GATE Pulsar S HPA Engine, ASTER II Bluetooth, Rear Wired

The GATE Pulsar S with ASTER II Bluetooth EXPERT is a complete HPA set for V2 gearboxes in the Rear Wired version, where the power wires run to the rear for a battery in the stock or buffer tube. The Pulsar S is a compact HPA engine with one solenoid valve and open-bolt operation, fitted in place of the cylinder, piston and cylinder head, while the ASTER II controls both trigger and valve optically.

The set is GATE's most affordable route to a Bluetooth-controlled HPA replica and is aimed at CQB and speedsoft, where short reaction time and high rate of fire matter most. The electronics sit inside the gearbox, and via the GATE Control Station app you set trigger sensitivity, fire modes and ROF – even out on the field. With only one valve, however, the Pulsar S requires the gearbox to be very precisely aligned with the hop-up chamber.

Pulsar S with ASTER II – key features

Engine and control unit together:

• ASTER II Bluetooth EXPERT: Optical V2 drop-in control unit with Bluetooth 5.2 and EXPERT firmware: SEMI, BINARY, BURST and AUTO, ROF control and magazine simulation – functions that have so far mainly been reserved for AEGs.
• High rate of fire: GATE quotes up to 100 RPS for the set, depending on the magazine – considerably higher than the Pulsar H and Pulsar D, which are around 40 RPS.
• Stabilised nozzle: The dedicated nozzle is extra stabilised for consistent velocity and to avoid mid-cap problems. The nozzle length corresponds to a 21.25–21.40 mm AEG nozzle.
• Compact and light: The engine measures 88 × 25.4 mm and weighs 75 g, and the ASTER II weighs only 23.4 g – leaving room in tight custom builds.
• Multi-function port: Ready for accessories such as a bolt catch button, magazine sensor, tracer in the hop-up chamber, electric magazine feed or light.

Maintenance and safety

• Installing an HPA engine requires experience: the gearbox must be emptied, the engine placed fully forward against the front wall of the gearbox, and wires and air line routed without being pinched. We are happy to fit and set it up in our workshop in Aulum, Denmark. Check the alignment with the nozzle in the forward position and a loaded magazine inserted.
• Only use high-pressure air via a regulator, and keep the operating pressure within 60–140 PSI (approx. 4.1–9.7 bar) – higher pressure can damage the engine. GATE recommends, for example, PolarStar MRS, Redline SFR or Wolverine STORM as regulators. Air consumption is approx. 1 PSI per shot at 90 PSI.
• The ASTER II and valve are powered by a small 7.4 V battery, which with Rear Wired routing is placed at the rear. The purple Pulsar S nozzle must not be used with a stabilising sleeve. The air line has a 6 mm outer diameter and M5×0.8 thread in the engine. A QD fitting (US/EU) is not included and must be bought for your system.
• GATE advises against silicone buckings; Madbull Blue, TNT Black with nub or 4UAD 4UANTUM FRICTION PRO-HIGH are among those recommended. Clean the engine preventively about every six months or in case of malfunctions. The solenoid valve seals are delicate, so only wipe the valve gently – and avoid grease on the flat rear face of the nozzle and at the bottom of the cylinder, as it can stop the nozzle moving.