The STF Basic Tech Manual

Communications

Bradley Joy

Ship-to-ship communications send a signal through subspace at warp 9.9997 and can travel for a distance of 22.65 lightyears. After this point the signal is too degraded and must be amplified by a subspace relay. Because the signal travels through subspace, subspace interference or tetryon bursts can interfere with it.

Intraship and ship-to-shore communications use radio frequencies (which commbadges can receive and transmit).

Comments by Ton Geurts
Can new and improved technologies enhance that the 22.65 ly limit by 5, 10 or 20% as sensors work through subspace as well and have a much wider range? At the NNP Sensor Classification Chart you can see that Starbases and Outposts can do passive sensors scans up to 51 ly. That would mean they can pick a subspace message you've sent even if you cannot receive their the answer.
On the other hand no ship, no outpost or starbase can do an active scan for more than 5/12.5/15 ly, according to the NNP. It implies active scanning is much more dificult than communication (limit 22.65 ly).

Computers

This technology has yet not been explained here.

Holodecks

Steve Johnson

Holodeck is a combination of holoprojectors and replicators. Almost everything that you touch, is replicated. That's how you come out wet. And you don't hit a wall, because of relative position. Your position doesn't actually change most likely. It's like a tread mill. Your actually staying in one spot.

Impulse

Bradley Joy and Owen Townes

Impulse is the primary method of sub-lightspeed travel in the Star Trek universe. Fusion generators create high-energy particles which are accelerated out the back of the impulse drive, pushing the ship forward.

Full impulse for the Galaxy class is .25c (or one fourth the speed of light). Ship classes which need to go faster can have full impulse speeds as high as .3c. Smaller vessels, especially fighters, can have speeds as high as .35c. The reason for these limits is that time dilation, an effect of high-speed travel in which the traveler's personal time runs slower than the time of somebody standing still, begins to cause serious problems around .4c.

Life Support

This Technology has not yet been explained here

PADDS and LCARS

Phillip Stonness and Owen Townes

LCARS is simply the interface (like Windows, but better) for accessing data in the ship's computer. PADDs are wireless, hand-held terminals.

Phasers

Bradley Joy and Barrett Vogtman

All phasers have a certain number of emitters. These are the part of the phaser than actually generates and emits (read: fires) the beam. These are arranged in a bank/array (a collection of emitters) or cannon (usually refers to Pulse Phasers). Cannons use a standard emitter. The beam is collected and releases in small amounts, creating a burst of onion-shaped pulses. Cannon can also mean a beam weapon that fires in only one direction.

A handheld variant of the pulse phaser is the compression rifle. These are improved versions of the standard phaser rifle, which compresses the beam into a burst of energy.

Phaser power is indicated by the type:

Personal Phasers:

Type I: Small, palm-sized phasers that have various settings from light stun up through overload.

Type II: Similar to a Type I, but having a pistol grip attached for added power and stability in aiming. Also has same settings.

Type III: A phaser rifle with more power than the Type I or II. Also has the same settings.

Type III-C (Compression): See above

Vehicle Phasers:

Type IV: Medium-sized variety of phaser that can be mounted on small vehicles. Shuttlecraft can be equipped with phasers of this type, but most shuttles did not carry type-4 phasers as standard equipment.

Type VIII: The lowest level starship phaser. Some have the pulse compression wave.

Type X: More advanced and more powerful for then the type VIII. Usually has the pulse compression wave.

Type X+: Only used on stations and for planetary defenses. They are too powerful to be used on a ship. All have the pulse compression wave.

Comments by Ton Geurts
For RPing the range is an important issue as well. The ranges mentioned in the NNP appear are far too low for 24th century weaponry. They are type I 27 mtrs (30 yrds), type II 40 mtrs, type III 400 mtrs, and type III-c 600 mtrs. 20 years ago standard army riffles had an effective range 300 meters. The bigger the distance the more inaccurate the shot because of the difference in the ballistic objects (bullets) and the parabolic path that goes with them. Phasers have no balistical drawback, and in 400 years we didn't get the effective range up to more than the double?
Besides that, what really helps with aiming is the energy track you can see when you fire. It makes corrections very easy and increases the effective range by some factor.
A more credible estimate for the effective firing range of portable phasers is
Type-I handheld: 50 meters (55 yrds)
Type-II handheld: 90 meters (100 yrds)
Type-III rifle: 800 meters (1/2 mile)
Type-IIIc rifle: 1200 meters (3/4 mile)

Comments by Larry Garfield
Type I phasers have 8 power settings. Type II phasers have 16 power settings, the same 8 plus 8 more powerful ones, all involving high proportions of nuclear disruption energy. Type III have the same 16 settings as Type II, but 50% higher power reserves (bigger battery).
(ST:TNG Technical Manual)

Sensors

Steve Johnson and Owen Townes

There are two modes of sensors, active and passive.

In passive mode the sensors merely detect energy (in the form of light or other electromagnetism) given off by an object or reflected by it from other sources. In active mode the vessel sends out waves of such energy and reads the energy bounced back from the object (shining a flashlight in the dark to see what light bounces back to you).

Ranges are typically given in lightyears, meaning that the signal goes faster-than-light. It is generally assumed that the signal travels through subspace, much like a communication signal.

At longer ranges the signal picked up by active or passive sensors will be interfered with by dust particles, other energy sources, etc, making it harder to read. Therefore the range of a sensor is based on its ability to pick out the signal its looking for through all of this interference.

Comments by Ton Geurts
I don't know if this explanation is founded on canon sources, but I hesitate to accept this explanation.
"Passive sensors only detect electromagnetic energy. [...] The signals travel faster than light." Does that mean that light travels faster than light without any aid? A 20th century theory on relativity claims that is impossible. If you use some gadgets (= active mode) you can get above-c speeds (c is a constant for the speed of light), but not without. Not with passive scans.

Another explanation can be this. Sensors are a kind of subspatial sonar. A variation on 20th/21st century submarines. They too had active and passive sensors. Active sonar sends out pings and listens to the respons, Passive just listens to the sounds in the environment. Active is detectable, passive isn't. Subspatial sonar can be n-dimensional. That way it is more believable the sensors have a range of lightyears.
It will make it also better to understand why sensors can pick up a warp trail. The explanation about warp mentions contraction and expansion of the space surrounding the ship. This will make electromagnetic waves bend around it. That means WARP speed is cloacking sub-lightspeed observation. With subspatial sonar you can actually see the subspace distortion the warp field has created.

Shields

This technology has yet not been explained here.

Tetryon Pulse Weapons

Bret Godfrey

(For those saying "Huh?" these are the shoulder cannons used in Star Trek Insurrection)

Tetryons can only exist in subspace. A small subspace field is created with in the cannon. The small subspace field "contains" the tetryon particles generated until it is accelerated out of the discharge chamber and out towards the intended target.

When the tetryon pulse hits something in normal space, the subspace field around the tetryon particles dissolves and the entire kinetic energy stored within is released. That means that if the weapon is used in anything but a perfect vacuum, it has a very limited range.

I'm not sure if we can actually state the effects of an atmosphere, dust or gas cloud has on the range since that all depends on the density of the matter in question. The denser the gas cloud (for example) the less range the weapon has.

The Encyclopedia states that:

1) Tetryon fields have an adverse effect on warp engines.

2) Tetryon Beams can be used to disable a target ship's weapon's systems.

Torpedoes

Amanda Noon, Israel Harris, and Owen Townes

Torpedoes come in three varieties seen in the series thus far (except for Enterprise). These are Photon, Quantum, and Tricobalt Devices.

Photon torpedoes are the basic, most common torpedo in Star Trek. They work by combining matter and anti-matter to generate an annihilation explosion. They have a range of 3.5 million km and can travel at warp speeds (when launched at warp).

Quantum torpedoes are more powerful, but also much less commonly used. These work by contracting space around a singularity and storing energy in that spatial distortion until the torpedo hits its target, when the singularity degrades and releases that energy in an explosion. Range and speed are identical to photorps.

Tricobalt Devices are chemical/nuclear explosives, intended for use in mining, though Voyager used them as weapons.

Comments by Amanda Noon
Imagine holding a rubber ball in your hand and squeezing it. This stores energy... as you let go think what happens to the ball. It explodes out of your hand. Just as the Quantum torpedo would release energy.

Tractor Beam

This technology has yet not been explained here.

Transporters and Replicators

Ton Geurts, Barry Vogtman, and Owen Townes

Transporters and Replicators are in many ways similar, and should therefore be discussed here.

Transporters scan the person or thing being transported and then dissolve him. Yes, you technically die. But every quantum state in your body (the position, direction and velocity of every sub-atomic particle and the quarks that make those up) is stored in the pattern buffer before this dissolution. Then the pattern and the energy to remake you are transmitted to the destination, where the energy is reformed into the matter according to the pattern, exactly as you were on the transporter pad.

Replicators work in much the same way, but they don't care about getting to the quantum level, they just replicate the right molecules. They do this by taking formless matter stored in the ship and dissolving it into energy, and then they impose a molecular pattern of a substance (food, clothing, whatever) onto the energy, allowing it to rematerialize as the desired object. Cargo transporters work at this molecular level of resolution, and are therefore not suggested for transporting living tissue unless modified.

Comments by Isreal Harris
All transporters are capable of living tissue transport, and are capable of selection of resolutions. The only thing is how much matter can be transported at once, and what the transporter in question is normaly set to.

Warp Drive

Owen Townes

(For a more, in fact way more, detailed description of warp drive, see Larry Garfield's Why Warp Works)

Warp Drive is the sole means of traveling faster than light speed (which is 300,000 km/sec). It functions, in a sense, by expanding space behind the vessel and contracting space in front of it, thus the "warp". Warp Drive accomplishes this by generating a bubble of subspace waves generated in such a way as to provide forward propulsion (nothing is shot out of the back end of the ship to push it forward). Increased speed is caused by an increase in the frequency of bubble generation.

Go to Bret Godfrey's chart of TOS and TNG warp speeds for an overview of warp speeds.