Double triodes, hi-durable, long-life >5000h. It may be used as an amplifier, mixer, oscillator or multivibrator over a frequency range AF through VHF.
Tube have military and "OTK" mark.

General characteristics

Type	6N3P	6N3PI	6N3PE
Filament voltage, Volt	6.3	6.3	6.3
Anode voltage, Volt	150	150	150
Grid voltage, Volt	--	--	-2
Resistance in cathode circuit, Ohm	240	240	--

Type	6N3P	6N3PI	6N3PE
Filament (heater) current, mA	350+/-35	350+/-35	350+/-35
Anode current, mA	8.75+/-2.75	8.5+/-3	8.75+/-3.25
Reverse grid current, mkA	£0,1	£0,1	£0,1
Dissipate cathode-heater current, mkA	--	--	--
Mutual conductance, mA/V	4.8-6	5.9+/-1.9	5.9+/-1.9
Gain coefficient	36+/-8	33+/-7	34+/-7
Input resistance (by f=60 MHz), kOhm	14	--	--
Equivalent noise resistance, kOhm	0.7	--	--
Vibration noise (by R_A=2 kOhm), mV	£100	£15	£15
Inter electrode capacitance, pF: input	2.8	2.4+/-0,65	2.4+/-0,65
output	1.4	1.3+/-0.35	1.3+/-0.35
transfer	£1.6	£1.6	£1.6
Operation time, h	³1500	³500	³5000

Limited operating values

Type	6N3P	6N3PI		6N3PE
Filament voltage, V	5,7-6.9		5,7-6.9		6-6.6
Anode voltage, V	300		300		160
Grid voltage, V	--		--		--
Cathode - heater voltage, V	100		160		100
Cathode current, mA	--		18		12
Anode dissipation (on each triode), W	1.5		1.6		1.8
Each triode grid dissipation, W	--		0.1		--
Resistance in grid circuit, MOhm	--		1		1

Operating environmental conditions

Type	6N3P	6N3PI	6N3PE
Acceleration of vibration loads, g	2,5	6	10
by frequencies, Hz	--	10-600	20-600
Acceleration of multiple impacts, g	--	--	150
Acceleration of single impact, g	--	--	500
Continuos acceleration, g	-	--	100
Ambient temperature, C	-60 to +70	-60 to +90	-60 to +150
Relative humidity at up to 40 C, %	98	98	98