systemreboot – blog

Frogs, Humans and the Radio

Oct 1, 2012

…in effect, SSB radio is like shouting above the din of the noise existing in the band. The noise always exists in the band, and in order to be heard, one must shout above the noise.

Tags: musing, radio

Halo around Sun in Coimbatore - August 3, 2012

Aug 12, 2012

Coimbatore witnessed a spectacular halo on August 3, 2012… Just wanted to put up a photograph of the halo by my friend Udhaya Kumar…

Tags: weather

Line Codes - Matlab / GNU Octave Code

Jul 19, 2012

I came up with the following approach to do line coding without for loops. My approach involves a bit of system theory, modulo 2 arithmetic, and sometimes just tricks founded on simple coincidence. So one is advised to be a little careful while sifting through the logic. But ultimately, the code is terse and fairly elegant.

Tags: signals, matlab, octave, software

Design of LC Oscillators - Capacitive Overload

Jun 30, 2012

If the frequency was high enough, the capacitor in the tank would draw too much current from the output of the amplifier, and the amplifier would overload killing its gain and bringing the whole system down…

Tags: electronics

Back to Classes - The Last Semester!

Jun 4, 2012

After all the awful places I've been to (Chennai tops that list), Nagercoil is quite a heavenly place. The road to Kanyakumari had good tree cover with the occasional pond and other water bodies providing good relief to the surroundings.

Tags: walk, travel

How do oscillators start up?

May 12, 2012

If you are into oscillator theory, you probably know that oscillations in an oscillator build up exponentially before hitting power supply saturation and stabilizing. Well, at least that is what the textbooks and the equations claim. But, have you ever seen it? :-)

Tags: electronics

Resistance Measurement — Common Mistakes

Apr 29, 2012

A few common and silly mistakes people might make when they are learning to use a multimeter to measure resistances…

Tags: electronics

The Site So Far

Apr 26, 2012

The plans ahead involve running my own server on a BeagleBoard with solar power. But the BeagleBoard plans are pretty long term (possibly more than a year)…

Tags: selfhosting

Convolution and Polynomial Multiplication

Mar 26, 2012

"Convolution in the time domain is multiplication in the frequency domain" is an oft-quoted statement. But the exact relation between the two is seldom stressed adequately. Mathematically, convolution and polynomial multiplication are one and the same process, as I shall explain shortly.

Tags: math, signals

How does convolution work?

Mar 26, 2012

The process of convolution works on the twin concepts of linearity and shift invariance. Here is an animated explanation of the concept.

Tags: math, signals

Modular Exponentiation

Mar 26, 2012

Modular exponentiation is essentially a technique used to calculate c=b

Tags: math

Polynomials are Numbers!

Mar 26, 2012

Polynomials are numbers of an unknown base x…

Tags: math

Newer posts

Older posts