That’s why learning on mistakes is a thing

If you don’t want to see weirdos you have picked wrong timewasting site

is equation group prestigious enough “brand” to you?

LEDs themselves are quiet but some SMPSs generate RFI. You can find SMPS that is RF quiet, or since LED strips take so little power, you can make a tiny linear power supply for them, linear power supplies don’t have RF problems

Musk believes in a sort of secular mormonism except instead of magic he has money so he tries to eventually, after millenia to spread his progeny over the entire known universe

You can join from voyager app, and the three instances aren’t listed by default, or so it seems at least

Moxon is very slightly shortened 2el yagi. That other thing is effectively weird phased array of two almost halfwave dipoles, and it’s both worse and bigger, and also harder to make because it requires capacitors for gamma match

they’ll just tape 1 in front of display

(Current rabbit hole: Should a HB9CV’s boom be conductive and electrically bonded to its elements?)

Yes it has to be, that’s how you feed its two elements. Boom is at zero electrical potential and forms half of transmission line that goes to gamma matches of both parts of antenna, and you can attach it to perpendicular conductive mast, or extend it for mounting to mast (has to be perpendicular if mast is metal)

Personally, i’d go with 4el yagi if we’re talking portable operation, because boom length is such that you can make it out of plastic tube and hide elements in it when moving around. Or moxon, if size of 4el yagi is prohibitive. Moxon gets you 2db more gain than HB9CV in similar footprint

who is “we”? as of now, there’s still oil being extracted and fertilizer being produced, just a bit less of it. if you live in a western country you don’t have to worry too much about it, except higher prices of food and everything that gets transported. if you’re a subsistence farmer in a place like bangladesh then you’re to some degree fucked

openhamprep explanation is wrong

When you consider a segment of wire, it has some inductance and capacitance in that small segment, and the wider it is, the lower inductance and higher capacitance are. In other words, both X_L and X_C go down as diameter increases. Electric field lines within antenna are mostly perpendicular to wire everywhere except on ends, where they spread in all directions, which means that there’s some residual capacitance there that needs to be charged each cycle. This is called end effect and the wider wire is, the more of it you get. In fact, the same aspect ratio (length/diameter) gets you the same end effect ratio each time, and it’s usually in range of 0.98-0.95. If there’s insulation, then insulation has lower velocity of propagation as it has higher permittivity than air, and it is in place with highest electric field intensity, and this can also shorten necessary wire length a couple %. The more insulation there is, the more shortened antenna becomes. have a calculator: https://www.translatorscafe.com/unit-converter/en-US/calculator/dipole-antenna/

But wait, there’s more. We can think of antenna as a lossy RLC resonator (sort of), where R is Rrad which for halfwave dipole would be 72 ohms, + loss resistance which is smaller, and neither are changing fast with frequency. What is changing faster is X_L and X_C, and the wider wire is, the smaller both of them are (X_L = -X_C at resonance), and this means that you can go further off frequency and still have acceptable SWR, i.e. antenna made with wider wire has more bandwidth, or if we look at it as resonator, lower Q. For HF this means using masts or wire cages instead of single wire, but for VHF this gets more practical

Resistive part of antenna impedance near resonance depends on physical antenna length, and if antenna is shortened, then how it was done, but for the range we’re here it won’t change much. But also it will depend on height above ground, type of soil, antenna geometry and many other things. 72 ohm is in freespace only

you can consider antenna wire as a transmission line, but it will need to include ground as the other side of transmission line, and then impedance is dependent on wire diameter to height over ground ratio. it’s not very useful except when considering very large and currently uncommon types of antennas (beverage antenna and rhombic antenna, both of which are traveling wave antennas). other than that, transmission line interpretation only works when antenna is very close to ground in wavelength terms, and usually it’s way below what you need for radiation to work properly. when it’s way up there, or in free space, there’s another impedance that is specific to wire in free space only and not dependent on length, but it’s not very useful for explanation of anything in antennas

[email protected]

rtl-sdr uses the same chip as dvb-t tuners, but the everything else part is completely different

lol as if they could plan this far forward

cancer is in large part an old people disease, if you avoided dying of cholera you’re more likely to die of something else. also now there’s a lot of people who were exposed to carcinogens decades back, and we got better at treating pr preventing some other common causes of death like stroke or heart disease

that’s no problem at all, systems like that are in use

It’s easier to freeze water than to cool rock borehole

Saudis parked fuckload of money in ai startups

Lithium-iron is about 2x more expensive, there might be different availability and energy use during manufacture is probably higher

Lead-acid batteries work if you don’t care about weight and lithium-iron phosphate if you do