MIL-PRF-1/1394C(USAF)
TABLE I. Testing and inspection.
Limits
Inspection
Method
Conditions
Symbol
Min
Max
Unit
Conformance inspection, part 1
Filament voltage
1261
If = 170 mA dc
Ef
---
20
V dc
Voltage drop
1337
2/
Etd
70
80
V dc
F = 9.0 ± 0.3 percent GHz
Excess noise
---
NR-1
15.40
15.80
db
1/ 3/ 4/ 5/
F = 9.0 ± 0.3 percent GHz
Match (1)
---
VSWR
---
1.1:1
---
Ib =0 4/ 6/
F = 9.0 ± 0.3 percent GHz
Match (2)
---
VSWR
---
1.1:1
---
Ib = 250 mA dc 4/ 6/
Conformance inspection, part 2
Variable frequency vibration
1031
No voltages 9/
---
---
---
---
Conformance inspection, part 3
Intermittent life test
---
Group D; cycle one minute on,
---
2,500
---
Cycles
2 minutes off; preheat time 2 to
3 seconds 3/ 8/
Life test end point:
F = 9.0 ± 0.3 percent GHz
Nr-1
15.35
15.85
db
Excess noise ratio
---
1/ 3/ 4/ 5/
(Te - 1) where Te is the effective electron temperature.
1/ The excess noise ratio (Nr-1) is defined in db as
Nr - 1 = 10 log
290
2/ In the test circuit of figure 4 with a filament current of 170 mA dc, the tube shall operate within three tries.
3/ The tube shall be tested in total darkness.
4/ The tube shall be tested in a tube mount as specified in figure 3, or equivalent, terminated by a matching RG-52/U termination
having a VSWR no greater than 1.01:1 such as a Hewlett-Packard X-914A, or equal. Excess noise ratio measurements tests
shall be made using the circuit of the block diagram of figure 2. Excess noise ratio should be measured by comparison with an
approved standard noise source.
5/ The frequency specified is that of the local oscillator.
6/ The frequency specified is that of a signal generator.
7/ Excess noise ratio shall be measured by comparison with an approved standard.
8/ The tube shall be tested at an ambient temperature of +85°C (185°F).
9/ Intermittent life test end points shall apply.
10/ First article sample inspection shall conform to the requirements of appendix F of MIL-PRF-1 and shall consist of performing all
tests specified on this specification sheet. In addition, first article sample approval shall include satisfactory demonstration of
tube-to-system compatibility. Invitation for bids should provide that the preparing activity reserves right to waive the
requirements for first article samples as to those bidders offering a product which has been previously acquired or tested by the
Government, and that bidders offering such products who wish to rely on such production or test, must furnish evidence with
the bid that prior Government approval is presently appropriate for the pending acquisition.
11/ Unless otherwise specified, the acceptance level for all tests listed under conformance inspection, part 1, shall be 1.0 percent,
inspection level II.
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