Considering that they think that chatbots are as important as nukes, there is a precedent https://en.wikipedia.org/wiki/816_Nuclear_Military_Plant

No, width is your design parameter. I’ve used 4mm wire because store ran out of 5mm wire, but 3mm would be fine too if you can make it work mechanically. Were it all in air with no plastic, width of both is such that impedances of matching section are close to 300 ohm. Plastic around it lowers impedance and makes wire appear longer. 2m antenna has 220 ohm matching section and it also works. Rectangular connection boxes also work but the ones i could get weren’t as stiff. The way it’s done, bottommost section can be clamped with a regular pipe clamp, it’s harder with a box. Either way 4 or 5mm is not thin on 70cm so impedance of dipole will be probably lower than 5000 ohm, and entire band is covered so it just works

Pick any material you’re comfortable with. Start with 1 wavelength + couple cm of wire, measure out 1/4 and bend it so that 1/4 length point ends up at the bottommost point. Tune by trimming (both arms, lengths of shorter and longer should stay 3:1) and match by moving feedpoint lower or higher (lower is lower impedance). That’s why I’ve made them this way, you can see marks from screw near feedpoint because feedpoint was moved a bit both sides during tuning. By the time trimming gets minimum SWR close to say 420MHz adjust feedpoint to get minimum SWR then alternate between trimming and adjusting feedpoint if necessary. Every mm counts, small trims are better done by filing the wire down instead of cutting it. Plastic needs to stay on during measurement. Keep some 1m of free space (without large metal things) around antenna during measurement

Paging @tasankovasara@sopuli.xyz for logistically efficient antennas

Most of the magnetic flux should be contained in ferrite, and the part that leaks is pointed at the middle of other ferrite so it shouldn’t induce anything. This is fine

exactly, the ferrite only affects common mode current. you can think of coax as being composed of 3 conductors, core, interior of shield and exterior of shield. above some frequency and below frequency where coax starts to work like a waveguide, internal surface and core carry opposite currents (differential mode), and external surface carries common mode current. these can be treated as separate, except at the ends, because of skin effect. but also you can use twisted pair, because differential mode currents cancel out there

that’s just a piece of wire, perhaps some thin steel rope in a heatshrink attached to center conductor and trimmed to length. 1/4 wave at 2m which is fine, 3/4 wave at 70cm which means it’ll radiate most of energy upwards (wasted) when put on a conductive plane. this works because the other half of antenna is low power, handheld radio and operator (coupled by hand capacitively). putting 100W into it would be a bad idea because all that current will travel along the coax down to radio and operator except this time there’s an option of rf burns. for this kind of money, i’ve made two jpoles with extension cables, and the most expensive part was enclosure

i’ll make a post over the weekend about j-pole antennas that i’ve made recently. one of them even looks halfway professional

move fast and break yourself!

Believe it or not, there are bacteria that live on surface of fuels and oxidize them for energy. Sometimes there are antibacterial additives, sometimes they are filtered off, but sometimes these just fall down to the bottom of storage barrel at gas station. This, mixed with rust and a little of water, forms that sludge. They see that because gas station runs out of fuel

This is why i always place all important info in Supplementary Information which is almost always free of charge. except on sciencedirect. fuck them

that could be any of who knows how many untested things he tried over years

“don’t die” - famous last words

e: this is also sorta why clinical trials are a thing, and why so often there’s recommendation to not treat disease at all, and why you leave that call to a professional, not decide on your own. especially when your own education is MBA from BYU

update 2: bluesky people say he also ate rapamycin then stopped; also dried cow thyroid; got some unapproved “anti-aging gene therapy” in honduras; probably among many other unusual things. he won’t be even useful as a case study because deconvoluting all this nonsense would be impossible. maybe as an example

man they really do like reinventing alchemy, did anyone suggested cinnabar yet? i guess him blaming sugar for it might be beginning of new grift

i’ve seen someone made rollup j-pole on basis of fabric strip, with conductive fabric strips sewn on. so you could probably take an actual flag and do the same, because yagi elements need some thickness and flat strips are good enough. this looks a lot like yagi printed on pcb board, except that pcb board is stiff, and you’d need some rods to stretch the fabric. so there already is need to store long sticks. instead, you can make a regular yagi but with elements that can be detached when not in use. i bet somebody made 3d-printable clamps like that

there are commercial antennas available, but you will pay an arm and leg

that’s good, we’re not starting from zero then. take note that some solutions that work for 27mhz band don’t work on vhf/uhf, mostly balun and impedance transformer construction. HF baluns use multiple turns of coax or twisted pair through ferrite, on VHF and up it’s better to use single turns (ferrite beads) or transmission line baluns (folded balun or sleeve balun). it’s also more practical to use some form of transmission line impedance transformers (like quarterwave matching). on vhf and up lumped element tuners are not really a thing, antennas are much smaller so they’re just made to match

The particular antenna I was asking about is something I couldn’t DIY

i’m not familiar, if you could describe it in some more detail that can be probably figured out

for 70 cm, i’ve suggested jpole because it’s compact (long and thin), you can probably package it in 30mm or smaller plastic pipe, haul it around, pull out and mount it with a clamp on top of (not parallel to) metal mast and be good to go. you can have metal mast couple cm below shorting bar of jpole, or even a bit away and parallel to for a short run and it shouldn’t matter. if needed, radiating part can be mounted parallel to metal mast but needs to be a good distance away (halfwave away or more unless you want to tune it in place). with nonconductive mast the only conductor nearby is coax. it would be 50cm-ish long so good for mobile setup. these are fast and cheap, the way i’ve made them the most expensive part was plastic box, can be made and tuned with nanovna in a single evening

groundplane antennas would be even shorter but much bulkier, unless you detach radials or mount them on a kind of swivel mount, and you have to put them in the air, as in, bottom end of radials can’t be too close to ground. mast considerations are pretty much as jpole, as in, the hub can be mounted on top of metal mast but not parallel and right next to it. if folded, 2m version would be about 50cm long, so it’ll probably make sense on 2m and down. you can probably make a 70cm band quarterwave whip attached to magnet so that you can put it on roof of your car, but it won’t be as good because height is might here, and jpole has center of radiation half wave above mounting point just because of the way it’s built. just that little bit of extra height might clear some obstructions. straight dipoles should also work, but they’re T-shaped unless disassembled, and you’ll have to run coax perpendicular to dipole for some length to avoid common mode current problems -> not as simple mechanically, fine for horizontal not so much for vertical

you could also make a small (5-7 el? depends on how long do you want it) 70cm band yagi and store it on top of your radio box, but you’ll need to put it on a mast then rotate it, or hold it in your hand, preferably standing on a hill or something when in use. stiff jpole would be probably fine for 70cm, 2m if you can accommodate the length, lower than that, 2m to probably down to 6m or 10m, rollup jpoles should work okay as long as you have a way to deploy them. below that it’s probably mast + some kind of halfwave dipole territory (efhw? doublet? series of center fed dipoles? ocfd? some type of vertical? you decide)

You have to keep in mind to not exceed coax bending radius. Solid insulator (as in not foam) coax works better. Somebody has measured them http://www.karinya.net/g3txq/chokes/

I’ve seen people using twisted pair of enameled wire (50 ohm) instead, or a pair of insulated twisted wires connected in parallel (each is 100 ohm impedance) this allows for much tighter turns. This works only for HF, for VHF and up there are alternatives and multiple turns don’t make sense, it’s better to use ferrite beads

antennas are on the more diy-able end of this activity, no need to buy them, make your own. firestik is a cb band (27mhz) antenna so you can’t use it anyway for this (your radio can’t transmit there either). you’ll need a way to measure your antenna, which means you need a tool like nanoVNA. for 70cm band, j-pole antenna will be easy to make and compact (50cm ish long) and would be either stiff (made from small diameter copper or aluminum pipe/wire) or elastic (so that it can be rolled up). if the former, put it all in a pvc water pipe sealed on both ends, with coax output going through a cable choke, or put the bottom section (from feedpoint to shorting bar) in some kind of plastic box, with wires also going through cable chokes. note that when tuning, pipe needs to be on antenna, because enclosure will shift resonant frequency down. you can mount the enclosure with metal clamp to something as long as clamp is below the shorting bar at the bottom. if latter, use twin lead for the parallel line section, or make your own because it can be hard to get (like this) aim for 300-450 ohm impedance. then you can roll up this antenna when not used and suspend it from a fishing rod (wood or fiberglass only) or from string attached to tree or something when you need to use it. in either case, do not connect shorting bar to coax shield and do put a ferrite bead or two on coax. do not deploy antenna directly next to conductive surface or rod. do not deploy antennas next to power lines. if you want to use 2m band, you’ll need separate, 3x longer antenna for it. there are slightly more complicated ones that get you both 2m and 70cm. there are many guides about this, but this is one of simplest ways to get it working

that said, you’ve got a pretty capable, heavy and expensive radio here. if you just want to use 70cm, then you can get away with something much smaller and cheaper, you could hold it in your hand. like baofeng, or quansheng if you want to reflash it. 70cm (UHF and VHF in general) allows for contacts within line of sight only; put your antenna on a mast for more range. HF bands have different limitations, but range is not limited in this way (it’s limited in different way). there are many schools of thought on how to make it work best, but general shape of solution is either halfwave-ish long reel of wire (low tens of meters) that needs to be put high in the air, horizontally, either using trees or fiberglass mast as a support, or some kind of conductive mast (or nonconductive mast with wire going up along), about quarterwave long, with wires of similar length strewn on ground. there are many choices and tradeoffs depending on where you intend to transmit from (car? bike? some mobile setup with everything fitting in a backpack? shed in the woods? tent in the desert?), target bands (HF or VHF/UHF or maybe microwaves?) and how are these supposed to be used (CW? phone? digital modes? point to point contacts? through repeater? through satellite? bouncing signal from the moon?)

neither left wing or right wing (right wing (crackpot edition))

like any proper demon, thiel only* uses blood of children

* he’s extremely afraid of dying in general so he might be popping any immortality pill that was sold to him. i heard something about HGH

You can cut open and flatten a bit of wide (1”?) copper pipe to get a piece of copper sheet for grounding, if you can’t get it otherwise

Is there one bulkhead or two, and if one, how will you attach third and fourth cable?

every week of work with biologists brings another “guess we doin circles now” moment. there’s simply so many things that were never measured, measuring them requires knowing what are you doing, proper experimental design and interpretation of results, that are affected by myriad factors and dozens of feedback loops. none of that is in training data of course, and even if it was it would help very little because humans measuring that would make better use of these results first. but don’t worry about that, machine god will learn relativity from three video frames and will make peter thiel immortal right away