MIL-PRF-1/779K
TABLE I. Testing and inspection - Continued.
Limits
MIL-STD-1311
Requirement or test
Conditions
Symbol
Unit
method
Min
Max
Conformance inspection, part 3
1506
Heater-cycling life
---
---
Ef = 7.5 V; 1 min "on",
---
---
4 min "off"; Ehk = 135 Vdc;
Eb = Ec = 0 (see note 7)
---
Heater-cycling life-test end point
Heater-cathode leakage
1336
ľAdc
---
30
Ihk
Stability life
1516
---
---
Test condition (1);
---
---
Ec = 0; Rk/k = 68 ohms;
Enk = 135 Vdc;
Rg/g = 1.0 MegΩ; TA = room
0078
---
Stability life-test end point
ĆSm
1306
Change in transconductance (1) of
%
---
10
individual tubes
t
1501
Intermittent life
---
---
Stability life-test conditions;
---
---
TE = 225°C (min)
(see notes 14 and 16)
Intermittent life-test end points (1,000
---
hours)
Inoperatives
---
---
---
---
---
Total grid current
1266
ľAdc
0
-2.5
Ic
If
480
Heater current
1301
mA
400
ĆSm
25
1306
Change in transconductance (1) of
%
---
t
individual tubes
ĆSm
30
Transconductance (2)
1306
%
---
Ef
Ihk
50
Heater-cathode leakage
1336
ľAdc
---
Insulation of electrodes
1211
R
---
E (g to all) = -300 V
Meg
25
E (a to all) = -500 V
---
---
1501
Intermittent life (pulse)
---
---
Test condition (2);
Rb/p = 50 ohms
(see note 15)
---
Intermittent pulse life-test end points
---
---
Inoperative
---
---
---
ik
1296
Pulse cathode current (1)
ma
750
See notes at top of next page.
4