A quick class on MHZ and what they mean.

[Sir Kenyth]

Quick class time.

Frequency is the number of oscillations in one second that an altenating electrical current has. An oscillation is the complete cycle of the current switching from positive to negative. For instance, your wall outlet runs at 60 hertz(oscillations). The nice thing about alternating current is that, because it has a repeating cycle or pattern of changes, we can encode messages by changing that cycle. We can change either the strength of the current, or the frequency of the signal to encode data. This is known as amplitude modulation and frequency modulation. You're probably most familiar with the concept as it's used with radio signals. The AM band uses amplitude modulation and the FM band uses frequency modulation. Computers use amplitude modulation to encode bits. Each oscillation is able to carry one bit of data, a zero or a 1, depending on the voltage of the current at that oscillation. Electrical circuits all have what's called a resonant frequency. Resonant means that the circuit naturally likes to electrically vibrate at that frequency because of it's physical properties. Just like a guitar string likes to vibrate at one sound (frequency) when you pluck it because of it's physical properties. The sound you hear when you pluck the string is the resonant audio frequency of that string. It's the same basic concept with electrical currents. Anyway, if you try to force a frequency into a non-resonant circuit, it resists the current. Resistence, as most know, generates heat. This particular kind of resistance is called reactance. We can never make a perfectly resonant circuit, so there's always some heat generated. The further off you are, the more heat that is produced, and the weaker the transmitted signal is because it loses it's energy to heat generation. Since we are using amplitudal modulation, signal strength is very important. If none of the signal reaches the voltage threshhold to be regarded as a "1", there will be no data transferred. Chips are tested at the factory for how they handle frequencies. In micro-circuitry, very small production differences can make a big impact on resonance. Many don't even make the cut. Anyway, the chips are then rated for a certain frequency depending on their performance. Your motherboard controls the injected electrical signals frequency. It uses one or more base frequency oscillators to generate the bus clock (100,133,166,etc.)and then uses a frequency multiplier circuits to get the higher frequencies required by the processor. You can try to force the chip to operate at a higher frequency than it is rated by manipulating the base frequency or the clock multiplier. This is called overclocking. Manufactures have tried to prevent this by putting the multiplier circuit on the processor itself and fixing it a certain value. This prevents most manipulation.

[ 04-14-2003, 01:34 PM: Message edited by: Sir Kenyth ]

[realbinky]

A Hertz is actually 1 cycle/second not minute. They used to be called just cycles, but that wasn't an accurate terminology, as it referred to cycles PER SECOND. A megahertz is a million hertz per second.

[Timber Loftis]

Thag... head.... hurt.

[Seraph]

Frequency is the number of oscillations in one minute that an altenating electrical current has.

Hertz = s^(-1), in english, its the number of oscillations in one second, not one minute.

The nice thing about alternating current is that, because it has a repeating cycle or pattern of changes, we can encode messages by changing that cycle. We can change either the strength of the current, or the frequency of the signal to encode data. This is known as amplitude modulation and frequency modulation. You're probably most familiar with the concept as it's used with radio signals. The AM band uses amplitude modulation and the FM band uses frequency modulation.

All the stuff about frequency modulation was not needed for this, and only serves to confuse and cloud the point of the post.

[ 04-14-2003, 01:23 PM: Message edited by: Seraph ]

[Sir Kenyth]

Originally posted by realbinky: A Hertz is actually 1 cycle/second not minute. They used to be called just cycles, but that wasn't an accurate terminology, as it referred to cycles PER SECOND. A megahertz is a million hertz per second.

I knew that. My bad! [img]smile.gif[/img]

[Sir Kenyth]

Originally posted by Seraph: Quote: Frequency is the number of oscillations in one minute that an altenating electrical current has.

Hertz = s^(-1), in english, its the number of oscillations in one second, not one minute.

The nice thing about alternating current is that, because it has a repeating cycle or pattern of changes, we can encode messages by changing that cycle. We can change either the strength of the current, or the frequency of the signal to encode data. This is known as amplitude modulation and frequency modulation. You're probably most familiar with the concept as it's used with radio signals. The AM band uses amplitude modulation and the FM band uses frequency modulation.

All the stuff about frequency modulation was not needed for this, and only serves to confuse and cloud the point of the post.[/QUOTE]Everyone's a critic! [img]graemlins/moon.gif[/img]

[Ronn_Bman]

Originally posted by Sir Kenyth: Everyone's a critic! [img]graemlins/moon.gif[/img]

That Hertz, it really Hertz. [img]tongue.gif[/img]

[Sir Kenyth]

Originally posted by Ronn_Bman: Quote: Originally posted by Sir Kenyth: Everyone's a critic! [img]graemlins/moon.gif[/img]

That Hertz, it really Hertz. [img]tongue.gif[/img] [/QUOTE]*Cymbal clash*

Ron- "I've got a million of 'em folks! A million of 'em! Heh! Too bad for you!"

[img]tongue.gif[/img]

[Night Stalker]

*hides BSEE from view*

I thought Megahertz was the Luxury Car Upgrade Plan from that car rental place ..... [img]tongue.gif[/img]