qjkxbmwvz

joined 10 months ago
[–] qjkxbmwvz@startrek.website 16 points 12 hours ago* (last edited 12 hours ago) (1 children)

Take numbers with a grain of salt, e.g., this link says a 7200RPM 160GB SATA drive from 2004 is $107, or about $0.67/GB, instead of the $5 claimed in post.

[–] qjkxbmwvz@startrek.website 5 points 1 day ago* (last edited 1 day ago)

Not at all in this case though! Or rather, it depends on your perspective.

"Why doesn't electricity leak out the outlet?" is a good question, if you know nothing about electricity.

"Why doesn't electricity leak out the outlet?" is a little stupid, if you know a little about electricity.

"Why doesn't electricity leak out the outlet?" is a great question if you know a bit more about electricity (because it does leak out, it's just that 50/60Hz doesn't couple to freespace well unless you have a colossal antenna).

As to this question, light in moving media: https://preprints.opticaopen.org/articles/preprint/Fizeau_Experiment_Investigating_the_Speed_of_Light_in_Moving_Media/25441108?file=45147313

[–] qjkxbmwvz@startrek.website 87 points 2 days ago (4 children)

It's a matter of perspective and use


high density one place means you can have open space somewhere else, for a given amount of land.

I'd much prefer a few large dense housing complexes, surrounded by green space, than suburban sprawl.

[–] qjkxbmwvz@startrek.website 2 points 2 days ago (1 children)

Sounds like maybe you want acoustic impedance ? Just like optical index mismatch, or electrical impedance mismatch, you get reflections at discontinuities. Neat stuff!

Not exactly sure what you mean by air-water-air "dampening," but my suspicion is that you're referring to sound being reflected at each interface, so the transmission is reduced. Antireflective coating, index matching, impedance matching are all rich topics in physics and electronics!

[–] qjkxbmwvz@startrek.website 8 points 3 days ago (1 children)

50kW class laser.

Another source claims 1um wavelength with individual 1.5kW lasers in a hex pattern


unclear if it's a phased array (would be awesome) or just trained on the same target (source mentions they are "combined using a mirror" so probably the latter).

Sounds like maybe high power YAG?

[–] qjkxbmwvz@startrek.website 8 points 4 days ago (8 children)

I just want a button that rewinds 10-15s, turns on subtitles, and then turns them off when it catches up again. It's a pattern I do manually with some regularity.

I suppose with Jellyfin/OSS, this is something I could implement myself if I was so inclined...

[–] qjkxbmwvz@startrek.website 2 points 4 days ago (1 children)

Hmmm, I'm not sure I understand...

A large explosion every second has units of power, not energy. So to me this is suggesting that the train is putting out power equal to its kinetic energy per second. That's certainly not the case


it implies that the train is powerful enough to accelerate to the speed in 1s, which is definitely not true.

But that's just my interpretation.

[–] qjkxbmwvz@startrek.website 8 points 4 days ago* (last edited 4 days ago) (3 children)

~~I don't think your units make sense


kinetic energy has units of energy, but "kg TNT per second" is power (about 4MW). (I think just remove the "every second" and it's correct?)~~

Edit: parent edited comment.

[–] qjkxbmwvz@startrek.website 3 points 5 days ago

It's maybe not that bad for a "normal" person, but Bill Nye was a real hero to a lot of young folks, be they aspiring STEM types, science enthusiasts, or just curious people. So to see him sell out


abandoning scientific integrity for a quick buck


was pretty disheartening.

[–] qjkxbmwvz@startrek.website 9 points 5 days ago

You can!

Getting it published is another matter though...

[–] qjkxbmwvz@startrek.website 10 points 6 days ago

Immich looks particularly good to me.

It is! Been running it for a few years now and I love it.

The local ML and face detection are awesome, and not too resource intensive


i think it took less than a day to go through maybe 20k+ photos and 1k+ videos, and that was on an N100 NUC (16GB).

Works seamlessly across my iPhone, my android, and desktop.

 

People often complain about San Francisco's public transit


and to be sure, it's not perfect by any means (multiple separate agencies doesn't help). But the historic streetcars are pretty neat!

They're painted with the livery of various historic streetcars from all over the country (and a few international, I think). Best of all, they run alongside the modern fleet


same route, same fare.

 

Noticed a few days ago that Sutro Tower's red blinking lights are now white. Just asked them on their website form, but wondered if anyone else knows the story with this.

Personally, I miss the red ones!

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submitted 9 months ago* (last edited 9 months ago) by qjkxbmwvz@startrek.website to c/amateur_radio@lemmy.radio
 

Howdy!

I got my Technician in early 2000s, and last year finally upgraded to Extra. Looking to set up a very basic shack.

I'm looking for an HF setup, with most of my use probably using digital modes, but would like the ability to use voice.

Current transceiver is on loan from girlfriend's dad, a Ten-Tec Scout 555


50W HF unit with separate modules for each band. One limitation of this is that the modules set the mode, so it's LSB on 40m, making e.g. FT8 not possible (without some hacking of code or perhaps hacking the module).

Antenna is end-fed with an off-the-shelf 49:1. Currently only have 20m half-wave, but have just enough room for a 40m half-wave in the attic, which is the ultimate goal.

For digital modes, it looks like there are sort of 3 classes of radio:

  • "full digital" where the radio has e.g. a USB port and handles audio, transmit, and frequency set.
  • Some computer-control with RS232, but uses computer audio+adapter to transmit.
  • No digital, use adapter to transmit. This is what the current setup uses (and it works great!)

I'm leaning towards a conventional transceiver, e.g., something from ICOM, Kenwood, Yaesu, (or others) rather than an SDR unit. I'd like the ability to go up to 50-100W if possible.

I don't have a hard-and-fast budget; would like to keep it <$1000 if possible; mostly just looking at used transceivers. Something like a Kenwood TS-590 looks pretty amazing and very "plug-and-play" (but pushing up against price). Something like a Yaesu FT-920 looks pretty feature-rich too; and even something more affordable like an ICOM 706 or even a 725 is probably more radio than I need. Or just grab a new 7300 and call it a day!

Anyway...clearly, I don't know exactly what I want, but figured I'd ask folks with more experience if they have any wisdom. Thanks!

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