Howdy folks,

Still new here, however been messing with NV since my Jr High School science fair project in which I built a GEN0 scope using that old 1602 'nam tube. I'm also a flight simulation engineer.

I have a NAIT NVPS-10 NV unit I bought from a dealer back in 1995. Over time the plastic housing is now cracking and falling apart. Last time I tried to power it up, I had to squeeze from the front to rear just to light up the tube. The original dealer said these sometimes do degrade over time, not the IIT but the housing! I call NAIT hoping they had a spare housing laying around some where, nope. So I'm removing the IIT and plan to install it into a PVS-14 housing.

So, I managed to remove the IIT successfully, well sort of. I removed the front objective mounting plate and the rear ocular plate. Then blue painters tape over the front of the tube and used a medicine bottle to press the tube out the back of the housing. Even thought it came out fairly easily, I then observed that the housing did not have contacts but two small gauge wires soldered to the tube contact and housing. The solders joint were small and the wire separated from the tube without any issues. So be it, the housing is junk anyway.

Now is when it gets bad. I removed the IIT from a plastic sleeve surround it and found corrosion all over the tube! Damn, how did this get like this. Well if you look at the corrosion pattern it definitely was like that when it was installed as that pattern does not match the plastic sleeve at all. The corrosion rectangle around the contacts, well this tube is used and was pulled from god knows what. I treated this unit carefully, it has never gotten wet.

IIT Corrosion!


Next message will be more images as soon as I get the time.

---

I believe that the image links to my dropbox account is working now, so I will continue. Here are some images from removing the IIT from the NPVS-10 housing.

Side View of the Complete Unit:


Rear View:


Front View:


Taken Apart and Laid Out:


Housing Falling Apart:


IIT Wires:


Now, here is where I said "WTF!!!?" Notice the corrosion pattern (rectangle around the contacts) on the tube. Looks like it was removed from another device and transferred to this scope. I see no reason this would have occurred while I had owned it.

Tube still in plastic holder, notice the opening for wiring access:



Images of the corrosion on the IIT after removal from the plastic sleeve:




Tube appears to be a Omni I device per the spec sheet I found:
MX10160
lp/mm: 36
Grade: A-
Gain: 28,000
MFG: ITT or Litton
Condition: New MIL SPEC

Wish I had inspected this tube when I first bought it in 1995. What do you expert opininos say on all of this?

---

Those NAIT monocular are very notorious for issues. I have seen three of them on eBay in the past 6 months and all of them had issues, as well as ancient tubes. I recently talked to one of my night vision repair buddies and this is what he had to say about them, "You mentioned NAIT monoculars - stay away from those!  I have worked on a number of those and they all had dulling corrosion on the Aluminum battery caps and housing threads.  Even the best treatment for that corrosion only seems to work for only 60 days and it comes back and stops the unit from working.  Many of those are sold new with cheap alkaline batteries many Customers leave in for long periods of time that leak and damage the insides of those NVMs.  The last two that were sent to me were Gen III and the tubes dated back to a company that made them for the first ANVIS-6s that were fielded making the tubes over 30 years old and at best 46lp/mm resolution."

The good news is that as long as you clean up the corrosion a bit, it should be easy to swap the tube into a new housing. You're holding history with such an old Gen 3 IIT

If you don't feel comfortable swapping it into a new housing I could do it for you. I'm starting up my own night vision repair/assembly business.

There is a cheap solution for a housing using your lenses, the tube sleeve, and the flange that the C-mount objective lens screws into, and parts of the original housing if you are willing to do some tinkering. All those parts are compatible with an empty aluminum PVS-5 tube housing "can", the eyepiece lens on your housing is actually a Mil-spec PVS-5 lens, and will work perfectly with the PVS-5 can that it originally came from. The mounting flange for the objective lens will work as well, the four holes that secure it to your housing line up perfectly with the holes on a PVS-5 tube housing, you can probably even re-use the screws from your housing. The power switch and IR LED are also PVS-5 parts.   The NVPS-10 was originally designed to use surplus PVS-5 tubes and parts, and when NAIT started installing ANVIS tubes in these, they had to use a tube sleeve to make them fit because of the smaller diameter of of the Gen III tubes. If you go this route you will have to fabricate a battery/switch housing for it, or if the battery section of the NAIT housing is still usable you could cut it away from the rest of the housing and epoxy it to the PVS-5 can.    I`ve owned quite a few of these and did this with a non-functional one I bought on Ebay for peanuts, I used to buy every broken one I could find because the crappy housings were always the problem, out of all of them I only had one with a dead tube. I`ll dig through my photos and post some pics. edit - I forgot to add, you can get dead PVS-5 tubes in the housing for $35 on ebay for two.

Just getting around and back to this. I appreciate the information, yep the NAIT just fell apart, the material they used for the housing just started cracking and falling apart, in particular on the front and rear of the housings. I purchased a Carson PVS-14 housing and swapped in that old tube. What an improvement with the new optics/glass. Now it's got a new life for now as I plan on getting a newer tube. It is very old and at 46lp/mm, but it will get me through.

Thanks again

---