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/hamradio/ - Electronics

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)

 No.180[Reply]

Welcome to /hamradio/

http://8ch.net/hamradio/rules.html

Have an excellent day.

LocalLink:

http://8ch.net/hamradio/

List of some Ham Radio activities:

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

http://www.arhab.org/

Youtube channels:

https://www.youtube.com/channel/UCPhfct0hwCpv_q6_BVSFsRA

https://www.youtube.com/user/w2aew/videos

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/

You can order from a dealer or your local radio shop

http://www.minicircuits.com

Good mixers/ amplfiers/ etc.

Post too long. Click here to view the full text.
25 posts and 37 image replies omitted. Click reply to view.
Post last edited at

 No.1090

test




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

 No.1048[Reply]

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?

 No.1049

>what are you going to do via shortwave?

Shitpost like I've never shitposted before.


 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.




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

 No.1079[Reply]

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.

14 posts omitted. Click reply to view.

 No.1107

>>1099

System Fusion is an abortion that should fuck off and die. It's a gimped P25 (this also answers why hams dont have P25 widely, because patents and license fees beyond the codec), but not compatible with P25 or any existing digital mode.

Even worse, it's not gimped Tier2 P25, it's the old tier1 one.

>>1100

freeDV with codec2 is 100% free, but the only "Production" radio with it are chinese clones of M0NKA mcHF, which includes I think 1600A version of freeDV. There is also one satellite with it.

>>1105

Nokia PMR division → EADS → Cassidian → Airbus Defence.

I have some Nokia and EADS TETRA handsets, strictly 410-430MHz only.

My Sepura TETRA's do 407-470MHz with good 70cm sensitivity, unlike 410-430MHz band motorolas hacked for out of band.

TETRA is now the "new hotness" for those of us liking weird stuff, same folks who used to run the P25 repeater around here.

Thankfully DMR won the ham digital voice thing here.

There's a couple of pockets of YSF due to cheap repeaters, but those are usually run in analog mode (or have blown finals).

The DMR network here also has parts of it's internet backhaul done by 5.6GHz hamband microwave links, so parts of it can stay linked even without internet connectivity.

The links and repeaters also have backup power.

I'm tempted to replace my MD380 with an Alinco DMR handheld. Dual band 2m/70cm DMR+Analog and made by a real ham manufacturer? Nice!


 No.1108

>>1107

>System Fusion is an abortion that should fuck off and die. It's a gimped P25

So Yaesu/Vertex did the same thing Kenwood and Icom did with NXDN? The Japanese seem oddly focused on 6.25kHz for some reason, which is weird considering that one would assume their domestic market would be ideal for TDMA solutions.

It's a shame your division got bought out by Motorola, given that they provided tech to so many other manufacturers.

TETRA is cool; it's a shame it never got much penetration in the US, because it'd be ideal for a lot of industrial setups. How are you guys setting it up to run on HAM bands? I've never seen much on the web about it's use in amateur applications.

Alinco's new portables all seem to be rebadged CCR's with some QA applied. Looking at the promotional images, I see the old familiar stink of Chinese firmware on the display. I hope I'm mistaken; we need an alternative to the big three.


 No.1109

>>1108

6.25kHs is more likely from USA narrow banding. first 25kHz to 12.5kHz and now 12.5kHz to 6.25kHz channels. DMR/MotoTRBO cheats by hving two timeslots in a 12.5kHz channel and thus qualifies for using "half" of the bandwidth as previous systes.

If by division you are refering to the Nokia PMR division, it did not get bough by Motorola, they bough a tiny part that did dispatch software or something like that?

Makes sense considering they bought the UK govt Airwave TETRA network.

We have a couple od DMO (single channel TDMA) repeaters for 70cm experiments and are planing on internet linking them.

The Danes and Germans have larger amounts of linked DMO repeaters and the germans have one TMO (proper full duplex TETRA base station).

For hamband TETRA we use 70cm and mostly Sepura's and Motorolas. There is also a hobbyist network on commercial 417/427 duplex frequeny pair. Around 20-150 users for that, most hams.

If you want to do HAM tetr, buy a used Motorola (as you can pirate th CPS and buy a cheap programming cable) or Sepura, on Sepura side I'd suggest STP8240, cheap, has SMA as antenna connector, is supported by RadioManager 1.8, which can be pirated and programming cables are available or easily made from the portable charger cable, IIRC just a 3.3V TTL serial port.

For the price Sepura's are a better deal, if you get one's supported by RadioManager 1.8.

RadioMnager 2.0 is around 150EUR if bought and is locked to a single machine. It does not run in a VM, we tried.

Yeah. Alinco's lower end proucts are rebadged or modified Anytone. Tho Anytone is from the less shit end of chinese manufacturers.


 No.1112

>>1107

>Thankfully DMR won the ham digital voice thing here.

DMR rules new england. Quick count on the repeater directory shows around 70 repeaters most linked to the ARES network or DMR-MARC. If your a repeaterhead and just want to ragchew its the system to get on. The 2M analog repeaters are dead.


 No.1116

>>1112

Fuck it. I'm staying on sideband then.




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

 No.321[Reply]

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?

29 posts and 6 image replies omitted. Click reply to view.
Post last edited at

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

 No.627[Reply]

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

2 posts omitted. Click reply to view.

 No.639

They're probably dead already.


 No.662

telephoto compression nowhere near as close as it look. fucking LID retards


 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.




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

 No.750[Reply]

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

5 posts and 1 image reply omitted. Click reply to view.

 No.958

File: 26a69dba849c94a⋯.gif (822.05 KB, 320x240, 4:3, 5828BA82-4A67-4C2B-B502-1F….gif)

>>802

Fantastic.


 No.1042

File: 5715f5e7935ff1b⋯.jpg (23.73 KB, 306x423, 34:47, article-0-0F13C43300000578….jpg)

Studying for the Aussie Advanced Licence, and I have needs to remember how the callsign allocation is done.

Foundations: VKxFxxx – as already well-aware…

Standards: VKxHxx, VKxLxx, VKxMxx, VKxNxx, VKxPxx, and VKxVxx.

Advanced: almost everything else (except VKxQxx, VKxRxx, and a few other little ranges).

What a mess. At least I was able to make a joke out of it…

"Heavy Ladies Must Not Poledance Vigorously"


 No.1064

File: c5ee9dfc415bc8f⋯.jpg (51.49 KB, 410x668, 205:334, lzebnpl3xiv11.jpg)

stolen from le reddits


 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.




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

 No.1110[Reply]

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.




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

 No.962[Reply]

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

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

 No.989

>>985

or just poor


 No.992

>>989

Ya baofeng is a fine entry level rig, when one is aware about it's short comings.

Had a lovely demo on an licensing course.

Wouxun (cheap, but traditional superhet receiver) next to a UV-5R baofeng (with it's low-if DSP receiver) Both on 433.550MHz

And then keying up with a TETRA handheld on 427MHz. Lovely TDMA of the TETRA transmission made the baofeng give out all kinds of funny noises while the wouxun did not.

The 4x in price does mean something.

That does not mean I don't own any boafengs.

I have two of them.


 No.1036

>>962

You get what you pay for. They're cheap. They're questionably legal. They do very little hand-holding. The software and firmware is garbage. Performance blows and is almost always worse than advertised. They fail in bizarre, counter-intuitive ways, and they fail all the time.

There's a difference between a $15 Chinese handheld, a $250 amateur handheld, and an $8,000 professional handheld. If a $15 radio was good enough, nobody would buy the $5,000 radios.


 No.1094

>>985

baofeng HTs blow the shit out of any name brand handheld I’ve ever used.

Yes on the bench their specs are inferior. But comparing their ability to make a repeater contact they’re equivalent. Yes, it’s possible to get one with a piece of plastic jammed in the mic hole and your xmit audio will suck. But, you can buy three more HTs for the price of an icom microphone. So there’s push and pull.

My last HT was a VX5R that I lost on a night training mission. If I lose my baofeng I’ll just get another one for $40.

I think it’s better to get a cheap HT than to spend years saving for an expensive one. Then you can begin deciding how invested you are in it.


 No.1106

>>1094

I wish.

Any more RF dense enviroment and it shits the bed. Had to change from baofeng back to wouxun because the squelch kept hammering open on any setting when in some parts of town.




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

 No.1098[Reply]

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!"

"What's your mother look like??"

"[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).




File: 1449251026045.jpg (84.96 KB, 471x600, 157:200, shy_dog_by_cajophora.jpg)

 No.578[Reply]

I can't do it! I got my ham ticket. I got my HT. I have a club nearby and they run a net (fat old dudes who put the ham in ham radio).

But I can't speak! I just go real shy. Calling CQ is like freaking me out.

What do? I would prefer HF and try talking to people miles away, but the $$$ of a rig hold me back.

7 posts omitted. Click reply to view.

 No.1034

A "I don't go on air because it's full of fucking retards" whinge.

Last Sunday there was a big Antenna lecture extravaganza about 100 miles away that I'd waited a month to go to, but a few days ago the starter motor in my motorbike exploded. Bugger.

So, I turned on the radio to listen to the local VHF repeater to see if anyone else had plans to attend, so I could beg a lift from them… Instead, I got:

VK2FourWheelDriveOwner: I can'ts upload to youtubes from my smartphones

VK2AdvancedRetiree: Use a computer.

VK2FourWheelDriveOwner: MAHSMARTHPONE!

[30 minutes later]

VK2FourWheelDriveOwner: <…> I'm 20 minutes from my driveway

[later]

VK2FourWheelDriveOwner: I can Echolink from my smartphone

[later]

VK2FourWheelDriveOwner: I'm going through …. <never copied because the retard spent 5 solid minutes to give half a sentence in his Over, repeating himself about 60 times>

[later]

VK2FourWheelDriveOwner: I wants to buy a new smartphone this one don't werk

[later]

VK2FourWheelDriveOwner: cekewcekewcekew <blah> Listening

No fucking way I was going to risk spending ~5 hours in a 4WD with that vegetable if he replied to my request. I stayed home.


 No.1053

You could use a Text-to-speech program.

If anyone asks why you use it, just tell them that you are very shy about your voice.


 No.1054

>>579

>Just say hi. Nothing bad is gonna happen.

Fuck you, Anon. I tried that, and…

…a guy breakered and bitched about someone playing 'silly buggers with the repeater'

…and got into a ragchew with the guy who had attempted to do the QSO with me.

…that went on for about 30 minutes


 No.1075

Fucking hell, pls let this be a joke.


 No.1097

>>1053

>If anyone asks why you use it, just tell them that you are very shy about your voice.

>not telling everyone that asks that you're a robot




File: 891a5a783ef1fab⋯.jpg (104.87 KB, 1080x608, 135:76, y.jpg)

 No.994[Reply]

The Yaesu FT-818

The 8Chan hivemind is sighing at Vertex putting any effort into making a QRP radio for the 21st Century, correct?

- pissweak NiMH internal battery

- no SDRness,

- no 'easy' DSP features like software roofing, instead /still/ requiring that expensive Collins mechanical filter bullshit.

- no USB, either for CAT, or recharging.

I /get/ the belief that superhet radios are Real Radios, but chuck that into the extra-enthusiast market, not as the mainline products of CURRENTYEAR.

10 posts and 1 image reply omitted. Click reply to view.

 No.1059

I'm stoked for the qrp-labs QSX kit. 150usd for a all band, all mode 10W rig with a case as a kit. SDR guts with well designed analog frontend.


 No.1060

File: 8e2f74b062de3ca⋯.png (32.68 KB, 664x355, 664:355, qcx-shipping.png)

>>1059

It'll be interesting to see. I have a friend who wants to be the first kid on the block with one, so I'll see what he ends up getting. Hopefully it won't have the IMD problems the uBITX has..

I've got a QCX on order. Goddamn Turkey, since when??


 No.1062

>>1060

Since Qrp-Labs stopped shipping from Japan.

And regarding QSX, it's a more involved build than uBITX. So I'äd suggest uBITX to someone new to homebrewing.

I have skimmed the construction manual for 40m QSX, as it was the kit build at the 2018 South-African YOTA (I was not there, but I know people who ware).

So there are some of those kits built an on the air. But those are mono band prototype series.

The QSX 10W PA is also available as a separate kit from Qrp-Labs, so I have that coming in.

But i fully expect the QSX to be an excellent rig, if they have not fucked up the software.

Early M0NKA mcHF software had shot dynamic range, a more talented dude did some fixes and casually pulled something like 50dB more dynamic range from the design with software fixes only. QSX has a related MCU to the mcHF so potential for the same capabilities.


 No.1093

>>1038

Usb sucks way more than rj45.

The usb connector was made for a shitty keyboard or mouse you’ll plug in twice. It’s rated for hundreds of insertions. This is still true today even in light of things like thumb drives.

Today the biggest factor in how durable a usb plug is is “when will Verizon send me my next phone?”

Usb connectors are shite for mobile use and unlike serial when there is a tiny dropout, your OS closes file handles and forgets all about the device. When this happens in rs232 you lose a byte or two.


 No.1095

File: ed1206910766db6⋯.png (165.72 KB, 352x284, 88:71, why-doesnt-my-t1-look-like….png)

>>1062

>it's a more involved build than uBITX

I found it not a bad build project.. although it took me like 7-8 attempts to wind that fucking T1 toroid.




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

 No.154[Reply]

Anyone here do any homebrew?

-Mod edit- 2015/11/08

This thread is dedicated to homebrew.

18 posts and 10 image replies omitted. Click reply to view.
Post last edited at

 No.1077

>>828

Shit, I'm happy w/ a 3:1 VSWR. Anything better is icing on the cake. That's a 6dB return loss, perfectly acceptable, to me anyways.


 No.1078

Need more home brew projects. Any ideas? Complaints? Concerns?


 No.1081

File: 08c4dfe19375968⋯.jpg (189.05 KB, 1018x711, 1018:711, 20180922-180604.JPG)

File: a7fc7c8ab09db76⋯.jpg (255.74 KB, 679x689, 679:689, 20180927-125237-magloop.JPG)

Made a magnetic loop (or 'small transmitting loop' has a local Elmer carried-on about..) …and a MSP430-controlled stepper-motor rotator for the butterfly capacitor, controlled through a fibre-optic toslink cable. Controller works great, however the loop won't tune below 16 MHz, argh.


 No.1084

File: b9d383f78091159⋯.jpg (356.3 KB, 1200x706, 600:353, 20181228-230320-wspr-on-a-….jpg)

Tonight's project: WSPR on a Breadboard…

Uses a Nano clone, SJWfruit Si5351 breakout, RTC, a suitable low-pass filter (+ dummy load), and lifting the example from http://blog.marxy.org/2018/12/minimal-wspr-transmit-with-arduino-and.html with a few improvements (LCD countdown, etc.)

The drift on it at the start is nasty (-4), but wsjtx still decodes it.


 No.1085

File: a0b021377816a1e⋯.png (109.76 KB, 1154x661, 1154:661, 20181230-wspr-to-zl.png)

>>1084

Sweet. It gets international with the same power (10mW) to light an LED.




File: 8251a8ce5a10682⋯.png (302.66 KB, 416x363, 416:363, AlphaVirgin.png)

 No.1044[Reply]

Hi there, gonna study up and take HAM test soon but, how do you figure out what to buy first to get started ? seems like there's so many different radios and stuff over whelmed,,,

 No.1074

>>1044

1) Buy a second-hand transceiver. Go to a club meeting and ask around

2) Buy a baofeng UV-5R or baofeng UV-82 and use a repeater

73




File: 12168a3efa6b121⋯.jpg (49.57 KB, 579x661, 579:661, twoway.JPG)

 No.1066[Reply]

I was thinking of using those cheapo two way radio with chirp to create a sorta BBS, yes i know there is hambbs system. but how many people want to buy a $200 to $500 rig and setup a 30ft antenna.

Im more going for ad hoc communications.

one thing im curious about is how does data get sent and read without cross chatter.

say for example you have 4 people on the broadcast talking to each other.(A B C D)

and C types the word HELLO and A types the world HOWDY at the same time

how would design the system to know C and A are speaking seperately so B and D dont see one jumbled mess. HHOHELLWDYO

 No.1067

File: cbe0a6fcc59f6fc⋯.jpg (26.25 KB, 500x500, 1:1, 1290356116806.jpg)

I take it chirp.io is just reinventing the Modem for the Millennial generation?

'Packet radio' is the magic spell to google up how Radio BBS stuff is done.

Basically it's just doing the modem thing with a radio, mostly using old modem standards to do the data to-from audio tones thing, and it can certainly be done by connecting a computer's sound system to a radio (although there needs something to frob the push-to-talk). A lot of the proper-ham radios actually have a data port..

>how does data get sent and read without cross chatter

'collision detection' – if a message comes through scrambled, the recipient won't acknowledge it, so the sender retransmits it after an amount of time. Much the same way other network data protocols (TCP/IP, et.al.) do.

Random links:

http://www.mobilinkd.com/2014/09/11/arduino-kiss-tnc/ (TNC == radio modem)

https://g7vrd.co.uk/ax25-direwolf-linux (AX.25 is the equivalent of TCP/IP)

RTL-SDR (we don't need no steekin radios.. A $5 USB TV Dongle can be the receiver half of the BBS..)


 No.1069

>>1067

not radio, audio. Skip the modulation entirely.

But kinda dumb, as every device with a speaker these days also has a wifi interface.

>>1066

interference works itself out with most digital modulation schemes, because it's the phase relationships within any one signal that carry the data. Two signals in the same channel have a random and varying phase relationship to each other, but within each signal the phase information carrying the data stays intact.


 No.1071

>>1069

Wifi is quite short in range, especially if not line of sight. 2.4GHz is a trashband filled with crap.

Are you confusing PSK with CDMA?

CDMA would allow multiple users on the same frequency, but is non-trivial to do.

Unlike (a)FSK with listen–before-talk.


 No.1072

File: 1617e324a505766⋯.pdf (1.22 MB, Building a Decent RF Netwo….pdf)

>>1069

"not radio, audio. Skip the modulation entirely."

You are modulating the RF carrier of the walkie talkie with the audio provided.

The enclosed pdf should enlighten you on collision detection/ avoidance, including some of the pitfalls.

This should give you a foundation on how to accomplish what you are attempting.

https://www.youtube.com/embed/O0RjctOqUf8?autoplay=1&html5=1&&

Also, digital over walkie talkie might not be legal where you are. Just something to think about.

Edited for brievity.

Post last edited at



File: 0c986cbc86e7c3e⋯.jpeg (10.2 KB, 291x197, 291:197, 1.jpeg)

 No.829[Reply]

>FM radio station

нет

>ATSC broadcast

нет

>slowscan porn

нет

>shit talking

нет

>Advancing skills in the technical and communication phases of the radio art

>Spreading international goodwill

¯\_(ツ)_/¯

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

 No.895

>>890

http://www.ve7kfm.com/happymeal.mp3

I once had a good qso with him. Then there was a flood of abuse directed to him.

https://www.youtube.com/watch?v=BGwwIJ6sQao

http://www.ve7kfm.com/


 No.975

>>845

You may be more interested in pirate radio/tv than ham, honestly. The FCC doesn't really go after pirates on the broadcast bands unless they're causing enough interference to be noticed. Digital TV is so sparse there are gigantic gaps of unused spectrum you can just slip into with a low power signal.

Or you can get a relatively affordable microbroadcast license if you meet a few qualifications. I think the most costly part is acquiring a working EAS receiver.

The point of the ham restrictions is not to eliminate fun, it's to stress the difference between communication and broadcasting. You can have a net every night at the same time. You can transmit a QST every night at the same time. You just can't run a radio/TV show. You can't play shows or music because that's what broadcast stations are for. You can, however, have a formatted net where you show your latest ham-related discoveries to anyone who's checked in and listening/watching. It just has to be two-sided and of a "chit-chat" nature. If it starts to smell like commercial programming then it's not allowed.

WRT the "fun factor


 No.976

sorry, … the "fun factor," some people actually do think it's fun.

I get discouraged when 90% of the communications out there are about gas pain and doctor appointments and arthritis but I have had some truly fascinating conversations that went much deeper than weather and lunch.

I think most people just stick with the format of the old code exams and never try to improvise. "Well, the XYL says dinner is ready so must 73…"


 No.1065

File: 12168a3efa6b121⋯.jpg (49.57 KB, 579x661, 579:661, twoway.JPG)

I thinking of using those cheapo two way radio with chirp to create a sorta BBS, yes i know there is hambbs system. but how many people want to buy a $200 to $500 rig and setup a 30ft antenna.

Im more going for ad hoc communications.

one thing im curious about is how does data get sent and read without cross chatter.

say for example you have 4 people on the broadcast talking to each other.(A B C D)

and C types the word HELLO and A types the world HOWDY at the same time

how would design the system to know C and A are speaking seperately so B and D dont see one jumbled mess. HHOHELLWDYO


 No.1070

>>1065

Listen before talk.

So if there is an ongoing transmission, the modem waits. The APRS system works like this.




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