starts drifting immediately). It doesn't lock to a continual reference signal like most rigs of that price band would do (IC-7610..)

The guy I know who bought this lemon has gone back to using his FT-818 (1/4 the price..) and the drift there is only very rarely worse than 1Hz.

No.1156

>>1155

I did watch the video. They didn't explicitly mention why they weren't using the 10 MHz reference input to lock the local oscillator, only made vague allusions to the IC-9700 "not able to be GPS locked". Given the nature of most appliance operators, that could mean almost anything.

You have to dig quite a bit to find that the "10 MHz Reference Input" on the back panel is only used for the self-cal feature, and doesn't actually lock the local oscillator. Icom doesn't even mention that in either of their transceiver operator's manuals, which is a bitch move on their part.

I could understand doing that on an HF rig, where manual tuning is expected, but it's fucking ludicrous on an exclusively VHF/UHF unit that's being sold as the best on the market.

No.1157

If not afraid to void the warranty:

They can use a GPS disciplined crystal oscillator,

Have more thermal mass around the reference crystal,

Build a crystal oven for the reference crystal

No.1158

>>1157

The thermal insulation tricks were tried, as well as a mod to the fan. Didn't improve things much.

This guy <http://www.cortexrf.com.au/IC9700lock.html> has succeeded hacking external GPS locking directly to the internal oscillator.

No.1159

>>1158

Place one np0 capacitor as a thermal buffer on each pad. Dead bug style with legs sticking up.

The capacitance will probably lower the frequency.

Have the crystal inside a crystal oven at a stable temperature higher than 40Celcious to bring the fre…

Having just typed all the above I googled the board…. Wow, what a small crystal. No wonder it's susceptible to thermal drift. It looks like a pain to get a crystal oven in there too… hmmm

props to the guy who locked the internal oscillator

Solder a beefier crystal in there? Way to save 20 cents I-COM

File: 3653e8bc3dc7aff⋯.png (257.58 KB, 699x750, 233:250, RBS0Wya.png)

Let this be the Ham jokes thread (aka an excuse for me to post this)

8 posts and 4 image replies omitted. Click reply to view.

No.1096

File: ef5a1359d882c11⋯.png (600.1 KB, 1063x759, 1063:759, h5mk6TV.png)

No.1113

File: 2105390b38e6fb8⋯.png (162.81 KB, 618x348, 103:58, boomerQRO.png)

>>1064

Ham radio + FTA satellite + cars

My yard is full of all sorts of homemade antennas BUD's Big Ugly Dish, and parts cars.

My neighbors don't talk to me much.

No.1135

File: 6fadb6849757ba2⋯.jpg (11.21 KB, 200x152, 25:19, jpfi2BH.jpg)

File: 81becc7e3285f8b⋯.jpg (40.73 KB, 429x360, 143:120, GXeDk95.jpg)

No.1136

>>1135

What does one call that ride?

The duke of health hazard?

No.1144

>>1136

Proof that the owner is… on the spectrum.

File: 1429802910549.jpg (252.03 KB, 1200x1600, 3:4, ant_ham-radio_n7eo_klm-kt3….jpg)

I've heard you can use HAM Radio in combination with certain software in order to send files between computers. What sort of software/hardware, and what kind of bandwidth are we talking about? Can it work for streaming video? Would the microwave bands provide high enough data transfer speeds?

10 posts and 3 image replies omitted. Click reply to view.

No.781

Here's a list of GNURadio examples for sending digital files and messages. I believe you can use an audio sink instead of software radio if you want to use conventional transceivers. You should be able to use hackrf in place of usrp, but you'll need an amplifier if you want to transmit beyond your neighbors.

No.790

>>779

Small/no images.

If/when we get our hamnet thing running It's likely going to feature YaCy distributed search engine, Asterisk/SIP, repeater linking, a wiki, some nostalgic fuck is gona host a BBS and I'm gona stuff up an imageboard.

No.835

Pskmail works for basic jobs, no video and slow data files. I used to use it before real internet arrived and while at sea. Its free..

No.841

>>835

>pskmail

Fantastic– finally a reason to get off the Novice/Foundation licence. Talking to boring normie strangers is a fucking drag.

No.1122

File: 1457335227096.jpeg (215.25 KB, 907x1355, 907:1355, image.jpeg)

Pray tell oh hams, WTF is going on here??

4 posts omitted. Click reply to view.

No.663

File: 1464017376973.jpg (123.48 KB, 880x813, 880:813, 1446654310_563a31662ca49.jpg)

>>662

I was going to say parallax but your fancy word is better as thats not really paralax.

Obviously the power lines are behind the house not directly on top of it.

No.698

>>627

with the stucco-foam house I'd say they live in southern california, a shitty place that is wtf as it is.

No.1114

File: 27df4045a55d92c⋯.jpg (68.78 KB, 640x480, 4:3, proxy.duckduckgo.com.jpg)

>>698

>with the stucco-foam house I'd say they live in southern california, a shitty place that is wtf as it is.

Ive never seen power distribution like that in the US. And that looks like a concrete telephone poll which is also not really used here.

Also the wiring mess on the pole kinda looks like the illegal hookup crap you typically see in the 3rd world.

No.1118

>>629

Except my lad, natural selection does not really work in the modern world. We've got bright scientists who die without reproducing, and 70IQ Africans having 6-9 offspring.

No.1119

>>1118

Evolution gives zero fucks about living in space stations– it's all about staying ahead in the race with the microbes.

File: 1432342355218.jpg (43.19 KB, 500x340, 25:17, 1335122230936.jpg)

So I happened along something today, apparently 14.313 has a reputation for being full of shitty and unlicensed operators, cranks, and shitty cranks.

Plug the number into google and the first few pages are full of nothing but reports of these kinds.

Apparently there's a russian guy in Canada, VE1KFM, who's known for being either completely nutty or a complete troll, not sure which. The USA hams hate him, and he's technically broken all the regs, but Canada refuses to do anything about the guy.

Google that call, and you'll see even more reports and some pretty humorous recordings.

Anyone else ever heard things about or on this freq?

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No.631

you know, for some odd reason, with my radio, I've never been able to pick up anyone on 14.313, are the signals too weak for my portable antenna? or do I just have bad timing?

but when listening to 27.025 however, I get plenty of chaos there, particularly around 0200 onwards.

No.635

>>631

I go on 27.025 and I just hear weird beeps

No.636

>>558

What a bunch of faggots.

>hurr these guys say MEAN THINGS they should go to JAIL REEEEEEEEEEEEEEEEE

No.637

>>635

THE NUMBERS

No.1115

YouTube embed. Click thumbnail to play.

>>635

>I go on 27.025 and I just hear weird beeps

Thats cb CH6 aka Da Bowl.

Mostly just redecks and dindu's running dirty 1-10KW amps yelling over each other on AM.

File: be96fb0bb02fc4f⋯.jpg (11.59 KB, 294x171, 98:57, images.jpg)

Have you ever encountered operators that talk the old days or just strange crap in general?

I am in close connection with an apparent legend from "The Liberty Net" his name is "Tommy-Tubes". If anyone remembers him you can reconnect with him on zello at

'the motley crews'

Working a VHF repeater in upstate New York when I was first starting out. I made contact with a 'Pastor', he hooked me right in simply because I was alone on the airwaves.

My major blunder with this guy was I gave him my personal phone number.

Since October of 2016 I have been close in with this 'Pushy-pastor-type'

An example of what life became for a while was…

2000 EST:

Ah! I shall go to sleep

2330:

*phone rings BBBZZZZZZTTTT*

Oh my this must be important, better go answer.

——————-

"WHY AREN'T YOU ON ECHOLINK SO WE CAN TALK ABOUT THE BIBLE!"

"[I know a washed out female singer from the 60's]"

——————-

Some of the Silver Linings to this is,

I got into the Bible.

I just stick around though to wait till he gets vanned.

No.1104

>>1098

holy shit, that's nuts.

The closet I got is an old dude in a nursing home. cool guy, rambles a lot but never heard anything terribly crazy or odd about him. just that he was old as hell (sounds like 80s/90s).

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