The 5556 or GL-556/PJ8 is an RF power triode with an anode dissipation of 7.5 Watts and full power rating to 6 MHz and reduced ratings up to the top of the HF band at 30 MHz.

The design use is as an RF power amplifier and oscillator and alternatively as a modulator.

The wide glass tube envelope is 37 mm in diameter and, excluding the UX4 base pins, is 90 mm tall.

Reference: ⁴⁰³⁸.

 
Pin Connections

UX4	1	2	3	4
	f	a	g1	f

 
Absolute Maximum Operating Conditions^¶

Triode	Vh	Ah	Va	Vg	mAa	ra	gm	μ
	4.5	1.1	350	-20	19	-	-	8.5