If these requirements are met you have the capability of constructing a Tachyon device. If you are lacking any of these resources or requirements you will be unable to build a Tachyon device.
Installing a Tachyon Device
To install the device on to a ship you need to select the FIX mission from the main starbase and a planet friendly code of ITD . When you set these conditions the Tachyon device (which can only be constructed on the same turn it is installed) will be placed on to the ship that was the target of the FIX mission on the starbase.
You will receive a message for a few turns reminding you which ship is equipped with a Tachyon device, so take note, this message will stop eventually.
Tachyon Device Limitations
Tachyon devices can only be constructed in the same turn they are installed. Each race can only build two (2) devices per game. That means over the entire course of the game only two (2) devices can be made and installed on your vessels. Even if the ship is captured or destroyed, you CAN NOT build another device and install it on one of your ships.
If you capture a Tachyon equipped vessel and already have two (2) of your ships equipped with Tachyon devices, this is OK. The rule and code state that you can only BUILD two (2), there is no limit to the number of devices you can control and operate.
Using a Tachyon Device
To use a Tachyon device, you need to have a ship equipped with this device. If a vessel is equipped with a Tachyon device you need to make sure it has fuel and then you decide on how many light years of space you want to effect with the Tachyon device.
Once this is determine the range you set your ships friendly code to TP(n), where (n) is a number between 0-9. This number times 10 (0=10) will be the radius of the Tachyon pulse circle. (i.e., TP0 = a pulse of 100 light year radius.)
Cost of Using The Tachyon Device
The Tachyon device has a base fuel (Neutronium) cost of 200 KT per Tachyon firing. The amount of fuel actually used is based on the radius of the pulse fired. The radius of the pulse is equal to the percentage of the 200 KT base fuel cost.
(i.e., TP5 = 50 Light Year Pulse -- 50 light years = 50% of the 200 KT base fuel cost, thus a 50 LY pulse costs 100 KT of fuel = 200 (base) *.5 (50%).
Effects of a Tachyon Pulse
When a Tachyon pulse is fired it will decloak all vessels in the pulse radius area. The uncloaking will cause their mission to be reset to Exploration. This is caused by the electrical disruption cased by the Tachyon pulse. This decloak will last until the other player resets their mission. So yes, an enemy vessel will be uncloaked for the whole processing of the host (turn).
Warning: The pulse will uncloak your own ships too. And any vessel struck by a Tachyon pulse will receive a message telling them the x,y of the origination point of the pulse and the ID# of the ship that fired it.
When do These Missions Happen?
