/diy/ - Do It Yourself

03/31/20 Update from Icom USA:
>We hoped to release the IC-705 in May. Due to the COVID-19 virus and parts production, the IC-705 will be delayed.
>We will do our best to deliver the radio as soon as possible.

>>1804757
UHF or VHF?
I only ask because 5/8th at VHF isn't that mini.

>>1805169
>I've only explored FT8 and am getting a little bored.
Sadly, it has overtaken digital comms. Modes like PSK, Olivia/Contestia, et. al. were used for actual rag chewing or similar exchanges. Like using phone is now. JT65A and JT9 are pretty much dead too. It's hard to find anything but FT8, unless it's a contesting weekend.

>>1805144
>>1805145

I really want to do some APRS at some point. I have two MicroModems from https://unsigned.io (see pic) need to make some cables to hook them up a computer or something. I could even add a BLE/Wifi module for wireless access akin to the Mobilinkd.

>>1805208
I've considered porting FT8 to Fldigi so that you could do keyboard to keyboard for however long you wanted. I know there is JS8Call but AFAIK you still constrained to a time slot.

>>1805136
CQ CQ calling CQ is anyone out there? hello? why don't anyone use HAM radio anymore?

Well, I'm in the mood to buy a HackRF One.
Because:
- rx/tx
- good specs
- Ubuntu compatible

Should I go for the original one, or some El Cheapo Chink Clone™ ?

>inb4 chink clones are shit - they saved up to the last penny
>inb4 the original one is sourced/assembled/tested in China anyway - you pay for the Brand®

Fun facts:
- the best APRS decoder out there is the Direwolf software. APRS decoding done on Arduino-like boards (like the MicroModem) can't do advanced filtering shit because not enough horsepower/program memory. Direwolf authors claim to decode 99% packets while firmware-based ones (like TH-D7, TNC's, MicroModem) will decode at most 60-70%

- you still need a radio, a computer sporting an USB port, and some KISS decoder software. Therefore the best scenario is "let's put to work that old radio at home with Xastir". No GPS needed.

- in case of "mobile" APRS scenario (say, equipping your car/bike/scooter) you will have to power both the radio and some Raspberry-like board, and add in a GPS receiver (or - hard mode - interface with the cellphone's GPS). That may be a bit of a hassle, if compared with a 2nd hand TH-D72/TM-D710. Also, you need to be fluent with Linux, Perl, Gpsd, bluetooth, and other shit. Things get even worse if you plan to put up a Xastir live display.

>>1805220
>>1805310
explain "want to do some APRS"
- transmit your position? let's hope some I-Gate will hear you
- receiving packets to show up some map? let's hope your antenna is high enough to receive some I-Gate echo
- enjoy sending your APRS position while on the go, and have it showing on your home APRS receiver? let's hope you don't live in some urban setting

>>1805313
>- receiving packets to show up some map? let's hope your antenna is high enough to receive some I-Gate echo
Remember packets are sent from the Internet to radio only if the receiving callsign has been heard recently by the I-Gate.

>>1805313
>- transmit your position? let's hope some I-Gate will hear you
If there isn't one locally I could set up a receive only I-Gate, I know that may be best practice but it should work

>-...let's hope your antenna is high enough to receive some I-Gate echo
>- enjoy sending your APRS position while on the go...
I guess you're referring to propagation and distance to an I-Gate. Well if I don't try I'll never find out.

Alright! The Ft-891 is here, and I've been playing around a bit. I think this is officially the nicest thing I own.
I have a 6m halo antenna for the lower end of the band. Going to my parent's to get my good power supply over the weekend.

Gonna be fun.
I wish the Swap meets were still going on, I need to find a tuner and an HF antenna ,but have no idea what I'm looking for online.

>>1805208
Call CQ friend. Wait a bit because it takes a while to switch modes.

>>1805283
Well, because Ham radio is like this:

>HELP! My dad and I are camping and he fell out of a tree and is hurt really bad. Is anyone there? We're in the state park right by the fork of the river. Can anyone hear me? My dad needs help fast!

You're coming in about an 8 over here in West County with a definite trace of ripple modulation. What kind of antenna are you running over there?

>>1805668
Ehh, with how many Hams are also into search and rescue, I bet they would fucking love to help.

>>1805283
I think Ham radio is just like every technology, if you get too into it it is degenerate trash. However, if you have a healthy interest in it, it is positive.

https://www.youtube.com/watch?v=JVYzoYny0rQ

>>1805292
Neither, get a Pluto.

>>1805782
>Pluto
This is a popular setup used by hams for the QO100:
AD Pluto transceiver out 0dBm, ~40dB 2.4GHz amp chain producing about 10W, 80cm offset dish with LNB/LNC (10GHz downlink to 739MHz IF) and integrated patch antenna (pic) for the uplink = line of sight to the 'rest of the world'. Almost all use the SDR-Console from Simon Brown (G4ELI).

>>1805668
Kek. The weather here is nice, barameter reading of 56.8. on your final, over.

>>1805856
Funny how two thirds of the time there's literally no signal on QO-100, even though LEO satellites are always booming with signals with a fraction of the geographical coverage.
I'd say the gear costs too much, but then you see most people on HF using a 2000 dollar radio so I don't know. Maybe anything slightly more complicated than a HT is too hard for most hams.

>>1805900
>no signal on QO-100
like now

https://www.npr.org/2020/04/24/843493304/long-lost-u-s-military-satellite-found-by-amateur-radio-operator

Why my SDR do this shit https://streamable.com/1tt4nx
(loud)

>>1806160
Could just be contrast - there should be a slider to make you happy.
Urban area?

>>1806172
No. The Noise floor rises for no fucking reason, the signal is exactly the same strength, nothing changes yet it cuts out periodically which results in a blarringly loud white noise burst.
>Check the video

>>1806177
Seems like that would be the device's buffer

>>1805998
Bullshit.
This is how it really looks most of the time.
https://imgur.com/a/rh2Q9MN

>>1806160
What's the model? Might be software, power supply circuit, clock generation circuit, defective silicon, cold joints... Who knows.

>>1806160
because you're a nigger

did you check the basics, connections, power source, cold solder, broken caps?

>>1806207
>>1806223
You're just saying that because you have less than a general idea on what could be the issue.

Amateur (or “ham”) Radio operators have at their fingertips the ability to directly contact fascinating people they may never meet who live in distant places they’ll never visit. They do this without any external infrastructure, such as a cell phone network or the Internet, sometimes using simple, inexpensive — often homemade — equipment and antennas. Since the earliest years of wireless communication, these radio experimenters, largely self-taught, developed and refined the means to contact one another without wires connecting them. As a radio amateur, you can meet new friends, win awards, exchange “QSLs” (the ham’s business card), challenge yourself and others in on-the-air competitions, educate yourself about radio technology, contribute to your community, travel, promote international goodwill, and continue the century-old wireless communication tradition. Your station is yours and yours alone, and it’s independent of any other communication network.
Let’s take a closer look

Used VHF or VHF-UHF (or “dual-band”) handheld transceivers often are available for $100 or so, and the entrance of Chinese manufacturers into the ham radio market has resulted in a significant reduction in the price of some types of brand new gear.

Those interested in HF work can get in on the ground floor with a used, but serviceable, transceiver in the $200 to $500 range, and an excellent selection of new transceivers is available in the $500 to $1500 range. “Flea-power” CW (Morse code) transceivers covering single bands sell new for less than $100 in kit form; a new four-band CW transceiver manufactured in China and marketed by a US ham radio manufacturer is available for less than $300.
An HF antenna such as a simple backyard dipole suspended from
available trees is both inexpensive and effective.

>>1806226
Ok retard. Quit crying and go buy a new radio then.

>>1806291
Theres nothing wrong with my radios :^)

moar data

Look upon a Heathkit and despair.

>>1806351
>despair
No, work the world!
Did it come with that alignment tool?

>>1806160
Dropped data, it's probably your USB chipset rather than your SDR but try turning your sample rate down and seeing if it changes anything.

I want to use SDR to transmit on CB

What's the best way to do this?

>>1806456
HackRF, filters, multiple amplifier stages, more filters. You're cheaper just using a physical CB.

>>1806456
>>1806457
11 meters can be reached with an fl2k just fine. You still have to amplify the signal almost as much as you would with a HackRF for a lot less money.
Pro tip: if you don't know what you're doing or have decent tier test gear it's going to be extremely challenging to build a decent amplifier chain that isn't drown out in distortion and parasitic oscillations. Trust me, I've tried.
If you just want transmit with a waterfall then just unlock a regular ham radio or add an rtlsdr+frontend saver (RX/TX switch) to a CB unit.

>>1806466
>11 meters can be reached with an fl2k just fine
Even more filtering required but sure, that's an option.

>>1805856
>line of sight to the 'rest of the world'

according to that 'gpredict' screenshot, it's line of sight to Africa, Europe, India, and various chunks of Brazil, Siberia, China.
No North America, almost no South America.

>>1806471
I don't know about that. The fl2k is capable of 100 Msps, so you should be able to get a fairly smooth 27 MHz sine wave. The generated signal can be cleaned up a bit by modding the power supply circuit to use a linear regulator instead of switched mode too. Your homebrew amp is probably going to create more harmonics than the device itself creates. And unless you're putting out hundreds of watts nobody really cares that much about some harmonics.
Again, the main challenge is avoiding parasitics and distortion (which degrades the signal itself and creates horrible harmonics) because of not having a good scope to analyze the result and tweak the resistor values throughout the chain. At least that's what happens to me when I try to homebrew amps.
It's true that you can get an order of magnitude more power or more out of a HackRF, which should help with preventing parasitics because of the lower gain required.

Well, I changed my mind, actually that'd be 3 samples per cycle so not so smooth. You should use an upconverter to bring up a couple MHz wide baseband signal up to the 27 MHz band, so yeah it's going to require plenty of filtering to get a smooth signal.
The fl2k software claims to somehow get high frequency signals through harmonics but I don't know how that works.
Maybe the HackRF includes a programmable mixer stage so that's going to make your life much easier if that's the case.

>>1806302
cant you just do that with a pc?

>>1806302
Noice.
Agreed, PC software can do better (possibly wasting less watts).
The only hardware deserving to collect dust is broken hardware.

>>1806280
>An HF antenna such as a simple backyard dipole suspended from available trees is both inexpensive and effective.

And that's where ham radio ends.
First, pedantically plan your antenna setup. Then realize the bands and modes you were interested in are basically a no-go.
Then try not to think you spent $13k on a 7851.

>>1806226
nigger

>>1806160
Let's see the full bandwidth. If it is from CD to daylight it is most likely a software issue. If it is band limited it is most likely interference. As things are now we have too little information to go by.

>>1806445
"What are 'bodge' wires?"

>>1806497
>Then try not to think you spent $13k on a 7851.
if you can afford that you can afford a better place to live

>>1806493

You can, but I believe hardware TNCs have some benefits to offer. No software needs to be installed, so you can use it with any computer and a simple terminal program on the fly. There is still support for hardware TNCs with APRS and Winlink clients. They have digipeating, BBS, mailbox, and many modes (if a multimode like the PK-232) all in one package. No separate sound card to interface with, or fiddling with a laptop sound card mic/audio inputs.

For true bursty 9600 baud packet, hardware TNC works best, such as the PK-96 or the up and coming ninotnc for the TARPN project.

BUT there is one thing the hardware PK-232 TNC can do that software can not. Which is true ARQ modes. The PK-232 can do both unproto and ARQ Pactor 1 and AMTOR modes. I do not believe software TNCs are capable of ARQ modes, at least not for Pactor 1.

TNCs also have blinky lights and you can see what is going on for coolness factor

but yes software TNC will do better job at decoding hands down.

>>1806568
Keep your firmware up to date, and the HW will always be more robust than SW.

>>1806280
I'm moving to a small farm, and am hyped to get two 50' masts placed likely on top of a 20' horse arena spanning 108' long workable space. Will do at least a 40m antenna. Going to be one hell of an upgrade from my 20m qrp dipole!

Currently using the tree method and an inverted V setup. Hard to get it up high enough to not be NVIS.

yesterday we had open bands and radio contact with portugal, norway, italy, and the deep east european slav lands.

all on 11m, cb is great.

>>1806583
>cb is great

>>1806583
Here in PA it was dead as a doornail and still is.

>>1806583
It's based, especially SSB

>>1806583
I made a 10M 5K mile contact when everything was shockingly open earlier this month.
Definitely jonesing for another 2-3 days like that

>>1806493
>>1806497
Given that a Z80 is capable of handling the load, a PC would be a massive overkill. Since 8 bit computers use little power I am not sure a PC would waste less watts. ARM tends to be power efficient but again that still is an overkill.

>>1806593
>you're not allowed to have good experiences
>please stop
>please

>>1806613
There's always stations around here. Maybe check your antenna and put it up properly next time?

>>1806618
Older chips are much less efficient though.
It won't draw anywhere near as much power as an actual desktop pc but something like a modern ARM microcontroller would probably use less power than an old Z80 even though it's far more powerful.

>>1806568
>https://www.reddit.com/r/PacketRadioRedux/comments/epshtv/30_dual_speed_usb_kiss_tnc_tarpn_needed_a_9600/
>We're not open source at this time. We'll see where this goes.
I find this disappointing,

>>1806656

I think there are project builds with arduino boards for hardware TNCs. You would still need a PC to interface with it to issue commands for AX.25, or for client programs. At that point you need a PC anyways. Unless it's stand alone as a digipeater or maybe i-gate. raspberry pi would fill all those roles.

>>1806651
Signals are not stations. Please include frequencies so I can try again.

>>1806568
is there anyone out there willing to do ARQ modes?
when there will be enough demand, someone will write a software for it.

>>1806618
sorry to redpill you, but the Z80 alone wastes more energy than a full fledged raspberry pi zero

>>1806672
hardware TNCs were born in the era of 8088 PCs, when having a dedicated hardware was more convenient than letting your desktop PC whirring 24/365.
my home PC is a fanless Core i5, I keep it running 24/365. My only regret: it doesn't have 4-5 MIC ports and a couple audio outputs.

>>1806670
"but not as good as Direwolf." Figure me surprised.
A PIC33 cpu can't do lots of fast Fourier transforms and supplementary filtering.

I'm OK with it being 'closed source' as long as it doesn't mean tricks like planned obsolescence or government tapping, but I guess they've got no reason to do them. Chinks will clone the NinoTNC hardware and software in a matter of hours, tho.

>>1806677
are you retarded?

>>1806689
>sorry to redpill you, but the Z80 alone wastes more energy than a full fledged raspberry pi zero
NMOS uses 44 mA at 5 V for 220 mW. The CMOS version uses "orders of magnitude less":
http://www.verycomputer.com/74_e33c05ab19b7f0b0_1.htm
http://www.cpu-world.com/CPUs/Z80/index.html

RPi zero uses 80 mW or 400 mW when idling but it does not state what it uses when running.
https://www.jeffgeerling.com/blogs/jeff-geerling/raspberry-pi-zero-power

>>1806689

I have tried calling CQ in Amtor and Pactor 1. I've never received a response. A response is required to then initiate ARQ as you probably know.

The only times I've used Pactor 1 ARQ was with a couple BBS boards in the US, and Winlink nodes.

The BBS boards are identical to the 300 baud packet boards, just better connection reliability, but only 1 user at a time. I think they just have different ports with the same software.

Fun fact, AMTOR is compatible with AX.25 style mailboxes like with HF packet or Pactor. Just can't do files.

>>1806689
>will clone the NinoTNC
Yeh, I suspected this may be a reason.

I would pay a little more to have access to the source. Not having the access to the source seems somewhat antithetical to what amateur radio is about.

Absolute newfag here.
How the fuck do I make an antenna that actually works?
I tried just putting a wire in the connector but that is somehow worse then the antenna my sdr came with which is like 1 inch.

>>1806758
you don't. buy a premade one from your local radio person, thatll save you time.

>>1806763
fuck

>>1806758
UHF can be hard to get. Try your known, local stations.bFM, NOAA, etc. to ensure your SDR is g2g.
Then just start making and experimenting.

>>1806789
NOAA uses VHF frequencies in the 162.xxx range.

>>1806789
Is this what it's meant to sound like?
https://files.catbox.moe/1r8pai.wav

>>1806767
and do not buy a cheap chinese one, those can be horribly bad and dangerous.
https://youtu.be/bGlHKfFlbvY

>>1806796
The real Nagoya ones are cheap and work quite well.

>>1806798
cheap and _cheap_ are two separate concepts. if people don't know about antennas theyll also not have a nanovna to see for themselves if their gear works at all.

>>1806758
if you're familiar enough with electronics (theory and practice) there are a lot of easy antenna projects. Say, Moxon antenna. Bazooka antenna. Magloop antenna. Dipole. Tuirnstile. Hentenna.
Also, always have a reference antenna to check for your results. Designing antennas is quite a complex science.

>>1806792

Actualy 137.xxx MHz

>>1806813

currently working:
NOAA 15: 137.62 MHz FM
NOAA 18: 137.9 MHz FM
NOAA 19: 137.1 MHz FM
note: using 38 kHz bandwidth

NOAA 15 flying above Australia just now

>>1806819
NOAA is a United States organization, under the auspices of the National Weather Service. I cannot be 100% certain, but I'd question whether a foreign nation would use the same name as another nation's weather radio service.

>>1806809
Keep in mind that nanovnas are very finicky with HT antennas. They work fantastic with HF, vehicle or base Station antennas though.

>>1806813
Plus the based af yagi. A wood rod and tie welding rod and you have a handy uhf yagi (of vhf if you're not worried about space).

>>1806794
This
https://www.youtube.com/watch?v=JrbVrB1egNI

>>1806792
Shouldn't the antenna still be resonant enough to pull in VHF to assure his SDR settings are good enough?

>>1806844
how do I fix it then?

>>1806846
1. Are you the one with the SDR
2. Are you in the US?
If yes, I had that problem once. I recall it being a software setting issue. Play around - and make sure you're tuned into your local NOAA. If that's not working, try a local FM station.

>>1806847
It sounds the same no matter what settings I change.
I don't live in the US and yes I'm using the antenna that came with my sdr.
I think I remember it sounding better a few months ago when I just got it.

>>1806855
I haven't played with SDR for half a year, but iirc, try playing with the I and Q (filters? seq?) and other things.
Your antenna should be pulling in stations clearly. Find a strong signal from your car radio and play around on the SDR until it comes through - then you're set

>>1806689
Wats the point of the ninotnc if its not as good as direwolf.

>>1805159
lol

>>1806758
A quarter monopole is easy to make if you just want to receive. Grab a piece of coax, strip a quarter wavelength of braid off the end of it so just the center conductor sticks out -> presto. For example around 446 MHz you'd want 300/446/4 = 0.168 m. Like so:

======o--------

>>1807114
Alright I'll try that later today but what is this about >>1806794

>>1807115
Probably 5th harmonic of 89.2 MHz FM getting mixed up into 446 due to intermodulation. FM stations tend to be nuisance, getting a 88-108 MHz notch filter helps. You can build one out of some coils and caps, there should be plenty of schematics online. A band-pass filter might also be an option, centered around 446 MHz.

Once you have your monopole it should mostly only pick up harmonics (892, 1338 etc) and subharmonics (223, 148, 111 etc) of 446. Hence the need for a filter. Next step would be to stick an LNA in there after the filter.

>>1807122
thanks fren, just wanted to make sure there's nothing wrong with my sdr.

>>1807124
np. The reason it sounds distorted is because broadcast FM is wider bandwidth than the narrowband FM typically used for walkie-talkies. So it'll clip like crazy.
I'm off to get the tires on my moped changed, bbl.

'cb radio is dead, stop posting about it!'

>>1807189
i love these spectrum pictures, what kind of scanner makes them?

>>1807199
I think it's websdr

>>1805292
I'm waiting for a chink one with a chink portapack and aluminium enclosure in the mail. Total came out to 75% of the cost of just a legit portapack

>>1807199
Every radio equipment will feature that in a very few years.
Note that in a few years every radio will be an SDR (software-defined radio).

>>1805292
I have a HackRF. You get quite a bit for your money, but the lack of duplex is a bit of a limitation. Of course you can just buy two and have one for TX and the other for RX. Or a LimeSDR.

>>1806792
using VHF to tune your SDR isn't a good idea, at higher frequencies in the UHF it's gonna be pretty far off still.
Using GSM is a good idea since it's like 900mhz.

>>1807240
SDR doesn't mean a waterfall. It just means some of the demodulation is done in software. A tube radio connected to a sound card running FT-8 is technically an SDR.

>>1807296
A 1 MHz carrier gives you 1 PPM with a one second integration time. Just configure your FFT to have a higher resolution.

>>1807296
Not to mention the default calibration should be good enough to get less than about 20 Hz of error anyway, which is good enough for 99% of things.
Yes, even WSPR. WSPR doesn't care a lot about absolute frequency, just about frequency stability, which you can't fix through calibration.

>>1807199
it's a websdr.
we niggas having fun on cb, as usual.

>>1805223
Please do!

>>1807336
>likes this

>>1807110

One advantage I can think of is the inter-connectivity of the TNC between multiple operating systems.

Most critical is a hardware TNC will always have faster tx/rx turnaround time for higher speed data modes. i.e. 9600 baud and up. I don't know of any soundcard interface that comes close to almost instant turnaround for data bursts like a dedicated quality hardware tnc.

>>1807658
So the ninotnc is better then?

>>1807658
Is the actual bottleneck the sound card delay or the vox? Vox could be avoided by using the parallel port or similar. Even audio could be done in real time on a cheap STM32 dev board.
I think the main problem is just that nobody has bothered to make a good open source implementation of packet modes.

>>1807681
>>1807689

Bottleneck is the Vox. I don't know of a solution utilizing a parallel port or equivalent. As you said, Nino is the closest thing you will find to what you are describing.

Problem is most people are not programmers and would not be able to do this themselves. At least I can't nor have the free time to learn to do so. Thus the problem of no one bothering without having some $$ in compensation which is totally fair imo.

>>1807440
>fun on cb
The India Morning Net

>>1807296
I never claimed it would. Anon said NOAA was UHF, I informed him it was VHF.

What's you opinion on this?

I have an HackRF, but without portapack.

Should I buy portapack and attach it to hackrf?

Omelette update?

>>1807876
>hackr fone

>10M WAC
So a 5 band WAC is a meme?

>>1807336
except, the tube radio demodulates to audio (a few kHz) instead of waterfalling a large chunk of 10-20-60 MHz and possibly working many different modes over the same incoming RF data blocks.
There's no point in hardware demodulation. Software can do everything and better.

>>1807973
Noice. But SDR will output a lot of heat as well.

'CB is dead: skip edition'

>>1808561
What other autist did you talk to?

>>1808517
Right, but in the case of FT-8 the decoded chunk of spectrum is way wider than the baseband signal (45Hz IIRC).
I mean, the term SDR itself is pretty vague. How wide is wide enough to be considered an SDR? Is a single USB decoder enough or does it have to use IQ demodulation? You won't get two people who agree. And then there's whether software VFO tuning is required for something to be an SDR.
Also, what the other guy said. Wide band DSP and a screen takes some extra battery juice.

>>1809062
*what you said

>>1808561
poortugal, great britain, hardbass enthusiasts

Is it true the higher bands open more during the summer months? How does that affect the other side of the globe? Will my US butt be able to fill more South American QSLs?

>>1809478
I'm pretty sure it has more to do with that during summer we are farthest away from the sun, and moving the slowest along our orbit. I would assume this has a lot to do with why the ionosphere is more active than in winter. Ergo, even though it's their winter the bands should open up for them too.

>>1809491
I would have guessed, as with physics, there'd be equal and opposite forces; when the summer was more excitable, the winter was less, cancelling out any positive or negative effects!
I can picture the summer conditions almost like an Aurora, an escalator or moving walkway, that propels the signal with ease.
Much appreciated - can't wait for summer :)

Summer and Winter propagation has to do with the tilt of the Earth and not the distance from the Sun. Remember, when it's Summer in one hemisphere, it's Winter in the other.

new mast and cb antenna is up.
self-amalgamating tape just wasn't working so the joints are sealed with denso tape. looks awful, feels disgusting, seals great!

Where can I buy pole masts? All I see are push up poles that seem they are temporary. I want a pole mast that I can take down but be permanent.

>>1809756
Prepare your wallet.
https://www.alumatower.com/towers-telescoping-mast-systems/self-supporting-antenna-towers/

>>1809766
ree not a tower, a cheap pole, I dont need anything fancy

>>1809478
>>1809491
>>1809508
Look, it's simple. Sun exposure means both the lower and higher usable frequencies increase. Which is why 20m is used during the day and 80 durimg the night. Summer means more time of Sun exposure per day.

>>1809782

>>1809756
scaffold pole! it comes with every kind of clamp, pivot and fixing you can imagine, it's weldable in a pinch, it's hot dip galvanised so it lasts 50 years on the seafront.
you can use two sticks of scaffold, a swivel coupler and a parallel coupler to make a tilt-up mast, see >>1809527 , the short pole is anchored to the wall and floor, the long pole's 19' with the pivot point at 5', it goes up pretty easy just by hand. you could fit a boat trailer winch and a pulley and bring it up and down with one finger.

>>1809811
That's why short wave broadcasters have a winter and a summer schedule.
https://en.wikipedia.org/wiki/Radio_propagation
Skywave communication is variable, dependent on conditions in the upper atmosphere; it is most reliable at night and in the winter.
Sporadic-E_propagation
There is no single cause for this mysterious propagation mode and no conclusive theory has yet been formulated as to the origin of Sporadic E.

>>1809811
>>1809833
Well yes, but that doesn't change that during summer we are getting more sunlight for longer due to being at the apoapsis of our orbit. Slower orbit means more sunlight for longer.

What gives? I haven't heard a cricket all week.

>>1809968
Earth's orbit around the Sun is almost circular (eccentricity 0.017). The relative change of its orbital velocity (29..30 km/s) is about 3%. The changing Earth–Sun distance (152e6..147e6 km) results in an _increase_ of about 7% in total insolation at perihelion (Northern winter) relative to aphelion (Northern summer). UV radiation is what activates the ionosphere. The difference is minuscule compared to the effect of the solar cycles. Regarding HF propagation during the current minimum all we can pray for is an optimally disturbed ionosphere with lots of sporadic E events.

Just a PA or also an amplifier?

>>1809062

a receiver is a two-stages machine: first, they collect the RF, then they convert it to the "mode" being used (generally audio). There may be a third stage for a supplementary conversion (say, packet radio)

now, traditional radios have both stages implemented in hardware.
SDR's have the second stage done by software.

Thus an SDR is simpler than a traditional radio in that it doesn't have a hardware 2nd stage; it just ships RF data to some computer, and the computer does the magic.

that means an SDR could ship large chunks of data (say, a wider chunk of the RF spectrum, possibly 50 MHz) letting the computer to decode multiple different channels and modes at once.

You may even have an HT doing it "the SDR way": a receiver collects the data, a small board computer decodes it the way the user expects ("an audio channel at X.YZ mhz FM").

Never forget the first RTL-SDR was sold as a TV receiver. Someone took the time to disassemble the software and found out it just decoded TV data off RF data.

So, an SDR can do literally any mode, existing or yet-to-be-invented, as long as there's enough computing power and enough hardware sampling. If your SDR can collect 1 MHz worth of RF, the software will be able to do any mode requiring 1 MHz or less. Say, you could broadcast TV over the HF using an 8 MHz wide channel

Is there anyone actually out there? Installed a new antenna and I'm picking up tons of digital, but nobody is on voice.

>>1810102
Not really besides old nets

>>1810102
>nobody is on voice
40m band has lots of voice at FN21mh, even the king of 7.2 is on the air.

>>1810098
>it just decoded TV data off RF data
How do you think terrestrial TV works, genius?

Does wifi/wan antenna monitoring software exist? I want to get more into hardware and signal stuff but it's hard to google for this kind of thing and not just get store pages for USB wifi adapters.

I wanna be able to see the traffic that's actually passed by my PC or in the air nearby in general rather than just reading the wiki page for OSI Model over and over.

Also, being a 2-3ghz range antenna as it is, is it usable as a general uhf antenna maybe kinda sorta? it'd be neat to try to receive cb traffic or something

>>1810218
WIFI
Yes. This is the best way to learn. Get a wifi radio that can do promiscuous mode. Start reading here:
https://wiki.wireshark.org/CaptureSetup/WLAN

Re-using wifi hardware for other modes:
No, don't bother. Wifi radios are specialized for wifi. There are other radios such as hackrf and limesdr and sdrplay that can be used for general purposes like this, and they are cheap as fuck and awesome. Watch a yt video about SDRNano / SDRplay and be amazed.

>>1810225
I've been asking this question for like two months and this is the first answer i've gotten that wasn't just "NO FAGGOT READ A FUCKING BOOK [link to some EE textbook or obnoxious "maker" "hacker" rag]" and maybe "wifi is 2.whatever ghz so you will never capture anything else fag"

this wireshark wiki article has been illuminating in its simple and concise explanation of use of a monitor on a wifi adapter and does implicitly state why it doesn't work as a general purpose uhf radio by explaining why it might not work to capture everything around it depending on device drivers and antenna implemenation

for genuine radio shit I'll look into those SDRs or at least keep an eye out at my local pawn and milsurp shops but I'll probably be content with playing with wireshark for a bit

thanks nigga, this really was the first non-shitheaded answer to this question I've gotten, and probably only the second or third non-shitheaded answer I've gotten to any question in the past year

>>1810231
SDRs are so new that you can't find them second hand. The technology has only been around for a few years because computers are only recently fast enough.
Good luck, I'm on the same adventure.

>>1810098
>a receiver is a two-stages machine
Wrong, a modern superhet receiver has lots of stages, SDR or not.
>now, traditional radios have both stages implemented in hardware.
Actually a radio in USB mode has more or less the same hardware than an SDR. Including the ADC in modern DSP radios, or just the speaker in older radios.
>Thus an SDR is simpler than a traditional radio
You haven't ever seen an RTLSDR's block diagram, have you?
>that means an SDR could ship large chunks of data (say, a wider chunk of the RF spectrum, possibly 50 MHz)
How much data does it have to ship to be considered an SDR? What if I implement a WiFi radio in hardware that takes dozens of MHz in and outputs GBs of data per second? The answer is SDR doesn't imply any bandwidth. A microcontroller with a 5 kHz ADC can be an SDR, and a commercial satellite TV receiver hundreds of MHz wide can not be an SDR.
>Someone took the time to disassemble the software and found out it just decoded TV data off RF data.
Actually they reverse engineered the protocol from sniffed USB data when using the dongle in FM reveiver mode. The SDR functionality was advertised in marketing materials for the Realtek chip too.
>So, an SDR can do literally any mode, existing or yet-to-be-invented, as long as there's enough computing power and enough hardware sampling.
There are other constraints, latency, timestamping and frequency stability being the main ones. Which is why things like LTE have been hard to implement in SDR by Osmocom.

>>1810102
Maybe you're listening to local interference (birdies). Not every little noise out there is a digital transmission.

>>1810231
You are asking a retarded question. No, of course you can't use a wifi dongle as a general purpose receiver. Otherwise everyone would be doing it already.
The reality is that probably most wifi dongles are actually SDRs, except the manufacturers don't reveal how to modify the firmware and nobody has bothered to reverse engineer.
The Motorola Calypso based phones can do SDR through firmware hacking, and they're from like 2005. We know that because they're the only phone with a reverse engineered baseband to some extent.
I also checked another TV receiver dongle (not the Rtl based ones) and it uses SDR internally too. But I don't know how to modify the firmware.
Even at least some ADSL modems use SDR hardware, except the RF goes over the wire instead of over an antenna, but the chips have been adapted for ham radio use.

>>1810243
>The technology has only been around for a few years because computers are only recently fast enough.
nani the fuck?
PRC-[whatever] models have been able to plug into laptops for decades. on one of the ships i worked on they had some 80s-ass command line box for controlling their radios. even the rack modems and transceiver front-ends are all digital. how are you defining SDR here?

>>1810294
>You are asking a retarded question.
why is it retarded? from the end user point of view, it's a radio. how was I boneheaded to think that something in software would receive arbitrary signal data and then process it, rather than the wifi adapter encompassing more than one layer of the osi model and handing software fully formed ethernet packets?
especially since you can get network cards and laptops with integrated network adapters that work on other things than wifi, usually 3g/4g or proprietary enterprise WANs, and it stands to reason that you can handle modem responsibilities in general without an external analog modem (see: the gorillion thinkpads out there that still have fuckin telephone jacks)

>Otherwise everyone would be doing it already.
how am I supposed to know whether everyone is doing it already without asking? fuck you. i'm going to bomb a hackerspace

>>1810290
Then why is this hobby so dead? I've scanned for hours and nothing.

>>1810309
Gate keeping is part of the ham community. Don't take it too seriously. Though hams can be somewhat territorial about "their" airwaves and hobby, most are just giving you crap to see if you're a whiny baby or not.

>>1805721
When we had an unusual earthquake in my city a month ago, the local repeater was LIT THE FUCK UP because everyone with a ham license was excited for a real emergency. The city actually activated a ham operator from their list to go to the EOC bunker, so we had a direct line of communication with them and got updates before Twitter and other official feeds. To let people feel useful he had everyone report their callsign/location/how strong they felt it, to help build up the map.

>>1806200
Why did you upload to imgur instead of just posting the picture?

>>1806583
I got someone in South America with the CB in my car, completely stock with a 63" whip. I live in Utah and I barely hear anything on the CB, but I was driving to the east and crossed the Rockies into east CO/Kansas it light the hell up. There was a skip open during the Kansas segment and people from all over the east North America with a handful of South Americas were appearing, shit was awesome.

>>1810326
>Then why is this hobby so dead?
>>1810327
>Gate keeping is part of the ham community.

GEE

I

WONDER

>>1807240
I can't wait for these to come out.

>>1807240
>Note that in a few years every radio will be an SDR (software-defined radio).
they already are. do you think people are running around with crystal sets or something?

>>1810352
Yeah, it's not to most productive way of furthering the hobby but some of these guys have been at it for over half a century. Some hazing of the newbies is to be expected.

>>1805136
are 11 meter band operators allowed here?

>>1810379
No.

>>1810394
why not?

>>1810399
The 1970s were a long time ago.

>>1810402
im actually waiting for NEAR fest so i can find an old vacuum tube cb radio and one of the old handheld cb radios that used crystals to change channels i love old stuff it has its charms

>SDR! SDR! SDR!
i honestly don't get why it's got as much woo around it as 3d printing

realistically what's stopping someone from using basically any scripting or programming language to define some signals and then blasting it via the audio out of a computer to the line in of a transmitter? what's stopping the inverse of this, as in after any RF safety and power concerns just hooking your receiver to your line in and writing it to file for use in some other software?

>>1810412
It exists. It's called digital mode, and it's the most popular way of ham communication right now.

>>1810431
So why are people freaking out about MUH SDR as if it's 3d printing guns?

>>1810443
It's the only thing that isn't 1960 boomer tech right now.

I think there's some magical age that as a ham, you suddenly look down your nose at any new technology. It's the same time you wish those damn kids would stay off your lawn.

>>1810443
the 'freakout' is viral marketing, trying to get you excited for shit you don't need.

>>1810412
>>1810431
>>1810443
are there any SDR dongles that TX too?

>>1810465
No. Super spurgs will argue there are some for $3-500+ that tx 5 watts, which is nothing.

>>1810476
couldnt you put that into an amp? I have a shitty SDR but what the hells the point of it if i cant tx? make an autistic websdr site?

>>1810483
>couldnt you put that into an amp?
couldn't you put your normal PC audio output into an amp?

>>1810488
ding ding. RIP IC-705.

>>1810488
NO ANON THATS NOT THE SAME

NOOOOOO!!! MY HECKIN SDRINOS!!!!!

>>1810488
Are you the same guy who thinks plugging an antenna directly into an onboard PC sound card would make it Tx?

>>1810488
oh shit nigga what are you doing

>>1810488

>>1810590
no

>make it tx
why not just type "transmit" if you're willing to spell out "you", "plugging", "antenna", "onboard", "sound card", and "it"?

>>1810326
Where do you live? VHF only goes out a couple of miles.
You need something capable of receiving HF and a good antenna. Don't bother with the direct sampling mode, it's shit. Or receive satellites, but that's more advanced stuff and at a minimum you'll have to go outside,

>>1810309
>how am I supposed to know whether everyone is doing it already without asking?
I don't know, if you researched the topic you'd see everyone was using a specific model of TV dongle because it's the only cheap device that can do it.

>>1810338
I'm banned from posting pics.

>>1810360
Entry level rigs are still the old analog superhet design.

>>1810378
Most hams want to feel special. More people = less feeling special.
Also HF bands are already pretty congested, at least during weekends and especially during contests.

>>1810412
An audio card is only like 20 kHz wide.
SDR allows you to do cool stuff like using a radio as a spectrum analyzer, recording a whole band at once, TDoA, seeing CW CQ calls on the screen as they are made, Websdrs, reverse beacon network, etc.

40 m open to vk since 10utc
vk1icw
vk4xac
yd5lcz
vk3nsc
vk3mcl
vk4la
vk2sr chris still calling

Can I make a radio emisor with a normal radio if I put some amplification? There must be a way

>>1810861
It would be easier to leave the normal radio alone and build a normal transmitter.

>>1810861
If you can find the LO from a digital readout PLL radio you can feed that to an amp to make a CW radio. The problem is the amplification chain is very hard to design anyway. So you're better off just getting a kit unless you're experienced with RF design.
I'm getting there after countless hours of playing with Multisim and trying to implement in real life what I design in the sim. But practice is often very different from theory.

Another thing is that the lack of decent test gear and a good stock of components makes everything 10 times harder.
You might need hundreds of dollars to design and experiment with something that will end up using 10 dollars worth of parts in its final form.

cq contest

Should I study for my Extra or learn cw?
I'm a General that memorized the tests and only do FT8 and have outgrown that.

If I blast too much power into an RTL-SDR, which will fry first - the dongle, or the computer?

>>1811002
Anon, how are you feeding the dongle power?

>>1811002
The dongle for sure. Next the USB port will go bad. Then the rest of the computer.

>>1810644
Because I "can" and "choose" to do so.

>>1810776
>>1810352
>>1810309
>>1811002

>>1810767
everyone uses makerbots for 3d printing; it doesn't mean that the makerbot is the ONLY way to 3d print something, and that 3d printing is the ONLY way to manufacture a part.

>>1810776
>Also HF bands are already pretty congested,
When it's slow on my ship and there's nothing to do, I play with our HF receivers and see if there's anything going on.

Literally the ONLY things I've ever been able to get are news radio and international time stations

>>1810326
>>1810764
If you live anywhere near water then VHF should be constantly lit up with people making passing arrangements and sharing spaghetti recipes over ch 16 and you can shitpost on the harbour nets to your heart's content

>>1811075
>When it's slow on my ship and there's nothing to do, I play with our HF receivers and see if there's anything going on.
Marine HF bands are different to amateur HF bands.

>>1811077
Our receivers can go to any arbitrary frequency in any mode between 1 and 20 mhz. It's not some USB dongle piece of shit

>>1811088
That's unpossible, assface.

>>1811111
it's a big rack unit with a multicoupler that goes out at up to 1000w. it's a fucking ship's HF suite lmao not a baofeng handheld

>>1811111
kek checked
>>1811113
Nice, show us some pics.
Does it have a tuning unit? How does it handle the SWR?
Weird that you can't hear people on 40 and 80 m though. there are people talking literally all the time in the states and in Europe. But maybe not in the middle of the Atlantic I guess.

>>1811147
>Nice, show us some pics.
no cameras allowed in the space also lmao going to work just to take photos of things in the middle of coronameme when I can stay home shitposting

>teh rest
I don't know fucking anything about radio other than hitting buttons lmao because getting info out of people is like pulling teeth and looking it up gets me shit I need to be an EE graduate to understand

>40 and 80
I just said it only goes to 20. do you mean 4 and 8?

>>1811151
>no cameras allowed in the space
Why? Pirates? What sensitive stuff is there on the bridge? (I assume)
>I just said it only goes to 20. do you mean 4 and 8?
3.5 MHz = 80 meters
7 MHz = 40 meters

>>1810327
I have never met a ham that gate keeps

All the guys in my area are just old dudes talking about whatever pops up, there's one kid that last Christmas really wanted a power supply, thought it was funny, he kept going on and on about how he knew santa wasn't real, that he was just pretended for his little sister.

>>1811164
have you read this very thread

>>1811155
>on the bridge?
lol

like I said it's not some baofeng handheld, it's an entire rack. four of them actually. they're each about the size of an average web server rack. there's a dedicated communications room. it's a warship! a very small one, but one nonetheless

>3.5 MHz = 80 meters
>7 MHz = 40 meters
ah ok I see. I thought you meant m as in megs

>>1811175
I suppose you don't remember or can't say the model of the rack so I can look it up?

>>1811168
pic related

>>1811205
It's a bunch of Harris shit, as is the case with any government operation

googing random numbers I remembered found me this which looks like the same model: Harris RF-590A Receiver

https://www.youtube.com/watch?v=M-MIo8eSUbM

it's a set of 4 6ft racks so there's three of these, two exciters, pre/postselectors, some modems for teletype, and they all go to multicouplers going to 35ft whips. there's some other misc equipment in there too but thats the gist of the hf suite, not counting the "teletype terminal" and "teleprinter" and crypto gear and shit. it also shares some space with our uhf suite which is a lot more modern and compact

>>1811226
The antenna tuner is supposed to be the last module before the antenna, but it also might be included in the "pre/post selectors" or in the "exciters".

>>1811253
>The antenna tuner
that's probably in the multicouplers, and the exciters do have "tune" button that makes it make an ungodly racket

I wish I knew more about the system, but like I keep saying, getting info about anything out of anyone is like pulling teeth so i gave up long ago

>>1811256
>and the exciters do have "tune" button that makes it make an ungodly racket
Oh, that's it then.
Are the pre/post selectors interchangeable or specific to each input and output band?

>>1811263
I don't know what you mean but they're hardlined to a specific receiver/exciter and 99.9999% of the time are in remote mode polling the thing it's attached to anyway

>>1811276
Oh so they're controlled by a serial line connected to the radio they're assigned to?

And why do you need more than one antenna anyway? Better reception?

>>1811279
fuck if I know. i've tried asking the fleet management people for diagrams of how shit is connected to what (or at least how it's intended to be) and got nothing. even when they installed new stuff, and I asked the installers to either leave their plans or email me digital copies, they said they would and then just kinda didn't. the only way to get a block diagram of what you have in a comms room is either brute forcing thing by fake troubleshooting, or literal espionage

>>1811280
two transmitters, two antennas, that's what I'm told. and redundancy ofc, always two of everything because apparently we live in the age of sail where individual bits of ships get shot off and not the whole thing is instantly scrapped by an Exocet

>>1811285
So the purpose of the multicoupler is to share an antenna between the transmitter and receiver?

>>1811291
am I being coaxed into a snafu? what is this

>>1811294
I just think it's interesting because that's very different to how a ham radio station is structured yet they have more or less the same purpose. Hams can use up to 1.5 kW and many indeed do.
The way ham stations typically work is radio->amplifier->antenna tuner. I guess the fact that hams aren't going to TX outside the ham bands simplifies the system a little since you don't need tunable filters. Also the fact that in your environment everything is named differently (exciter/transmitter, filter/pre-post selector, multicoupler/???, etc).

>>1811310
I believe the difference is
>exciter
it's not The Transmitter because The Transmitter is the actual post-amp output. i guess
>multicoupler
a big gaggle of things is hooked up to 2 antennas, and the couplers handle the totally-not-multiplexing that's happening. like, we have three receiver sets and two transmit sets, and the transmitters and receivers don't have to be tuned to the same frequency.

but anyway yes that's the point of the multicouplers, to allow receiving and transmitting on the same antenna at different frequencies. I think

>>1811315
>but anyway yes that's the point of the multicouplers, to allow receiving and transmitting on the same antenna at different frequencies. I think
Yeah that's a good point, how can the transmitters be hooked up to the same antenna the receivers are without burning up? Sounds like the transmitters tell either the receiver or the multicoupler (which would be a splitter/combiner in ham parlance) to disconnect the receiver whenever the antenna is being used for transmit (this happens on ham radios internally too). Or maybe one antenna is used for transmit and the other for receive in a full duplex configuration (but I find this unlikely as the interference between both would still be too much to receive anything even with filtering and possibly dangerous to the receivers).

>>1810412
"blasting audio" has some serious limits (usually 48 khz bandwidth, using a noisy circuitry, etc) and it has already been done back in the day (the Zx Spectrum in 1983 was able to encode/decode RTTY without using external hardware, with a 1-bit output; Commodore 64 guys are still raging about it today because their "Graphics, Speed and Sound" machine was basically a braindamaged dumpster fire).

The whole Le Nerd Brouhaha around 3d printing, and the steep learning curve of 3D design/slicing, made it seem like useless wooing. Yet it has a number of good applications, if you can actually design 3D objects.
Same with SDR. If you have some knowledgne and you aren't the usual fag "buy some magic, then expect magic to magically happen", you can make really cool stuff (spreadspectrum, freqhopping, advanced filtering, etc). GnuRadio is your friend. Warning: steep learning curve ahead. Today the only reason to buy a traditional radio is chitchatting (or bragging about a DX) like on the CB but on longer distances.

>>1810465
yes. the above mentioned pluto and hackrf one

>>1810764
VHF goes up to the International Space Station, as long as it's in line of sight.

>>1811323
you're coaxing me into a snafu arent you? i already admitted i dont know shit. why are you trying to embarrass me further

>>1811343
>VHF goes up to the International Space Station, as long as it's in line of sight.
What's it like to have aspergers?

>>1811352
Just be thankful uncle sam is paying you the big bucks to occasionally punch in a few numbers into a radio

>>1811363
I am, it owns and I recommend it to my friends whenever they complain about their jobs

Made my first contacts on the FT-891. All in the SW USA. I'm running an 40m dipole pretty close to the ground, and have a hill blocking me to the east and North. But it's the best I can do in my rental.
I worked the 7QP contest a bit. I see the appeal to some extent but really with it was more than just HI, BYE, 73!
Would be really cool if there was a new award like Ragchew All States. To encourage people to have more meaningful contact.

>>1811596
>Ragchew All States
Great idea. Petition the ARRL?

>>1811343
>pluto and hackrf one
and this

Thoughts on Ham Radio Deluxe? Any reliable cracked editions?

>>1811772
like nigga just use a notepad

>>1811777
checked - but I want to send CW but don't know CW yet

Any idea if they're still doing licensing tests in the U.S.?

>>1811887
I'm a VE. Any others want to make some banks video chatting?

>>1811908
#2 reporting in

My antenna is resonate on 160, 30, 20, 15, 12, 10, and 6 without an external tuner.
I took the tuner out to shorten the connection and am only using the ic-7300 internal tuner - why do I feel dirty?

>>1811992
It's probably the virus.
Just disinfect your brain.

Shopping for portable receivers on ebay is comfy as hell; looking forward to getting something designed in the 80s.

>>1812224
Well, it's early 90s, but I have one and it's kinda nice.
Sangean ATS-818 /Realistic DX-390

>>1812229
I had a PL-660 but the PCB ate shit when a battery leaked so now I'm shopping and looking for something older and more baller. I love having knobs and flippy bits and lights and shit all over.

>>1812235
If I can ever fond one of these,I'm grabbing it.

>>1811908
>>1811916

Is it worth it at all to become a VE as just a general?

Why is HAM so gatekept, they should have allowed online testing ten plus years ago. Instead now we got video testing which is stupid, why are we so worried about people cheating on a test for a dying hobby?
http://www.arrl.org/news/view/fcc-providing-flexibility-to-volunteer-examiners-in-developing-remote-testing-methods

>>1812306
It's free and you get a card. All you can do is monitor tech tests, but there's no downside.

>>1812414
>Why is HAM so gatekept,
There is an exam, hardly an insurmountable hurdle. Even children can and do pass.
>they should have allowed online testing ten plus years ago.
That I can agree to. It also indicates the cultural difference between analogue RF tech vs. digital tech.
Instead now we got video testing which is stupid, why are we so worried about people cheating on a test for a dying hobby?
As the FAQ notes there can be serious consequences, ranging from unintentional jamming of important bands to killing yourself with the high power. I got fried once because the maintenance guys had failed to do their job, I survived because I followed routines and took all due precautions. It was still excruciatingly painful.

I'm really itching to take the test. I take a practice test every couple days, score an occasional 33 or 34, but usually a 35.
Just seems odd that a group touted for being all about emergency preparedness was completely unprepared for this emergency. The FCC is the the part of this hobby that is dying.

>>1811366
Kill yourself.

>>1805136
are you podcasting thats neat

when do u stream

>>1812495
The amateur radio transceivers you can buy off the shelf can only TX on the ham bands with a 15 KHz wide slice of spectrum in the case of FM . You'd have to go out of your way to physically modify the circuit to unlock the frequencies to jam a public service band, at which point you probably know you aren't allowed to TX on certain frequencies.
>As the FAQ notes there can be serious consequences, ranging from unintentional jamming of important bands
>to killing yourself with the high power
The output from a 100 watt radio will not kill you. It will just give you a skin burn if you touch the antenna while transmitting. Touching the output from a power amp will give you some bad burns, but so can boiling oil when making fries, or you can get your hand chopped off with a table saw.
And not everybody does 100 watts, some do QRP where the danger of RF burns is much less.
>I got fried once because the maintenance guys had failed to do their job, I survived because I followed routines and took all due precautions. It was still excruciatingly painful.
What maintenance guys? Sounds like you're talking about something other than ham radio.

>>1811916
>>1811908
>>1811887
brb studying for general.

>>1812580
General seems like it's some real work. Technician is super simple. I have a background in electronics and have been fooling around with radio for years, but even so, it's a pretty basic test.

>>1812582
There's a huge overlap in material. Just memorize the General and you'll pass both.
Tech is only worthwhile for glorified FRS radio.

>>1812588
I have 2m and 70cm equipment, but can only receive on other bands. Technician is a good starting point. There's a lot of local, active repeaters.

>>1812589
It's more efficient to knock it out now
>Spend X hours studying General, get Tech and General
Or
>Spend X hours studying Tech, get Tech, then spend X hours studying General, get General

>>1812594
It's a fair point, but I have no way to use a general ticket at this point. When the 2020 shit storm settles down, I'll resume house hunting and at that time make the decision on taking the next step and get some serious gear.

>>1812596
https://hamstudy.org/sessions/5eafac126ab64b0013c48065/1

>>1807973
Omelette Bro walks amongst us still. He's very upset about the cold weather and not being able to get flowers from the garden centers.

>>1812607
Flowers and gardening shit can't be sold?? I haven't been out in 2-3 months besides to get beer
>>1812596
>>1812580
>>1811887
>>1811908
Here's an online ham test. $5
>>1812601

>>1812617
In our state you couldn't get them until last Friday. The gardening supply ban has been lifted and I think Omelette Bro is probably gardening now,

>>1812623
>The gardening supply ban

>>1812632
Big Gretch banned hardware stores from selling carpeting, flooring, paint, seeds, flowers and other things like that (but I could buy Danish oil and lumber no problem). The ban on flowers is now lifted but I still can't retile the kitchen.

>>1812632
The way I explain it to people is some governors declared buying seeds or seedlings to grow food as "non-essential", yet Amazon was still offering 2 day delivery on dildos.

>>1812623
How stupid. I would have pictured omellette bro would be all over growing his own from seed.
>>1812637
Well said - and given the beer flu allegedly can live on surfaces for 3 days and the Amazon warehouses are a cesspool of disease ...

>>1812640
I handle my packages with gloves and take them in the garage for sterilization and quarantine.

>>1812643
Everyone should handle your package wearing gloves. And I agree - it needs to be sterilized.

>>1812495
>Serious consequences
If you wanted to mess with the bands you can buy all that stuff off the shelf no license required.

>>1812557
>What maintenance guys? Sounds like you're talking about something other than ham radio.
I was a Morse code operator in the military, using HF sets. The principles are of course very similar to ham radios, though simpler and sturdier. There were people at the depot that did maintenance and someone failed to attach the grounding correctly, which I painfully discovered.

This problem is of course not limited to military kit.

>>1812808
No bully, but how old are you? When did they phase out CW in the military?

>>1812808
Yeah, high SWR or bad grounding can get RF on the case of the radio.

Hey, grandpa. I miss you.

>>1812818
they haven't

So what is the average life expectancy of an amateur radio operator now that we know that 3/4/5G causes cancer?

>https://www.nih.gov/news-events/news-releases/high-exposure-radiofrequency-radiation-linked-tumor-activity-male-rats

>>1813099
Must be pretty good knowing all those old elmers out there. Maybe longwave radio is good for you.

>>1812818
>No bully, but how old are you?
To avoid doxxing, let's just say 50+
>When did they phase out CW in the military?
Depends where in the world. In much of the West, the armies dropped it about 40 years ago, navies still use it. In the east Morse is still used. Pilots (air forces and also civilians) still need to know since radio beacons transmit Morse code, though slowly.

>>1813099
>So what is the average life expectancy of an amateur radio operator
Nearly all I know are ex military guys and life expectancy and quality of life is really good. At the time we agreed many of us military Morse code operators were a little peculiar, for lack of better word. In hindsight I'd say quite a few had Asperger's, and that included some of the higher officers. You would not believe the crazy stuff we did. And we even got away with it.

>>1805136
Where do I learn how telecommunication technologies work? How do I learn how jammers work (why do they work, surely they shouldn't)? My curiosity is insatiable, I want to know everything, EVERYTHING, about telecom.

Teach me!

>>1813119
Read the ham FAQ? It is a start.
Read the Feynman lectures on Physics, especially the parts of electromagnetism. You will need a bit of maths to understand Maxwell's Equations.
Read Horowitz and Hill The Art of Electronics, it is more or less the standard work in electronics.
Get the ARRL books, especially the one on antenna theory.

As for jammers, in the simplest form they just overwhelm the receivers. The more advanced ones manipulate the data, see spoofing. The /cyb/ FAQ has some information on electronic warfare (EW). All the basic info is available, the finesse is classified.

library wifi is literally shaking rn

>>1813145
epic free wifi inbound

>>1813145
>>1813147
What is this anon?

>>1813153
it's a proxyham


just kidding fcc please don't rape me
it's just a parabolic wifi antenna and a range extender that i cut open with a saw and put external antenna jacks on
Aim it at whatever target you want and it re-broadcasts that wifi inside your house.

>>1813155
That's fucking neat

>>1813157
It's a birthday present for my mom since she uses satellite internet and it's like 10kbps download speed and it has 4gb download caps per month, while costing like 100 a month.
This should pull wifi from the local library which is around 600 feet away and re-broadcast it inside her house.
Also, I've been thinking of making a GMRS repeater but i'll save that for next thread, i'm not experienced with this kinda stuff and I need some people to give input.

How about some ham news?
>Coronavirus: How amateur radio is connecting people during lockdown
https://www.bbc.com/news/uk-england-52442553
>Amateur radio use in the UK has seen a "significant" rise during the coronavirus lockdown as people seek new ways of staying connected. The national body that represents users - the Radio Society of Great Britain (RSGB) - has said many people who formerly enjoyed the hobby are also returning to it.

>Anne-Marie Rowland has been running twice-weekly meetings to help keep people in contact.
>The 11-year-old from Leedstown near Hayle in Cornwall, who has held a licence for about a year, set up the transmissions with the Cornish Amateur Radio Club to help keep people in contact during lockdown.

How do I calculate the hanging height of a horizontal (or inverted-V) 11m dipol for skipping skywaves? So, how do I get the angle in relation to the height and how do I get the distance I can go related to the angle? Also, how many skips can I go? The less the better I guess.

>>1813128
Dont' spoon feed the troll, please.

>>1813206
Skip is, mostly, dependent on the current atmospheric conditions.

>>1813115
theres old guys because old people get into radio when theyre old.

>>1813099
>2018 peer review of a 1997 of pre-GSM cell study
guys, 8-track might kill us, better stop using it

>>1813161
cool
give RSSI's when set up pls

>>1813119
look up Crystal Sets to Sideband, its a free book that is a wonderful intro into everything you are looking for

>>1810095
That is a pre-amplifier. Place it close to your antenna. It's used when your RX'er is deaf, or to add some gain to a signal before shooting it down a long coax.

TL;DR It's a RX pre-amplifier. (not a PA or amplifier without getting in to autistic semantics).

>>1813287
>pre-GSM
Those were the good times, the towers were far apart and we still had great signal. If we had as many towers then as we do now you would have had signal anywhere in the US, even the boonies.

>>1813335
Gotta have that data speed and throughput. At some point it will be cheaper to just string wire between the towers, since every generation the towers need to be closer.

>>1813326
>That is a pre-amplifier.
That's why the huge heat sink.

>>1813145
>>1813147
>>1813155
How do those even work? Are they just bidirectional RF amplifiers that amplify one way when no TX is present on the router port, and the other way when it is? Or are they smart and decode and re-broadcast the digital packets themselves?

>>1813373
Probably was an enclosure the manufacturers had on stock or whatever. For amateurish short production run stuff I don't think the extra aluminum is gonna make a difference.

>>1813115
>Must be pretty good knowing all those old elmers out there. Maybe longwave radio is good for you.
Sure. Just make sure not to touch the B+

>>1813326
Much appreciated. I had plugged it in and can attest to the pre-amp function
>>1813373
That massive heat sink is what I was wondering if it was an illegal CB amp in disguise. That and 2 switches. I don't have a dummy load - otherwise I'd quit being lazy and just test it out and see.
>No officer, just a 'pre' amp.

>>1813408
Nice confabulation.
>>1813421
The ebay line was:
Century Pre Amp Linear Power Amplifier Transmitter Receiver Amplifier CB Radio

>>1813438
well show us the pics of the insides then

>>1813167
Greta Corona

Does anyone know how to achieve a more or less constant resistive impedance (as little reactance as possible) over a range of frequencies on a buffer amplifier stage built using using discrete components?
The objective is to achieve a resistive impedance for the IF output of a diode ring mixer.

Or does a constant impedance not matter and it can be different over the bandwidth as long as it's resistive? Or the opposite, it matters that it's constant but reactance doesn't matter?

>>1813438
I nabbed it from a yard sale along with this filter, CB radio, and odds and ends
>>1813446
May just build a dummy load with the casing from the low pass filter - that might be quicker lol

I just got an SDR. I live in a city with tons of noise and want to listen to HF.
I have a tall house with an attic.

What kind of antenna should I make?

>>1813537
Do you want to listen to people close or far away? Any chance of utilizing something like a tall tree or pole?

>>1813543
My 3 1/2rd story attic is 40' long and about 8' tall and i can get out to a 25' tall tree that's 25' away.

Do some kinds of antennas cancel e fields and only pick up m fields, or something? New to RF and practical applications doubly so.

>>1810288
>Wrong, a modern superhet receiver has lots of stages, SDR or not.

You know how we can tell you are a retard?

>>1813537
two bits of wire to make a horizontal dipole. string it up wherever it'll fit and get a measure of local rf conditions before you spend any money or effort.

Is it worth it to get a 220 radio?

>>1813555
>..only pick up m fields
Yes, search for 'untuned active loop antenna'.

>>1813537
You could make a mag loop and put it in your attic.

>>1813561
Maybe you are the retard and the rest of the world is smart

>>1813537
Maybe it's not the noise and your receiver is just shit

>How you like me now, nigga? Whatchu sayin' bout me?

New Thread
>>1813941
>>1813941
>>1813941

That 22% power amplifier efficiency. I guess these things really aren’t designed for ham radio. Pic related