https://www.bhphotovideo.com/c/product/944992-REG/sightmark_sm14064_pvs_14_64_72lp_itt_pinnacle.html

My buddy is selling some of his NODS that he isnt using. One is a Armasight Gen 2+ for 1.5k and the other is a sightmark PVS-14 gen 3 used for 2k (used but mint condition). I know sightmark has a rep for making trash red dots, but what about their PVS-14s. According to my limited research, tubes are made by a few companies, right? So what i'm assuming is that sightmark just assembles it. What you guys think? Should I hop on the PVS-14 gen 3 by Sightmark or just skip out on it.

Buy a built unit from ITT or L3.

$2K for sightmark?

Nope

Milspec housings are made by ITT, L3 and Carson. The first two being higher quality and usually exceed milspec and have are manufactured having very tight tolerances.  The ones made by Carson are milspec but usually just meet the requirements from my experience based on the units ive had come through the doors of my shop for repairs and other work. These are the kits you see sold on ebay usually for around $700 without tube. An ITT or L3 will be a bit more in price and I would expect to pay no less than a grand for a complete housing with optics minus tube. Those prices are for new units.  Im mot sure if the companies you mentioned manufacture their own housings or not, but id guess they probably just buy kits and assemble them into final product to sell to the end user. Thats just my guess though.

ITT (now Harris) and L3 are the two manufacturers of US gen 3 image intensifier tubes and both supply tubes to the US military and mainly to the Army and Navy under the various OMNIBUS tube procurement contracts.

I cant comment on the quality of sightmarks builds however as I havent actually ever had a unit that was put together by them as far as I know. Never had a unit that was sporting their brand on the housing. So I will let someone else answer this part of your question.

Should add the Pinnacle tube that is supposedly in the unit you posted the link of is a good one. So theres that at least. 

Regarding the notion that all tubes are basically the same, so why shouldn't an "off-brand" device be GTG.  Assuming the tube is GTG, you are taking a risk that (all the other) parts are mil-spec or at least up to snuff for what you're doing.  Then you are taking a risk that whoever assembled it, did a good job.  So basically you are gambling that you are getting the same product as from L3/ITT/TNVC with strict(er) QC procedures.  I'm not saying you can't, but I am saying it is a risk.  If you make out, then you just saved 1,000 bucks.  If not, then you will have to put another 1K into it for at least a parts kit, again assuming the tube is good.

Just to continue, the non-US PVS-14's also use non-milspec optics. There are several manufacturers with differing quality. From what I have heard some are actually quite good, but others definitely not. I've seen one set that was bad both in terms of build quality and image quality.

Yeah it's a crap shoot, either you know what to look for, or you could get hosed.  I'd say first time buyers should stick to a good high-end dealer since you don't really know what you don't know.  The more experienced guys can tell the parts apart(!) and build their own, but the beginner is taking risks.  Some guys pull it off, but the ones that don't usually won't admit it on line, so you'll never get the full story.  For every guy that reports a successful gamble, I'll bet there's at least one who got dicked.  

So to the OP, no, there's WIDE variation in the quality of these builds.  I've been reading on this website and then this forum for 10+ years.  Guys are always asking about saving money by going to these fly by night dealers or private sales.  Likely as not, they get dicked instead of a good deal.

I think TGI really offers a good deal to the budget buyer, vs chancing used or unknown source kit.  For about what you'd pay for used gen III, you can get really good gen II with mil-spec quality parts and assembly.  Buying gen III at the 1000-1200 mark is a risky proposition, IMHO.

Just to add to this, a first time diy'er can end up "dicking" themselves over as well if they do not make an effort to learn the propper assembly procedures for the PVS-14. They may have all the highest quality milspec parts by L-3 and or ITT/Harris and a tube with the highest performance specs available, but if they just put it together and dont follow the procedures that are outlined in the TM Then they will more than likeley end up with a unit that does not perform anywhere in line with what it should in respects to the high quality parts that are used to build it. If propper steps arent taken to ensure that small, seemingly unimportant or unknown to the untrained diy'er, aspects of the build are not done properly and correctly, then instead of a quality pvs-14 that performs very well and is a satisfactory unit, the result will be an expensive unit that performs far under what it should and will be more frustrating to use usually than it is enjoyable to use. It will Remain a constant source of headaches to the end user until these issues, caused by incorrect assembly of the unit, are addressed and corrected. If you are building your first pvs-14 or even your 100th, ask yourself this question, "which side/surface of the tube retaining ring should be facing the tubes output end, when it is threaded in to secure the light pipe and tube in the housing?" If you are unsure and cant answer the question with 100% confidence then I suggest either getting the TM from somewhere and reading through it entirely until you can do the procedurwe without the TM and only use it to reference from time to time or have someone who is knowledgable and can build it properly and correctly, the first time, build it for you. 

"then I suggest either getting the TM from somewhere and reading through it entirely until you can do the procedurwe without the TM"
I strongly disagree. Properly assembling a PVS-14 is not rocket science. In fact it's easier than proper disassembly and cleaning of most semi-automatic pistols. YouTube is full of simple tutorials by reputable sources. There is also no reason to memorize the procedure as once it's assembled, there's no reason to disassemble it. Spend the money for a good housing and go for it.

No one suggested it is rocket science, however there are certain things that should be done a certain way which will be explained in the TM. I believe a DIY beginner and even seasoned DIY'ers should view the project, no matter what it is, as a learning experience to make sure that they learn everything they need to do the project correctly and do it the dirst time. I know its not always possible to pull something off successfully right off the bat everytime, but why wouldnt you spend the time to study the neccessary material to learn about the correct procedures to make your project the best I can be. If a DIY'er is starting a new project they have no previous experience with and the sole objective is purely from a stand point of trying to save money and no effort is put forward to learn the correct way to do it, then they will almost certainly do something incorrectly and end up with something that is less than expected and not how they wanted their project to turn out because they had high expectations of quality but didnt feel it important to learn how to work on the project in a correct manner. Id say that when it comes to 14's there are alot of them on ebay that are listed for exactly the reason above. Someone wanted ro save money so tried to build themselves, screwed something up, and were left with the option to either spend more to get whatever they screwed up fixed ot sell it on ebay and recoup the money as 14' hold their resale values very well and usually these are susually sold at lower than normal prices but the fact that they were built incorrectly and have issues stemming from something done incorrectly arent always disclosed to butmyers. I suspect that these units are bought by people who are new to night vision and dont know better and pay a good sum of money to get a pvs-14 and unfortunatley end up with something that was put together in an incorrect fasion. Id think most knowlegable folks would recognise a unit listed as new with a unusually low price pointas one of these types of deals and shy away from purchasing it.

Technical Manuals exist because of the simple fact that things should be done a certain way to get the best performance out if a product. 
Any reputable NV repair shop or builder or anyone assembling pvs-14's and other devices will always have a technical manual on hand for referencing as there is actually quite a bit more than one would think that is contained within the TM in regards to propper procedures. Also learning something once and forgetting it kind of defeats the purpose of a DIY attitude. Fir me when im doing a DIY project I learn as much as possible about the project and procedures to correctly complete the work and also study it as much as possible so thati will be able to successfully repeat the result again if needed. Even if I think ill never use what ive learned from it again because I dont actually know that I wont. If a person isnt going to put effort forth to do a project correctly by learning as much as the can about it, and then forget it once the work has been attempted, and likely failed or turned out half assed and low quality, then they should probably just pay someone to do it the right way abd not try to DIY. Seems like that would be a wast of time start a project with an attitude like that. But thats just my opinion. DIY as i see it means that you end up with a product that you made yourself that is just as good if not better than what can be bought at a store. Usually it will save money, but sometimes may cost more to build yourself. A true DIY'er will still choose to take these on sometimes even though it may cost abit more, simply because they enjoy working on projects and like to learn ehatever possible about a project.

I don't disagree with your  general principles on DIY projects, but short of cross threading something or pulling the pig tail off the tube, what can you screw up that can't be easily fixed assembling a PVS-14?

The cheap PVS-14s for sale that are screwed up were probably screwed up from lasers or other light sources, or mounting to a weapon. I've not heard of anyone getting a PVS-14 that was permanently messed up because of improper assembly? Other than the tube, the rest of the device is rather simple. Other than the tube which drops in and plugs in, all the electronics are in the battery box which you don't service and is inexpensive and super simple to replace. I see the biggest challenge for a DIY PVS-14 project for the novice is knowing what he or she is getting when they buy a tube.

Ive seen plenty of cross threaded units that were sent to me to have the upper replaced, due to the damaged threads, and reassemble the unit . Another form of permanent damage I have seen a few times are units someone put together without setting the infinity focus stop ring correctly. These units usually had the ring threaded all way on and then left like that and a after a few focus adjustments to the lens it is found that the tubes input glass has been marked and scratched up and that could have been avoided by simply learning how to perform the correct assembly procedure. Your correct that a lot of things that are screwed up by novices when assembling the device can be fixed, but the novice screwed it up because they didnt know what they were doing wrong and and upon "completing" the device they find issues that stem from them doing something incorrectly during the build up. Then they will have to either troubleshoot the issue blindly which isnt usually very productive or they will have to pay somebody to fix it for them or they end up selling it on ebay for cheap and if it is bought by another novice they will go through a similar situation. So in cases like that, where a novice just went at it and messed something up, which may be totaly fixable by a more knowledgable individual, but they are lost on what to do next besides one of those three options above. Therefore the issue, at least to the novice who put the device together, may as well be permanent damage if they arent going to put in the effort to learn the proper assembly procedures to fix the problem. The proper procedure should have been studied beforehand and the issues could have been avoided the first time. Also if the point of Diy is to make something as good or better than the product you want to build then it kind of goes without saying that one will have to do a good bit of research on the product and how it works for them to expect a quality result for their build. You may save a little money buying individual parts of the 14 and attempting to assemble it yourself, however that should as I said, be a secondary goal of the DIY build. Learning and experience should be your main reason for attempting a DIY build. Your going to be paying a large sum of money for a 14, regardless of whether you buy one complete and ready to use or if you build it yourself. So if you build it yourself why would you pay all of that money to just throw a 14 together willy nilly like and end up with something that doesnt perform at its best. You may have saved a bit of money building it yourself, but if it wont perform at its best because the time wasnt taken to learn how to make it perform at its best then whats the point? The money saved may not matter too much at that point if you have a unit that needs all kinds of little issues fixed and adjustments made to perform at its highest and if you dont know how to go about doing the fixes and adjustments then likey more money will have to be spent to have someone make them right. I dont know about you but I wouldnt pay all of that money to end up with a sub par result that isnt anywhere close to performing like a unit that was proffesionally built, which is what I wanted. Take it all as my opinion but, I think most would want to build a unit that can match performance of a unit that a pro built and in turn also save a little money by DIY on their first attempt so they have a complete high performance unit and not have to worry about having to fool around with a bunch of issues because of improper assembly. The way I see it, either one would need to be extremely lucky to assemble a very high quality unit without knowing the correct assembly procedures or they would have to have studied, learned, and retained the propper procedures before startng the work. 

There are also alot of little things that one should do to prepare fo the actual build and proper was to handle parts as well as storing them until the build is ready to start. One example of proper handling and storage of 11769 tubes that I dont see often when I see pictures people post of their tubes online or posted in an ebay ad, is that there is no ESD protection, usualy a small block of ESD protective foam, pressed onto the pins on the pcb on the end of the pigtail that plugs into the 14's manual gain circuit. Something that is important and will prevent possible damage to the tubes power supply, but isnt something a person would likey think or assume they should have on the pins when tube is out of the housing or being stored long term while not in a housing, but will protect against damage that is expensive to repair. I rebuild tubes all the time as a service offered and have seen alot of preventable damage that ultimately was sustained due to the lack of small seemingly unimportant things being overlooked. These wouldnt have been an issue if the TM had been studied to learn about the many important preparations that are in the TM and are in there for good reason.

I think both of you guys are partially right.  It is pretty butt-simple to assemble, but you can fuck it up, if you try hard enough.  I have replaced all the parts but the tube, by simply noting where everything was and reassembling it back that way.  That being said, I think it is very good advice to read up on how it's supposed to be done, rather than relying on luck.  The reason I say you're both right is because on the one hand, if a guy is reasonably competent, he can pull this off.  So yeah a good portion of DIY projects work out OK.  But on the other hand, if you're the guy repairing the fuck-ups, you get to see where the guy, who isn't so mechanically inclined, managed to cock something up.  So you realize it is possible to do it wrong if you aren't up to the task; there are DIY projects that break bad.  

So this is a very good (side) discussion between you two guys which points out the ease and complexity of this task.  Some people can do this, some can't.  Some would say it's easy, some would be challenged to do it right.  The key is the individual.

Ya  it did kind of stray from the original topic a little, but it is something that is important and at least is related in a way to the OP. My posts like I said can be viewed as my opinions, but I base my opinions on my experience performing alot of 14 and 11769 repairs as well as countless repairs on a multitude of other devices and tubes and I will say I have seen my fair share of units that come in and they need nothing more than simple adjustments, but when the owner contacted me and described the issue it sounded like a somewhat major repair job would be neccessary.I charge one man hour for most repairs so when I get these units that are reported to be total pieces of trash in need of full ovehaul, but upon receiving the unit, I find that it only needs small fairly "easy to do" stuff like needing the infinity focus stop ring adjusted correctly and the eyepice needs to have some lubricant applied, ect. I then must adjust my quoted cost of repairs to something reflecting the very little bit of work that was actually needed. So it makes it hardly worthwhile for both myself and mostly for the customer who must pay shipping both ways for something so simple that could easily have been done by the owner of the unit had they just took a small amount of time on the weekend or whenever they had some free time to look through TM and found theissue they were having in the troubleshooting section and from that they could easily figure out the correct procedure o fix the issue and how to go through the procedure step by step. When I say that its hardly worth it about these types of situations I mean that I will have cleared part of my day to work on the repair and then end up making the neccessary adjustments in about 10 minutes and I wouldnt be able to sleep at night if I were to charge the customer the full repair cost for only making a few quick adjustments to their unit and the customer who just dropped coin to ship it to me to have it for a total of 10 minutes then has to pay to have it sent back. It will work like they wanted when hey sent it to me after recieving rhe unit back, but they could have saved the money had they instead just spent the time to learn how  to disgnose and fix the issue(s), which is something theTM is svery good and useful for. I dont dislike work and making adjustments is part of any repair job, but having a unit sent in just to have me perform a few simple adjustments isnt really economical for either party. Anyways that is that, hopefully the thread can get back on topic now topic 

I wonder, does NGI use the same housings as TNVC? I assume so, but I figured it would be worth the ask.

Outstanding! Good to know. I use the hell outta my NGI PVS-14+. While I'm thinking about it, I've noticed that on the NGI website, they list only 1 pvs-14 Now rather that 2 like they used to. The advertisement says PVS-14 Gen2+ but the sku says COMSEC. When I purchased mine, it was listed as the PLUS model at the time which was supposed to be a Photonis tube, but after I ordered it and asked about it, they said Photonis was in the process of being bought out. I asked if they might have known what particular model the tube might have been, but due to the buyout they said it could no longer be guaranteed that I got a tube with Photonis markings. Just curious what happened there? I see on the sentinels, they list as still being Photonis tubes,  but not the PVS-14.