now that i’m thinking, you can make loop antenna with circular polarization and mesh reflector with closer spacing that would be even more compact and that would have more of one sided donut shaped radiation pattern, which would be probably more suitable for your application, but it’s guaranteed to have different impedance and so would require simulation

wait, do you want to use it at 140-ish MHz? these antennas will be quite sizable no matter what you do. you can make cross-dipole yagi but with loops instead of straight elements to make it a bit more compact. again, one director will be fine, hell you can even skip it too and just use driven element + reflector. take reflector + driven element from there https://www.robkalmeijer.nl/techniek/electronica/radiotechniek/hambladen/qst/1990/01/page24/index.html and first director from there https://www.iw5edi.com/ham-radio/2425/directional-antennas-cubical-quad this will get you antenna looking roughly like 60x60x70cm box, 60x60x40cm for two-element version. you can get away with using ferrite beads instead of these bespoke sleeve baluns, it’s done this way because it’s made for high power. i don’t think you can get much more compact. you will have to resize it for your frequency. closest band is 144MHz

really you can use any calculator for cubical quad yagi like this one https://www.qsl.net/yt1vp/CUBICAL QUAD ANTENNA CALCULATOR.htm, just with this modification that instead of one feed you need two feeds geometrically 90 degrees apart, that are electrically also 90 degrees apart. this means you can use feed system like this one for 435MHz:

just scaled up for your frequency. also replace these sleeve baluns with a couple of ferrite beads and you’re good to go. mechanically, you can make elements from thick copper wire and you can make it all hold up partially on tension of that wire. remember to factor in velocity factors of your cables

wood is fine but make sure to waterproof it if used outside. use as little as practical, performance can change with weather unlike with plastic. no metal fasteners either as this will have weird effects

do you want it to be compact when deployed or compact when stored? you can also make crossed dipole yagi, you probably want it to be rather nondirectional so one director, driven element and reflector would be fine. that antenna is much longer but i think you get the idea https://www.qsl.net/dk7zb/Cross-Yagi/crossyagi.htm you can also make bifiliar helical antenna but this one again gets a bit directional. you can probably make it shorter than these 5 turns and change pitch too to decrease directionality https://secwww.jhuapl.edu/techdigest/content/techdigest/pdf/V12-N01/12-01-Stilwell.pdf you can also make unifilar helical antenna but it needs a big reflector baseplate so it won’t be as compact, it looks like this https://www.ab9il.net/wlan-projects/wifi3A.html

show me a conservative that accepts blame for anything

most powerful payload developed so far

If you don’t live in complete wilderness and especially if you are in repeater range then yes, there’s a lot of use of 2m/70cm. There are even commercial duobanders for this, but you can also make your own

Lots of things change between HF and VHF. Matching methods, baluns, and materials are completely different. You can get away with 70cm band antenna made of 8mm aluminum tube, and it’ll get you some reasonable bandwidth just because of how wide it is, but if you want to scale it up to 20m it’s suddenly over 20cm wide. This is not practical anymore, but you also don’t need bandwidth like this. HF antennas (other than masts) are mostly made of wires and rely on things other than thickness to make them wideband enough. If you want to use monopole, on VHF/UHF you can use metallic roof as a groundplane. On HF you’ll need to use actual ground with network of wires, which is lossy. For dipoles, distance to ground will be many wl long on UHF, and it’ll work mostly like in free space, but on HF this changes impedance, losses and radiation pattern. On HF, polarization is scrambled after reflection from ionosphere, on UHF it just goes through

Now we have excellent space weather so you can make long range contacts on 10m, but don’t expect it to last. More typical HF bands are 20m, 40m and for these space becomes a constraint. Then you have to pick two out of three: small, efficient, broadband

What bands are we talking about (HF or 2m/70cm?)

Solar panels, specifically inverter is likely to generate a lot of noise

You might be semi-comfortably running linux mint cinnamon on these (assuming 4gb ram) with xfce you’re trading clunkiness and ancient looks for lower memory usage

no idea about the usual suspects, wifi, bt, graphics probably will require tinkering as is tradition

how low we’re talking

xubuntu is fine if your box is a potato or if you’re coming from windows vista

i’m here to remind you that for last 20ish years half of the time chemistry nobel goes to biologists, and now they doubled down on ai wankery with giving it to alphafold

older plants matter less specifically because these are less efficient - operating them means more fuel costs per MWh. normally, you can see new flashy plants generating all the time it’s practical, because these are more efficient, have less maintenance downtime etc and when demand grows, progressively less efficient units start generating coming from spinning reserve. the two exceptions are NPPs which are best operated at constant high power because of their neutron physics and renewables that are literal free energy so everything they do is taken in. the only place where you can improve efficiency of NPPs is in turbine, and that probably is pretty well optimized unless turbine is very old, because increasing steam temperature would mean changed conditions in reactor in way that could happen to be out of spec. we have figured out wind power pretty well, and perovskites aren’t a thing, and won’t be a thing until they become more durable, which they won’t. in all cases, upgrades would have to make sense both economically and/or in emission costs. this includes CHP and laying municipal heating grids, and good luck with that with how dysfunctional american local govts are (where probably biggest emission gains from CHP could be made)

you can redo this for other types of thermal powerplants and come to the same conclusion. if you say that saltman&co and his assemblage of lying machines can outsmart thousands of turbine engineers, you might be a shill for making other people believe that or a moron for believing that yourself

all these private jets

CCGTs have efficiencies in the range of 60%-ish percent. bringing it up to 85% would mean that now these run almost at carnot efficiency taking adiabatic flame temperature of methane burning in air as upper and practical temperatures of heatsink (60C) as lower. this is not happening, because other cycles with lower efficiencies are used in practice

if you want to improve efficiency of power generation, just replace old junk with new kit, or better yet, build nuclear and renewables where efficiency matters less when considering emissions. you know what, damn i do think that lying box burning enough electricity to power a small country (like macedonia) could come up with this

not gonna happen, this would break thermodynamics. he made that up on the spot, he’s full of shit and he knows it

that’s how everyone does this for two years at this point, yes

slightly more refined version is crush switch, that is two thin metal shells in front part of missile. when it hits the target one deforms and makes a contact with the other one. used by, for example, french HOT-2 missile but probably many others considering how simple it is

it better be, shaped charges are probably cheapest part of it (other than chassis)

nice, now ukrainians can inspect ka-52 radar closely

you are part of the problem