/hamradio/ - Electronics

>>990

Perfect!

>>784

Err, having four at that angle tends to bring the impedance to ~50 ohms. But this is lore, not hard fact.

>>784

Also, How far are you getting now?

Who gives a heck about impedance matching anyways!?! go for max power out. As far as I know, you can't have the best radiated signal without a good match anyways!

>>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.

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

>what are you going to do via shortwave?

Shitpost like I've never shitposted before.

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

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?

>Spend 9 months getting licenced, getting hardware sorted, hardware working

>learn the EM waves, learn the oscillators, learn the filters, learn the matching

<…and The only local activity is the 4WD Owners chat

Fucking Amateur Radio taking all the fun out of being a Radio Hobbyist. Nothing kills a hobby faster than other people insisting doing things their way.

I just want to generate radio and see that it works, not get caught in a forced conversation with a cashed-up bogan.

15 years ago, my area had a big ATV and packet scene, and that's been completely erased. :/

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.

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.

>>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

Fucking hell, pls let this be a joke.

>>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

>>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.

>>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.

>>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/

>>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

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…"

>>1065

Listen before talk.

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

>>530

K4PSB @ libertyandlead2.blogspot.ca

N0PE

W6DJL - DX Legend

T!

Mojave Desert, California USA

>>740

Happy B-Day

KI4VVA currently residing in N. Idaho.

>>802

LOL

https://www.jaycar.com.au/9mm-x-100mm-inanimate-ferrite-rod/p/LF1010

(Simpsons reference!)

baofeng UV-5R is a low barrier to entry VHF/UHF. Don't pay more than 25USD shipped. Tho you'll get that 10% chinashit tax.

People are gona say it's shit, but it's 1/4 the price of the next tier.

It's a basic 2m (144MHz) and 70cm (433MHz) FM radio.

Some models also have the 222MHz band, if that's a thing around there.

For general listening and testing, buy a RTL-SDR stick, these are under 10usd shipped from ebay/aliexpress. Keyword are "rtl2832 t820".

Buy a big blue one. rtl-sdr.com also sells their own dongles for double the cheap china stuff and has tons of stuff on what to do with the dongles.

It's a 24-1500MHz receiver that works in all analog modes and many digital one's too. Good learning device for checking out what's on the VHF/UHF and CB bands around you. And for building your own antennas for receiving.

For HF, the world under 30MHz, there are some cheap options these days. Either buy a used 100W all mode for around 200-500usd.

A new Alinco for 600usd.

If that sounds too much and you are not afraid of a little soldering, there's the uBITX from hfsignals.com

3-30MHz, all bands CW/SSB, 10-2W depending on band and mods.

Has an active community and the design is open.

129usd shipped from:

http://www.hfsignals.com/index.php/ubitx/

There are other kits too and the up coming QSX SDR SSB radio from qrp-labs. But the uBITX you can buy right now.

For antennas I'd suggest building your own dipoles to start out with on HF. I think 80m and 40m would be good bets on HF in australia.

If you want a cheap antenna analyzer for checking the home built antennas the <60usd SARK-100 analyzers on ebay and aliexpress are ok. The also connect to a computer via usb for graphical plots and other features.

>>1055

Where in Australia?

There's three levels of proficiency: Foundation, Standard, and Advanced. In Sydney, there's a Foundation/entry-level course run by ARNSW at Dural that's excellent (did myself); and they do it over a weekend, so they don't waste time. There's the potential to Fuck Up Really Badly with radio, and the F-call stage is really about getting you not do that.

Otherwise, try to google who the nearest club is in your area, rock up to one of their meetings, and just ask a random person there who the guy is that can help get a licence.

To give you an idea of what you need to understand at Foundation level, watch the Ron Bertrand RES tutorial and 'practicals': https://www.youtube.com/user/ronwber/videos

There's the "Your Entry Into Amateur Radio" book for about ?$25 that's available from most Clubs, and most Foundation courses will want to have it. (I really should scan mine and do a PDF..)

…and then try to make some mates in the local group who into the kind of stuff you're keen on. That's the hard part. There's a lot of dawkins-memes in Amateur Radio that want to infect a fresh young brain– shit like Contesting, DMR, maintaining a clubhouse for the sake of having a clubhouse, HF frequency 'Nets, or otherwise 'talking' to boring-ass people on repeaters– which really aren't a lot of people's idea of Interesting, but get pressured on as something you should be doing.

>>1056

>So if you are not licensed and want to see what's out there on the bands, buy your own rtl-sdr stick [..]

Alternatively there's sdr.hu for a list of online KiwiSDRs that let you tune the whole HF region. In VK4 there's http://vk4tmz.freeddns.org:8073/ doing 2 metre/VHF as well (I was using this and gpredict to catch the AMSATs downlinks…)

> VK3YE on youtube is one australian ham building stuff.

He's an autistic nerd in shorts, but he's our autistic nerd in shorts… He's more into hacking things up, too.

VK has its own magazine that's often useful when trying to understand stuff (and where it goes..) https://armag.vk6uu.id.au/index.html is an archive of issues >10 years old.

>>1039

>>Tell everyone the 817/818's receive power consumption. It's among the worse around in its category.

>First tell me what figure you're using and how it's measured.

No, you have to go to a website reviewing the FT-817/817 yourself and post it here. What? You don't want to be made to post "Sorry, I was lying and denying facts, because I'm one of those incel flakes who hangs out on 'Dolf worshipping websights."

As it's obvious you need hand-holding, I'll help out a bit: https://www.google.com/search?q=ft+817+receive+power+consumption

>I'm going to need sources on this.

Every USB2 RTL-SDR dongle ever made, fuck.

(This is were you go "hurr they has like 2 bits resolutions")

>>1040

Holy shit you're clueless.

From the very first fucking link:

<…Even though it pulls roughly 300 milliamps when sitting idle on receive, this is certainly less than most any other full-featured HF transceiver that you'll likely find. (Yeah, yeah, I'm sure you can come up with an exception or three, but I did say "most.")…

<…There are also a number of mode/band/option selections that can significantly affect current consumption. Below is a list of various parameters that can affect current consumption…

<…Display backlight: 27 milliamps, regardless of color….

<…Rear antenna: 20 milliamps of additional current is consumed when the rear antenna connector is selected owing to the relay being energized…

<…When squelched, current consumption reduces by between 9 and 11 milliamps, depending on band and mode…

<…Next to the radio just being on, the audio amplifier can be one of the largest factors affecting current consumption, and minimum volume is the best way to reduce this current. Current may be further reduced by using headphones instead of the internal speaker. This current saving can easily average between 10 and 20% when listening on a noisy HF band…

>USB2 RTL-SDR

Yes, because a muntzed-as-fuck over-the-air TV reciever that can be badly hacked into a lousy wide-band receiver when connected to a massive power-hungry computer that it absolutely relies on for all signal processing is a perfectly valid competitor to a compact, high-performance, station-in-a-pouch transceiver.

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.

>>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.

>>932

I have built a few, all are shit.

I'll take a look if I can source that.

Thanks for the suggestion.

>>933

I expect the big part of learning Morse is getting the rhythm down, which a properly balanced key helps with, and a thrown-together switch doesn't.

Note also how the 'British'? keys have a spark-guard, and the American-style ones don't. Apparently the subtle difference in key grip and action is what gives the Yanks RSI and had them invent Bugs and the like…

>>931

Machinist here from /laboratory/; any chance you can post those cad drawings?

Bought one of those chinese "K-4" keys on aliexpress for 45eur shipped.

I hope it's not 100% trash. They are reportely made by the same factory that made the well liked "heavy chinese military keys", but are new production and have shittier fit & finish.

Along with a stiff spring that needs shortening.

A lot of the info about the keys online are about the original 1960 manufacture chinese military keys sold by morse-express, which ware well made.

Oh well, one can hope.

At least I'll have something to feed all those chinese qrp kit's I have built.

Does anyone do FreeDV 700D or 1600?

https://youtu.be/w_urWSSZgwU?t=30

My hypothesis is that those people who only get an entry level baofeng are less invested in the hobby, and are therefore more likely to put it down.

Just some fuel to stoke the flames. :)

I wonder if there is a way to test this hypothesis?

>>984

>>978 claim, not mine.

>>985

or just poor

>>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.

>>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.

What am I look at here?

>>1019

Hyperlinking allows references to other content, providing pointers of a kind to further information. They're followed by clicking the hyperlink with a mouse, or touching its area on the screen.

Exiting stuff for SDR hobbyists.

Can't wait to see what this will result in.

>Hai guise so awesum i'm spoofing GSM!

>lol opensource Stingrays when??

facepalm.bmp

>>1025

At least then there will be proper effort to build protection against them when kids can make 'em for 20usd.

But I don't personally see that as a viable problem.

The current "GSM spoofing" thing for fl2k literally just repeats a prerecorded transmission.

So it looks like a GSM bts, but there is 0% smarts to it and no receiver.