GK-71 (ГК-71) Power Pentode

GK-71 (ГК-71) is a somewhat similar (but not the same) to the famous 813 by RCA. There was another soviet replica of RCA 813 - GU-13.
GK-71 (ГК-71) has a narrower frequency range and a slightly less gain than, say, GU-13 tube, but there are some advantages - it was dirt-cheap and has a terrific endurance (resultant of massive graphite anode block and durable heavy-duty construction).
Possible, GK-71 was the most popular power tube in the AM pirate's anti-society. I'm not quite sure, I have no statistical data of pirate's preferences, but all of my unsocial friends was a GK-71 boosters.
At the other hand, this power pentode was a "Full Legal Limit" tube to the HAM Radio amateurs and one GK-71 final have to be approved without power measuring. I've heard rumours about the one GK-71 tube multy-megawatters, asbestos glove for quick tube replacement etcetera, but reality is slightly less wondrous - 350 watts from one tube without overheating, up to 450-500 watts if you are out-and-outer.

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CHARACTERISTICS

Filament Voltage	20 volts	GK-71
Filament Current	3 amps.
Input Capacitance	18 mmfd.
Output Capacitance	17 mmfd.
Grid to Plate Capacitance	0.15 mmfd.
Maximum Plate Dissipation	125 watts
Maximum Screen Dissipation	25 watts
Frequency Range	up to 20 Mc
Height	195 mm.
Diameter	68 mm.

APPLIED CW CHARACTERISTICS

class	+plate	+screen	bias	Ia0	Ia	~V in	~P in	Ra	Po	Ri
C	1.5kV	400V	-120V	-	260mA	240V	2.5W	3.2k	275W	-
B	1.25kV	400V	-120V	-	270mA	240V	3W	2.7k	230W	-

APPLIED SSB CHARACTERISTICS

class	+plate	+screen	bias	Ia0	Ia	~V in	~P in	Ra	Po	Ri
AB1	1.5kV	600V	-105V	70mA	160mA	105V	0	5.7k	140W	-
B	1.5kV	400V	-65V	60mA	200mA	125V	0.4W	4.4k	200W	-

APPLIED SSB CHARACTERISTICS (Grounded Grids)

class	+plate	+screen	bias	Ia0	Ia	~V in	~P in	Ra	Po	Ri
Bgg	2kV	0	0	18mA	220mA	133V	36W	5.5k	300W	350

Authentic xUSSR GK-71 (ГК-71) HF Power Pentode

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