Originally there were four completely independent modules which could be operated together or separately with a peak power of ~2 MW each. Three of those modules have been converted to a new design using modern tubes and each of these new modules can deliver a peak power of ~1.5 MW, with a maximum duty cycle of 6%, and pulses as short as 1.0 µs (Main transmitters). Pulses as long as 2 ms show little power drop; considerably longer pulses are probably possible. The other module is currently unavailable until their conversion is complete. These transmitters use 100 kW peak-power drivers that could also be used for transmission if less power is needed.
In addition, there are four so-called MST transmitters, originally used at Poker Flat. These transmitters can deliver 30 kW peak power, with a maximum duty cycle of 2% and a maximum pulse length of 10 km. These transmitters are usually employed in the “JULIA” mode.