Hacker News: pps43

New comment by pps43 in "Max: Boeing 'inappropriately coached' pilots in test after crashes"

pps43 — Sat, 19 Dec 2020 14:43:41 +0000

If Boeing goes under, then Airbus becomes a monopoly.

New comment by pps43 in "Summary of the Amazon Kinesis Event in the Northern Virginia (US-East-1) Region"

pps43 — Sat, 28 Nov 2020 13:20:58 +0000

> the new capacity had caused all of the servers in the fleet to exceed the maximum number of threads allowed by an operating system configuration. [...] We didn’t want to increase the operating system limit without further testing

Is it because operating system configuration is managed by a different team within the organization?

New comment by pps43 in "Java is better than C++ for high speed trading systems"

pps43 — Thu, 26 Nov 2020 13:56:11 +0000

You can convert between financial loss and loss of human life using implied cost of averting a fatality [1], which is about $10 million.

[1] https://en.wikipedia.org/wiki/Value_of_life

New comment by pps43 in "Apple’s head of security indicted in Santa Clara County CCW case"

pps43 — Mon, 23 Nov 2020 23:38:23 +0000

Yet somehow the 1st or 5th Amendment are applied across all states uniformly, unlike the 2nd.

New comment by pps43 in "It is high time we let go of the Mersenne Twister (2019)"

pps43 — Sat, 21 Nov 2020 00:17:44 +0000

I'm using quasi-random generators where I can, and MCG 128 where I can't.

New comment by pps43 in "NYC pilot tries mental health responders in place of police"

pps43 — Sat, 14 Nov 2020 21:19:52 +0000

> disarm the police

> they can exercise their right to carry a personal firearm at their own expense

That's not disarming the police, just making them pay $500 out of pocket.

New comment by pps43 in "Trump's Twitter account hacked after Dutch researcher guessed password?"

pps43 — Thu, 22 Oct 2020 18:26:48 +0000

2020! alone is 5,802 digits long.

New comment by pps43 in "Russia gives Edward Snowden permanent residency"

pps43 — Thu, 22 Oct 2020 17:41:30 +0000

Snowden is against government surveillance. It's hard to argue he can be used to justify SORM.

New comment by pps43 in "Russia gives Edward Snowden permanent residency"

pps43 — Thu, 22 Oct 2020 17:38:03 +0000

To be fair, by going after Snowden the US painted itself anti-free speech and pro-surveillance.

New comment by pps43 in "Trump's Twitter account hacked after Dutch researcher guessed password?"

pps43 — Thu, 22 Oct 2020 16:11:30 +0000

No capital letters, though. It is important to follow all security rules. Weakest link and such. If only his password was Maga2020!, it would be impossible to hack.

New comment by pps43 in "Trump's Twitter account hacked after Dutch researcher guessed password?"

pps43 — Thu, 22 Oct 2020 16:09:47 +0000

Let's see:

* Letters - check

* Numbers - check

* Special symbols - check

So the new, secure, password should be Maga2020!

New comment by pps43 in "How to catch a spy that is using a numbers station – The KGB Experience"

pps43 — Wed, 23 Sep 2020 13:12:16 +0000

> if you know the modulation and the frequency the receiver uses

Number stations on short waves all use AM, so you know the modulation. But you don't need to know it, superhet works the same way with any modulation. You need to know the number station frequency, receiver's intermediate frequency, and guess whether its above or below.

> in such a way that there is absolutely no power radiated out of the reception antenna.

I'm not saying there is absolutely no power radiated out of the reception antenna, only that there is not enough power to reliably detect and localize, given the noise and interference from other sources.

If you want absolutely no power radiated out of the reception antenna, you can still do it. Feed some local oscillator frequency, inverted, into the antenna to cancel the remaining leak. But as far as I know, nobody bothers since some leakage is not a problem.

> Any kind of magnetic or capacitive coupler is bi-directional.

True, but in many designs there's also at least one transistor stage in the preamp, and that is not bi-di. There is some stray capacitance between collector and base, but not much.

> Maybe with today's hardware capabilities it would be possible to pull the whole thing into the digital domain at a very early stage

It is possible, but unnecessary. The last radio I built has quadrature sampling detector with FST3253 and handful of op-amps. Most SDRs also do I/Q sampling with two slow ADCs, much simpler than a single high-speed ADC.

New comment by pps43 in "How to catch a spy that is using a numbers station – The KGB Experience"

pps43 — Tue, 22 Sep 2020 19:29:57 +0000

You can make a small (relative to wavelength) loop antenna that has a sharp minimum, but it will be very inefficient. You want your directional antenna to have a sharp maximum (high gain) so that it can increase signal to noise ratio.

New comment by pps43 in "How to catch a spy that is using a numbers station – The KGB Experience"

pps43 — Tue, 22 Sep 2020 19:18:46 +0000

There is a big difference between spectrum analyzer hooked up directly to the input of the radio and an antenna in a van several blocks away, with reflections and noise thrown in.

New comment by pps43 in "How to catch a spy that is using a numbers station – The KGB Experience"

pps43 — Tue, 22 Sep 2020 02:59:44 +0000

A directional antenna has to be much larger than wavelength. Won't fit in a van if we're talking about HF (with wavelengths measured in tens of meters).

New comment by pps43 in "How to catch a spy that is using a numbers station – The KGB Experience"

pps43 — Tue, 22 Sep 2020 02:54:06 +0000

Initial amplifier does not let much energy flow backwards.

More importantly, there's a lot of background noise on HF bands that will mask that weak signal.

New comment by pps43 in "How to catch a spy that is using a numbers station – The KGB Experience"

pps43 — Mon, 21 Sep 2020 16:32:57 +0000

Only if it's poorly designed (leaks local oscillator frequency back into antenna) and not shielded.

Modern receivers use quadrature sampling detectors rather than traditional superheterodyne. In that setup any leakage would be on the same frequency and harder to detect.

New comment by pps43 in "How to catch a spy that is using a numbers station – The KGB Experience"

pps43 — Mon, 21 Sep 2020 12:50:15 +0000

I expected to see something along the lines of vans with directional antennas driving around Moscow listening for spurious emissions from local oscillators of superheterodyne receivers 465 kHz away from the number station frequency, as in Operation RAFTER.

New comment by pps43 in "On the Use of a Life"

pps43 — Mon, 21 Sep 2020 00:36:52 +0000

There's a good reason why many laws in math and physics have two or three names. They are oftentimes discovered simultaneously by several people and it's not always possible to tell who was first.

New comment by pps43 in "Coronavirus: Why aren’t death rates rising with case numbers? A UK perspective"

pps43 — Thu, 10 Sep 2020 12:32:10 +0000

The underlying assumption behind false positive rate is that tests are independent and identically distributed. If in practice this is not the case, then false positive rate becomes misleading.