fullsquare

joined 1 year ago
[–] fullsquare@awful.systems 3 points 10 hours ago

I suspect that we’ll see these “rockets” (missiles?) used for ground based air defenses before too long.

there's already a ground based launcher for APKWS and FZ275 is compatible with it too

[–] fullsquare@awful.systems 6 points 11 hours ago* (last edited 10 hours ago)

No not really. APKWS or JDAM are retrofits of old weapons with new guidance package. Belgium has no large stockpile of old unguided weapons so they get to design the entire thing from ground up. The principle is similar, its a laser guided beam riding missile shot from a heli or a jet, but APKWS sensors are on leading edge of winglets and this new thing has sensor in nose like a tiny Stugna. overall drop-in APKWS replacement with 10k manufactured per month target

[–] fullsquare@awful.systems 5 points 15 hours ago* (last edited 14 hours ago)
[–] fullsquare@awful.systems 2 points 17 hours ago

just unroll the cardboard

[–] fullsquare@awful.systems 13 points 17 hours ago (2 children)
[–] fullsquare@awful.systems 1 points 20 hours ago* (last edited 20 hours ago)

you can distill it before use if you are so inclined, but it would take dry ice and somewhat specialized glassware (distillation of ammonia is more common and it would work just about the same way). there is food grade/cosmetics grade (99.99%) dme available. just in order to not deal with it i would use diethyl ether instead, which can be distilled with normal equipment

[–] fullsquare@awful.systems 8 points 21 hours ago

breaking news: fork found in kitchen

[–] fullsquare@awful.systems 11 points 21 hours ago (2 children)

man if there was a common household chemical, like plastifier, that causes psychosis after couple months of use in small segment of population, you would absolutely hear no end of this [1]. but you see, now it's an app, oh we're just throwing hands, can't do anything about it and it's but one of inconveniences that we all have to pay for Progress and Glorious Technocratic Future

[1] i'm thinking here of things like phthalates, bisphenol A, PFOA or paraquat, herbicide linked to increased risk of parkinsons and banned in some countries. their harmful effects need a lot of time to show up and are nowhere as dramatic

[–] fullsquare@awful.systems 8 points 1 day ago

Altman has been claiming chat gpt made him feel dumb since 4.5

perfectly believable tbh

[–] fullsquare@awful.systems 2 points 2 days ago

that mmwave radar would have to be attached to a drone, because their manned aircraft are unbelievably obsolete. it means smaller size meaning low resolution, and as starlink emits pinpointing them would be very easy when active, much easier than any passive sat dish, and starlink is still in use. i've seen some advice on hiding starlink that includes turning off starlink wifi and using wired connection, because irgc is looking for 2.4 ghz signal (from ground?) and not for 11ghz uplink, so they probably dont have a lot of flying ew/radars

[–] fullsquare@awful.systems 7 points 2 days ago (3 children)

there are ways. for example, put a fake hot water barrel on the roof, made from fiberglass or polypropylene or what have you, but not metal, and put dish inside, or in any variety of inconspicuous containers or boxes made from plastic or wood or fabric. some other antennas can be camouflaged as fake chimneys or gutters or water piping or many other things

 

I'm picking up an idea left by Dick KK4OBI, that you can lower impedance of dipole by arbitrary ratio if said dipole is zigzagged or otherwise uniformly contorted in some meandering shape. Side effect is that dipole becomes shorter and needs more wire. While there's data about impedance for fundamental, there's nothing about harmonics which is something that OCFD might be expected to handle well, so guessing that the really important part is aspect ratio of meander, i've made a couple of VHF-scale models with different meander aspect ratios (and many more much smaller sections), and some of data i've been able to collect roughly matches. The thing I'm trying to figure is what aspect ratio should be to cover multiple bands while using OCFD, say 40-20-15m bands, and whether impedances at different frequencies fall at the same rate. Eventually, when i figure this out, i'll try to make a full size 40m fundamental antenna, as I think that i've figured it out in mechanical terms

However during testing it turned out that I have severe common mode current problems, as two 10mm dia split ferrite beads were evidently not enough, so what little i've been able to collect is mostly useless. When I packed up everything I've found 4 Laird 28B beads that should together give 1100 ohms of impedance or so at 100MHz which also happens to be close to lowest frequency in my setup. Is this enough? Feedline is currently about as long as shorter arm of straight dipole at 22,5:77,5 split ratio, should I change it?

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