itt nightquest humming noise

[saturnsc2]

i just bought a nice used itt gen 3 160 nightquest. it works great, the image is very bright & clear with no spots in the field of view. it was very well cared for it looks like. i noticed when the unit is on you hear a very faint very high pitched hum from in the unit when you put it to your ear. when it's off it stops. is this normal? i know a lot of gen 1 units do this but i never heard a gen 3 do this, unless some really do & i never paid attention to this.....

 

[Vinniec5]

Yes very normal Gen2s have it too its the high voltage supply for the tube like a mini TV tube. Very faint but its there on the AN/PVS-4 with gen 2 and gen2 high performance tubes no worries

 

[saturnsc2]

Yes very normal Gen2s have it too its the high voltage supply for the tube like a mini TV tube. Very faint but its there on the AN/PVS-4 with gen 2 and gen2 high performance tubes no worries

ya i figured as so. the old russian gen 1 binocs i once had, had a very loud whine while this one is very faint but there. i never noticed this on a gen 3 or 2 but i guess i wasn't looking for it....

 

[Japanese]

You might have an omni 7 pinnacle auto gated tube inside. :naughty:

 

[saturnsc2]

You might have an omni 7 pinnacle auto gated tube inside. :naughty:

to my knowledge these viewers had unique tubes made for them & no others fit. it doesn't look like this unit was ever taken apart anyway, it's in mint condition....

why does that omni tube make that type of noise when it operates?