View Full Version : AN/PVS-4 Repair Question
Quite some time ago...about 25 years, or perhaps a bit more...a purchased an AN/PVS-4 with 2nd gen. tube.
It's been treated gently over the years, and used only rarely. Unfortunately, a few nights ago I took it out of its case and it wouldn't work.
The batteries aren't the problem - I never leave batteries in, and I installed fresh batteries. It still didn't work. There is no physical damage or corrosion, since it is treated carefully. There was no scintillation from the tube.
I found one business on the web that repairs the device - Night Vision Depot. They seemed like nice folks when I called them, but that's all I know about them.
The problem could, I suppose, range from a switch issue to a failed tube.
Any thoughts about someone I could contact for diagnosis and repair?
Thanks as always for your thoughts.
Try asking at nightvisiononline.com - Its a forum for NVG entutiasts..they seem like a good bunch, and there is a bunch of knowledgable heads gathered in there.
Thank you! I'll give them a try.
Retired W4
10-08-2007, 06:06
I'm no NVG expert, but I have spent a lot of time around them, and spent hundreds of hours with them strapped on my head (mostly AN/PVS-5[modified] and ANVIS-6). The batteries are probably more sensitive to storage conditions than the goggles themselves, especially those used on the older goggles. I have seen whole cases of "new" batteries either not work out of the box, or fail within minutes of turning the devise on. Pretty disconcerting when you are in the middle of a six ship formation and most everybody else is using the same batch of batteries. We determined the massive failures were the result of improper storage (too much time in a container on the Bay of Limon). So the easy route would be to get your hands on some fresh bats.
I used to take our goggles to a repair depot at Ft. Benning for periodic maintenance. They were staffed by DAC (civil service) and/or contractors with the test boxes. BTW purging with dry nitrogen is very important for the health of the tubes. Without a military ID it would be difficult to access a repair depot at, say Ft. Hood, in order to pick the brains of the real experts. That is, the guys who do the repair for DoD.
Good luck.
Do you get the fine, light, high-pitched whine when you turn it on?
The DC from the battery has to be "chopped" into pulses so it can be stepped up to high voltage for the tube, so there is a circuit with a vibrator than generates a faint hum.
No whine=probably a bad power supply, the tube may still be good.
Whine but no scintillation=probably bad tube.
I was just reading an article a few weeks back on the 1st and 2nd generation NOD's. In that article they stated something about turning the NOD on at least once a month if not more in order to keep the the tube (I beleive it was the tube but I could be wrong) healthy. The also stated that what effects NOD's more than anything else was the shelving the NOD instead of giving it a workout.
Thank you all for the good ideas...
Retired W4, I'm working on some local contacts who may be able to pick those brains you suggest.
CSB - there's no whine, so perhaps that's a good sign!
MAB32 - Ouch. I've left it shelved without any use for far too long. This may come under the "lessons learned" category...
Thanks again for the answers!