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Posted: 8/27/2009 4:26:54 AM EDT
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Anyone seen the Wikipedia page on this scope. They have the MX-9644/UV listed as a Gen 3 tube. I have never seen a MX-9644/UV Gen 3 tube. I know the MX-11620 is the Gen 3 replacement. I always thought the 9644 and 9644/UV were all Gen 2 tubes.
http://en.wikipedia.org/wiki/AN/PVS-4 The MX-9644 tube was also continued in the form of the MX9644/UV which was a Gen3 tube with a Gen1 tube cascaded with it, known as a Hybrid tube, to provide far more gain. Hybrid tubes are capable of gains well in excess of 100,000 times. (I pasted this line from the Wiki article) |
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Anyone seen the Wikipedia page on this scope. They have the MX-9644/UV listed as a Gen 3 tube. I have never seen a MX-9644/UV Gen 3 tube. I know the MX-11620 is the Gen 3 replacement. I always thought the 9644 and 9644/UV were all Gen 2 tubes. http://en.wikipedia.org/wiki/AN/PVS-4 The MX-9644 tube was also continued in the form of the MX9644/UV which was a Gen3 tube with a Gen1 tube cascaded with it, known as a Hybrid tube, to provide far more gain. Hybrid tubes are capable of gains well in excess of 100,000 times. (I pasted this line from the Wiki article) Hi Dino, That is correct. You can find some documented reference to the MX9644/UV Gen 3+1 on page 41 of "Image Tubes" by Illes P Csorba... Most Gen3 PVS-4 ( Usually known as the AN/PVS-4A ) would use a MX-11620. That's not a hybrid. As far as I know, it's a FO twisted Gen3 device. Given the authors background, the nature of the documentation and the image of the Gen3+1 hybrid tube, I would guess that the MX9644/UV Gen 3+1 hybrid was a Litton tube. The most common Gen3+1 tube is the ITT F4960 which is used in the Stinger Night Sight. The Gen3 component is the primary photocathode and uses a standard S25 photocathode based Gen1 inverter that's coupled via FO to the Gen3 screen. While Gen3 is pretty good, Gen3+1 is capable of going to the edge of darkness and is able to create a visual representation on a per-photon basis. The only limitation is the wavelength and the quality of the original photocathode, but they have useful gains of over 100,000 (think 314,000 fl/fc !) with very low noise. That's about 5 times what a good Gen3 tube does now. If there's one thing I've learned from reading the forums, it's that there's an incredible amount of information/knowledge and research that's been lost to lack of recording in the NV world. There's so much that simply isn't well known - even recent stuff like the Gen4/Thin-Filmed-Gen3 issue. I'd really like to find out more about that, historically speaking. Regards David. |
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I'm not really sure - I've never seen one, not even a picture for that matter... But I'm guessing it would be a Litton tube, so if you ever see a Litton MX9644/UV, check the photocathode for me - It should look like a MX-11620 or have that typical Gen3 appearance. They should have a normal Gen3 PC integrated into the top piece of glass... Out here in Australia, I'm pretty unlikely to encounter one... Maybe if I'm lucky, Last Lancer will eventually unearth a photo of one :) Though I've heard him make the claim before, so maybe he has seen one? Last Lancer? Any pics? David |
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Found this that Ed wrote about it :
"The first version of the MX-9644/UV in Gen III was a hybrid tube like you described. Its actual designation was (ITT) F4844 and it was designed for use in the "Stinger Night Sight," ITT F4960. The specs were Spectral Response 600 - 900 nm, Resolution 1.8 cy/mr, and System Gain was 1,000 to 8,000 typical. This was not a drop in replacement, for the AN/PVS-4, like the MX-11620/UV is. The F4844 image tube had the focal plane 1/4-inch aft like most Gen III tubes do. AS I remember it was expensive." |
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Found this that Ed wrote about it : "The first version of the MX-9644/UV in Gen III was a hybrid tube like you described. Its actual designation was (ITT) F4844 and it was designed for use in the "Stinger Night Sight," ITT F4960. " Ahh, found some more... Looks like the Wikipedia article needs an update... Thanks :) ITT Defense F4960 Stinger night sight The Stinger night sight is a third-generation image intensifier system based on the AN/PVS-4 weapon sight technology. It incorporates a 60 mm, f1.2 objective lens (which provides a x2.26 magnification and a 23.5° circular field of view) with a 25 mm Gen III+I F4844 image intensifier tube. The spectral response region is from 600 to 900 nm. Total length is 312.4 mm (386.1 mm with the mounting bracket attached), diameter 104.1 mm and weight 1.91 kg (2.27 kg with the bracket). The sight is powered by two AA size alkaline batteries which provide on average up to 30 hours of usage. The illuminated tracking/aiming reticle has a fully adjustable brightness control and is similar to the existing Stinger reticle. The combination of the lens and image intensifier tube allows acquisition of targets at ranges of up to 7,000 m and identification at 4,500 to 5,000 m even under starlight conditions. A total of 150 examples of the sight has been supplied to the US Marine Corps as the interim Stinger night sight system. These were deployed in the Gulf War. |
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When you update maybe you can clarify the MX-9964/UV. As it is written it leads one to believe all MX-9964/UV were the Gen 3+1. While I have never seen the Litton version of this tube I have seen the ITT version and they are Gen 2 (unless there are more of these hybrid tubes from ITT that I have never seen). Just a suggestion as it's a little unclear as it's written.
http://www.fbodaily.com/cbd/archive/2000/08(August)/24-Aug-2000/58sol009.htm The MX-9644 tube was also continued in the form of the MX9644/UV which was a Gen3 tube with a Gen1 tube cascaded with it, known as a Hybrid tube, to provide far more gain. Hybrid tubes are capable of gains well in excess of 100,000 times. (I pasted this line from the Wiki article) |
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cj7hawk - you must be mistaken, buddy, the piece of information that MX-9644 also exists in Gen3+1 is completely new to me. I have never heard about it before, all MX-9644 tubes I have seen are/were Gen2+1.
I have many pictures of the MX-9644 tubes but none of them was produced directly by Litton (read MFR 55311). I have seen some made by ITT (MFR 13567), some by DBA Electro-Optical Systems (MFR 27777), others by OEC/NI-TEC (MFR 51298) or Varo (MFR 66868). MFR 27777 and 51298 later became Litton's subsidiaries and their later MX-11620s were produced exclusively in Garland, TX, never at Tempe, AZ. |
| I have no doubt that a tube of this type exists. I just had issue with it being a MX-9644/UV. It may be under some other designation but I have never seen or heard of a MX-9644/UV being a Gen 3 tube, be it hybrid or anything else. If David has reliable info from his sources on this I would love to see it. Like I said I have no doubt a tube of this type exists but I think it was labeled as something other then a MX-9644/UV. |
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I have no doubt that a tube of this type exists. I just had issue with it being a MX-9644/UV. I'm starting to wonder myself now. I've sent LL the details of the 3+1 MX9644/UV and DS - There's an email waiting for you so I can send it through too - I know there's a lot of anecdotal information on the internet about MX9644/UV being Gen2, but are there any conclusive images of the PC with the designation in the image also? I went looking but didn't find any. Looks like I'll need to dig a little further and update the Wikipedia page to avoid confusion if there's two types out there. Given the mountain of anecdotal evidence to support a Gen2 version with the same designation, I might need to do that anyway. The information I have might be incorrect also, but it was published by one of the better known NV experts around 1985 and their book is regarded as one of the main sources of NV information leading up to Gen3. David |
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Hi Hugh, That is more or less correct, but we're talking about the Gen 3+1 tubes for the same device - These aren't a 3rd gen tube per se, but a Gen3 tube bonded by FO to a Gen1 tube. It's also known as a Hybrid tube. This particular type of tube has higher gains than any Gen3 tube - if there's any light, it will work. Most commonly these tubes are found in the Stinger Night Sight version of the PVS-4 or are used in research due to the high gain, low noise and gating capability. Regards David |
By coincidence I have a new (surplus) MX-9644/UV tube I bought which is at the PO waiting for me to sign for it. It is a ITT tube. I will post some pics of the numbers and the PC to help clear this up some. I have seen photos of the tubes that LL is referring too but, have never seen a Litton MX-9644/UV. I believe you 100% David. I believe it was written in the book you referenced. I just think that he was mistaken as too the labeling of the tube. I also have read it was not a drop in replacement and the focal length was different. If it was not even the same physical size as a MX-9644 it makes sense to me it would be a separate and unique tube. I am sure we will get to the bottom of this.Like you I just want to know without a doubt. 
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Hi Hugh1, From what I know about it, the MX-11620 is a standard Gen3 with a FO inverter. The Gen3+1 can have a gain of around 100,000 - but that's cd/lm/m2 - Approximately 314,000 if you use fl/fc - That's more than three times the gain of the MX-11620 with a better EBI and S/N as well as well as extended IR sensitivity due to the GaAs PC. Gain comparisons are often complicated by the use of two separate units - fl/fc or cd/lm/m2. David |
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Quoted:
By coincidence I have a new (surplus) MX-9644/UV tube I bought which is at the PO waiting for me to sign for it. It is a ITT tube. I will post some pics of the numbers and the PC to help clear this up some. I have seen photos of the tubes that LL is referring too but, have never seen a Litton MX-9644/UV. I believe you 100% David. I believe it was written in the book you referenced. I just think that he was mistaken as too the labeling of the tube. I also have read it was not a drop in replacement and the focal length was different. If it was not even the same physical size as a MX-9644 it makes sense to me it would be a separate and unique tube. I am sure we will get to the bottom of this.Like you I just want to know without a doubt. Thanks for that - that would be really helpful. :) I've often wondered about the focal point issue with the Gen3+1 and the F4844 - If you look at the photocathode of a Gen3 tube, it's below the surface of the glass, but on the FO of the MX9644, it's the surface... We're talking about 2 to 3mm here, not a lot - but you might run out of thread on the focal knob when you re-install it without a different eyepiece assembly. I'm pretty sure the MX-11620 is a drop-in replacement though - but Flex could tell you for certain. He has one. David. |
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OK, here few pics of various cathodes so that you can compare. All tubes are direct drop-in replacements.
MX-9644/UV by NI-TEC 
MX-9644/UV by DBA Electro-Optical Systems (later Litton) 
MX-9644/UV by Varo 
MX-9644/UV by ITT 
Type 6014 (Israel) 
ITT F4845 (USA) 
Ei-SOVA XX2500 (Serbia) 
DEP-Photonis XX2050 (France-Holland) 
Newcon NC107663IF (Canada) 
Model 510-7330-306 Gen3 tube by Litton 
MX-11620/UV by Litton (Gen3 OMNI V) 
MX-11620/UV by Litton (Gen3 OMNI IV) 
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Thanks, Guys... But something's up.
What is that? That Gen3 PC is extended about 1/4"... Based on the pins (and the limited range of movement for the pins due to the PVS-4 design) that's actually a lot closer to the front lenses... Yes it would still probably fit OK, but only just. Could this be one of the 3+1s? There's no need to push a Gen3 out that far. It certainly matches the differences in the early reputed 3+1s. If only there was a pic of the F4844 to compare it to. Nice to notice all of the Gen2's are FO coupled to the PC while all of the Gen3's are typical Gen3's. David |
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