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You can use a germanium diode or even Shottky now instead of a “crystal”.

Such a simple radio can be a gateway drug to a very complex and deep hobby. In my case it went like that:

1. Built a simple radio

2. Could hardly hear anything, need to add an amplifier to it 3. Now it’s better but captures a lot of noise

4. Design a filter to select just that one station

5. Now I want to listen to more stations.

6. Ugh, you can’t design a good filter with variable frequency. Enter the superheterodyne world.

7. Now finally got something that resembles a tunable AM radio, but it kinda whistles / hums a lot. Ah, so the mirror image is a real thing?!

8. Need a higher IF to be able to better reject the image before the mixer. Ok, let’s make a double conversion superhet then.

9. Buy a set of ceramic filters and play with them to get the best selectivity.

10. Try to add more amplification only to learn if you go too far you get an oscillator instead of an amplifier.

11. The sound level is not stable. Add AGC.

12. Pick up some stations from 5000+ km away. Nice. But there is some weird distortion. Oh, I’ve been a culprit of frequency selective fading…

Fast forward and now I’m building a PLL synchronized AM product demodulator with a squaring loop for carrier recovery.

Fun. Lot of fun! Wholeheartedly recommend!


"Almost completely boiled frog petitions against raising the water temperature another degree"

It's great to see that some more people who were previously complacent are outraged about this move. But let's look back a bit:

In the early 1990s, Linus Torvalds started writing an OS kernel for 386-class PCs. He didn't need the approval of some corporation to allow him to run code on his own machine, or distribute it for others to run on theirs. The code didn't have to run as an "app" in some restricted sandbox under Microsoft's OS (not that back then, DOS or Windows were even in any way locked down the way modern operating systems are). Documentation for all the "standard" hardware like video, keyboard, hard disks, etc. was openly available, so it didn't have to rely on proprietary drivers.

This is how it was at one time, and what should have remained the standard today, but instead it's turned into some utopian dream that those who grew up with "smart" devices can't even conceive as possible anymore.

Google has taken what became of this code, and turned it into an "open" system that is pretty much designed to track every aspect of people's lives in order to more effectively target them with psychological manipulation, which is what advertisements really are. And you're not really getting "free stuff" in return for this invasion either, since pretty much everything you buy includes a hidden "tax" that goes to support this massive industry.

"A supercomputer in everyone's pocket"? Yes, but it's not yours, nor can you even know what it does. Even the source code that is available is millions of lines that you couldn't inspect in all your lifetime. Online 24/7, with GPS tracking your every move and a microphone that listens to what you say. Every URL you visit is logged. Your photos uploaded to "the cloud" and used to train AI.

The only solution is to no longer accept any of this, even if almost everyone else does. Even if it means giving up some convenience.

Google has to be destroyed.


Incomprehensible hen-scratch is pretty anonymous.

I thought they turned sycophancy off...

To the "I wish HN would stay out of politics" crew.

You can stay out of politics, but politics will always come and find you.


When I was 10 I wrote my first poem for a class assignment. It was worse than you might expect. The problem is that my teacher entered it into a statewide contest and it got published on the cover of a statewide distributed poetry book. I have a friend who still quotes from it in wonder. I was mortified and it was also the last poem I ever wrote. But my poetry publishing batting average is 1.000.

What’s the opposite of a fun fact

They found the bottom of the uncanny valley and started digging.

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