• 0 Posts
  • 68 Comments
Joined 2 years ago
cake
Cake day: June 12th, 2023

help-circle




  • Something that should maybe be pointed out about ham radio is that there’s local ham radio (VHF/UHF) and there’s long distance ham radio (HF). People keep mentioning that ham radio can reach long distances, even other continents, and that’s true but that’s the harder, more expensive HF side of ham radio.

    When you get your first ham license, you are limited to VHF/UHF bands and a little slice of the 10 meter HF band that isn’t very useful. Even if it were useful, most radios are either VHF/UHF only ($100-300, $30 for a lower powered handheld radio), HF only ($500 and up), or all bands (well over $1000.)

    It’s hard to talk about range because it always depends on location, but VHF/UHF has a range that should cover your town/city and maybe enough to reach the next town, maybe enough to reach outside the disaster zone, depending on the disaster. VHF/UHF only needs a simple, cheap antenna that you can stick to anything and it’ll just work, more or less.

    HF generally requires big antennas that take a lot of tweaking and/or other expenses to work right.


  • CB radio is very low power and limited range. I had a CB in my Jeep for offroading. It wasn’t an ideal installation or an ideal antenna, but it was basically what most people driving a normal vehicle and not really serious about CB-ing would install.

    It was good enough for the trail where I was 100 yards from friends but going down the interstate listening to trucks, I was basically limited to trucks I could see within a half mile or so.

    With a 2 meter ham radio, the most common band that even beginners can use, and a lot simpler to install than CB, I can talk 20 miles fairly easily, twice that to reach some repeaters in the mountains.




  • Growing up, we had a neighbor in the Air national guard who was a boom operator on KC-135 refuelers, meaning he controlled the boom that comes out the back of the airplane and transfers fuel to other aircraft. The boom operator lays face down on a bench and looks out a window in the back of the plane to control the boom.

    When I learned that they “operate on their belly”, I somehow interpreted that to mean he performed medical operations on people’s bellies.

    It didn’t even make sense to me at the time but I figured there must be some special reason that the operation had to be done while airborne and I was impressed that our neighbor was not only a doctor but an airborne surgeon who specialized in this one belly surgery that couldn’t be done on the ground.










  • I’m sure they’re smarter than me but my novice cryptographer brain doesn’t understand this.

    Isn’t the string of numbers representing each pixel rather limited Aren’t all those sections of the image that have lava lamps limited to values somewhere in the reddish/blueish spectrum? Isn’t the gray background very non-random?

    Apparently the camera is accessible in the lobby. They say people walking in front of the camera adds randomness. If I go there and hold a photo in front of the camera which I know the values of, doesn’t that compromise everything?

    To be fair their site says they take the lava lamp output and combine it with entropy from two servers and probably do a lot of other stuff before actually getting random numbers. But I don’t get how the lava lamps photo setup is even close to being random

    tried and failed to add image, so here a link: https://www.cloudflare.com/learning/ssl/lava-lamp-encryption/