The 6BL7GTA is an octal-base high-perveance medium-mu twin triode designed primarily for use as a combined vertical deflection oscillator and amplifier in television receivers. Featuring a 10-watt maximum plate dissipation per section (12 watts total combined), it delivers high current handling and large voltage swing capabilities. The GTA variant incorporates controlled zero-bias plate current ratings and improved oscillator stability over the earlier 6BL7GT. Its robust power capabilities also make it a popular choice for custom audio preamplifiers, driver stages, and low-power headphone output stages. Operates on a 6.3V heater and fits standard 8-pin octal sockets. Available NOS and tested used.