6HU6

6HU6 is also designated EM87.

General Description

The 6HU6 is a combined amplifier and level indicator for tape recorder applications. Its indicating pattern is a bar whose length varies with signal strength. The required control voltage to close the light pattern is 10 volts. When signal voltage is increased above 10 volts, the pattern overlaps as a warning against over-modulation.

Construction

The 6HU6 has a T6-1/2 bulb and a Noval base. The heater is indirect, operable on AC or DC, in series or parallel, with a voltage of 6.3 volts and a current of 300 mA.

Ratings

The Amperex datasheet gives maximum plate voltage as 300 volts, with a maximum plate voltage at zero plate current of 550 volts. Maximum deflection electrode voltage is 300 volts, with a maximum of 550 volts at zero current. Maximum fluorescent screen voltage is 300 volts, with a maximum of 550 volts at zero screen current and a minimum of 170 volts. Maximum plate dissipation is 0.6 watts, maximum cathode current is 5 mA, and maximum grid resistor is 3 megohms. Maximum heater-to-cathode voltage is 250 volts, and maximum heater-to-cathode resistance is 100 k ohms. The grid bias for Ig = +0.3 mA is -1.3 volts.

Alternative Data

A French datasheet describes the EM87 as an 'indicateur d'accord' (tuning indicator) with a triode amplifier. That sheet gives the bulb designation as A22-7, the base designation as 9C12 (noval), and a maximum bulb temperature at the hottest point of 120 °C. It also gives a negative shadow length value, meaning that the two luminous parts of the target overlap by 1.5 mm.

Equivalence is asserted only where the archive's own literature states it directly, in at least 40 separate documents. Tubes that merely substitute in some circuits are not listed here.

Original manufacturer datasheets for 6HU6, hosted by Frank Philipse's Electron Tube Data sheets.

Documents held here and used to write this page.

• INDICATEUR D'ACCORD (filed under EM87)
• AMPEREX TUBE TYPE 6HU6/EM87