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NVGs TM F4949-1 > NVG > Flashcards

Flashcards in NVG Deck (25)
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1

What type of batteries does the 4949 use?

AA 1.5 volts, no more. No rechargables

2

What is the field of view of our NVGs?

40 degrees

3

What Magnification do the goggles provide.

None, they are 1:1

4

How many G’s are the goggles break away good for .

11 to 15g’s

5

How much do the goggles weigh?

1.70 lbs.

6

How many adjustment are there of the F4949

6

7

Name the adjustments on the F4949

Fore-aft, inter-pupillary, tilt, objective focus, eyepiece diopter

8

How do you know when battery is low?

low battery indicator red flashing light

9

What are the Unacceptable Faults of the NVG ?

Shading
Edge Glow
Flashing, Flickering, or Intermittent Operation

10

What causes Shading.

Occurs when the MCP shifts from the NVG’s being dropped or mishandled.

11

What is a possible cause of Edge Glow?

Can also result from MCP shift.
Confirm by cupping hands over objective lens.

12

Flashing,flickering, or intermittent Operation causes.

May occur in both tubes.
Can be caused by faulty power supply or loose battery cap.

13

What are the acceptable faults?

Bright Spots, Emission Points, Distortion, veiling glare

14

What are Bright Spots.

May flicker or remain constant.
If they disappear when hand covers lens, its a bright spot.
Defect in either phosphor screen, or aluminum oxide film covering MCP.

15

What are Emission Points?

May flicker or remain constant.
If they remain when hand covers lens, then it is an Emission Point.
Caused by an object between photocathode and MCP.

16

Acceptable Faults are?

Black spots
Chicken Wire
Fixed Noise Pattern
Image Disparity
Output Brightness Variation

17

What caution must be exercised when removing goggles from mount?

Do not twist, pull the goggles straight out with even pressure.

18

What is the inspection period for the NVG’s?

180 days

19

When replacing batteries you should always do what?

Turn battery back off!

20

Which battery set is the primary?

Right Side

21

What are the names of the two focus rings?

Outer: Objective Focus Ring
Inner: Eyepiece focus ring.

22

What powers the low battery indicator?

Either battery compartment which ever has highest voltage.

23

Name the six adjustments on the F4949?

Vertical
Fore Aft
Eyepiece
Objective
Tilt
Eye Span or Inter-pupillary

24

Simply put how do the NVG’s work?

They take ambient light and intensify it approximately 6000 times.

25

What is the average life of two AA batteries in the F4949?

Approximately 22 hours at 73 degrees F.