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Night Vision Opnion on this PVS 14 - morovision enforcer

Re: Opnion on this PVS 14 - morovision enforcer

Looks like a standard ITT PVS-14 enforcer to me. You can buy these lots of places some retailers offer hand picked units but you must pay extra $$$$ other than that they should be the same from about anywhere. About the best plus to these is the 5 year warranty if ever needed. I have a couple of hand picked high spec ITT systems right now and some L3 Filmless systems also of the bunch my favorite is the L3 Filmless it just looks alittle sharper in town and really dark nights to me but the ITT warranty is better and performance is also great so its a trade off.
 
Re: Opnion on this PVS 14 - morovision enforcer

Thanks Phantom. I appreciaete it.
 
Re: Opnion on this PVS 14 - morovision enforcer

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Phantom223</div><div class="ubbcode-body"> Looks like a standard ITT PVS-14 enforcer to me. You can buy these lots of places some retailers offer hand picked units but you must pay extra $$$$ other than that they should be the same from about anywhere. About the best plus to these is the 5 year warranty if ever needed. I have a couple of hand picked high spec ITT systems right now and some L3 Filmless systems also of the bunch my favorite is the L3 Filmless it just looks alittle sharper in town and really dark nights to me but the ITT warranty is better and performance is also great so its a trade off. </div></div>

Is the L3 filmless model more robust than the Pinnacle as far as recoil?
ITT does not reccomend mounting on greater than a 223.
 
Re: Opnion on this PVS 14 - morovision enforcer

Given equal MCP to Photocathode spacing an L3 Un-Filmed tube will be more recoil resistant than an ITT Pinnacle. This is mainly to do with the aspect ratio (channel length to diameter)of the MCP. The MCP used in the L3 Un-Filmed tube has higher aspect ratio than the MCP in the ITT Pinnacle tubes i.e. larger channel diameter (pore size) and longer channel length. This higher aspect ratio in the L3 Un-Filmed tubes results in a thicker MCP than that of the lower aspect ratio MCP used in the ITT Pinnacle tubes. A thicker MCP is a a more rugged MCP and will flex less when subjected to recoil.

The MCP in the L3 Un-Filmed tubes are subjected to lower electromotive forces than those in the ITT Pinnacle tubes. The photo cathode voltage in the L3 Un-Filmed tubes is -400v compared to -600v. This means much less gate induced flexing of the MCP.

 
Re: Opnion on this PVS 14 - morovision enforcer

I think compasscall answered this far better than I could
smile.gif
I can add I don't weapons mount my NV monos much at all it looks real cool weapon mounted but I find a helmet setup/good IR laser far better you get bigger more open FOV for scanning around you, faster shot placement, ability to navigate in the dark . I was placing rounds on a metal disk target at 150 yards Monday night using the 3x adapter snapped on my pvs-14 head mounted and OTAL class 1 IR laser . I like to carry the 3X a focal lens in my pocket and when needed I snap it on the 14 for better range viewing / shooting it works well for me
 
Re: Opnion on this PVS 14 - morovision enforcer

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: compasscall</div><div class="ubbcode-body">Given equal MCP to Photocathode spacing an L3 Un-Filmed tube will be more recoil resistant than an ITT Pinnacle. This is mainly to do with the aspect ratio (channel length to diameter)of the MCP. The MCP used in the L3 Un-Filmed tube has higher aspect ratio than the MCP in the ITT Pinnacle tubes i.e. larger channel diameter (pore size) and longer channel length. This higher aspect ratio in the L3 Un-Filmed tubes results in a thicker MCP than that of the lower aspect ratio MCP used in the ITT Pinnacle tubes. A thicker MCP is a a more rugged MCP and will flex less when subjected to recoil.

The MCP in the L3 Un-Filmed tubes are subjected to lower electromotive forces than those in the ITT Pinnacle tubes. The photo cathode voltage in the L3 Un-Filmed tubes is -400v compared to -600v. This means much less gate induced flexing of the MCP.

</div></div>

Hi Compasscall - great post, but there are other factors at work - and for a given pore size, the aspect ratio is dependent on the thickness of the MCP, not the other way around. BTW, did you manage to get measurements on both MCP thickness metrics? I'd love to know the difference.

I guess the important thing about your post is the assertion that the main cause of recoil damage in tubes is the harmonics of the MCP leading to T0 displacement of the MCP at the point of recoil - a hypothesis we both agree on.

Anyway, the issue of mechanical thickness and electrostatic forces is a complicated one. The force is different, sure, about a third of what a thin-filmed tube is ( coulumb's law isn't it? ) but that assumes equal MCP to PC spacing, which is not quite the same. IIRC, the L3 MCP is closer to the PC and the inverse square law may well eliminate the benefit of the lower force.

In any event, the difference is mostly moot for harmonics. A small kid can push another small kid just as high on a swing as an adult can - it just takes a little longer for them to do it. As long as you don't exceed the point at which the structural integrity of the MCP is compromised, the harmonic swing in both MCPs should be similar.

Except for mass. The thicker MCP has greater mass for a given volume and pore diameter, yet the aspect ratio of the MCP itself is almost identical for both - because the variation in thickness is not likely to be significant. Hence given that distortion is roughly equivalent for both, the factor of recoil is the next item to consider.

Given the higher central mass, the recoil-based deflection should logically be greater in the heavier MCP (inverse square law again) so if what you're saying is correct ( and I fully expect it probably is correct given your access to that kind of information and experience ) then based on what you're saying the L3 should have inferior capability to withstand recoil - due to the way stress is distributed in the MCP.

But there are a few other aspects to this as well - I'll give it some consideration to them over easter and think about the other forces involved and whether they play a part.

Regards
David
 
Re: Opnion on this PVS 14 - morovision enforcer

CJ, The facts regarding aspect ratio and MCP thickness are a matter of public record. It is the aspect ratio that determines MCP thickness not the other way around as your musings suggest.

I don’t agree nor am I asserting that harmonics are the main cause of recoil damage. What is being asserted, is that the thicker MCP used in the L3 Un-Filmed tubes is mechanically more durable MCP than those in the ITT Pinnacle tubes. As already stated, a higher aspect ration (thicker MCP) is more robust (mechanically durable) than compared with one of a lower aspect ratio (thinner MCP) and therefore is more resistant to flexing, whether that flexing be induced mechanically and/or by harmonics.

A thicker MCP of greater mass would require greater mechanical force (recoil) to equivalently deflect as would be required for an MCP of lower mass. Sticking to your analogy of swings, a fat kid on a swing with will require much more force to swing the same distance as would be needed for a skinny kid. A great example of high mass MCP’s being more recoil resistant are the MCP’s in the 25mm tubes used in PVS-4’s etc… These MCP have incredibly high aspect ratios (very thick) and much greater mass than even the old thick 18mm 10 micron MCP’s yet it is this mass that makes them so recoil resistant. This really isn’t all that complicated, thicker MCP’s of higher mass require greater G’s to deflect than those of thinner lower mass MCP’s. So given equal MCP – PC spacing the MCP in an L3 Un-Filmed require greater G-Forces to displace/deflect than the MCP in an ITT Pinnacle.
 
Re: Opnion on this PVS 14 - morovision enforcer

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: compasscall</div><div class="ubbcode-body">CJ, The facts regarding aspect ratio and MCP thickness are a matter of public record. It is the aspect ratio that determines MCP thickness not the other way around as your musings suggest.

I don’t agree nor am I asserting that harmonics are the main cause of recoil damage. What is being asserted, is that the thicker MCP used in the L3 Un-Filmed tubes is mechanically more durable MCP than those in the ITT Pinnacle tubes. As already stated, a higher aspect ration (thicker MCP) is more robust (mechanically durable) than compared with one of a lower aspect ratio (thinner MCP) and therefore is more resistant to flexing, whether that flexing be induced mechanically and/or by harmonics.

A thicker MCP of greater mass would require greater mechanical force (recoil) to equivalently deflect as would be required for an MCP of lower mass. Sticking to your analogy of swings, a fat kid on a swing with will require much more force to swing the same distance as would be needed for a skinny kid. A great example of high mass MCP’s being more recoil resistant are the MCP’s in the 25mm tubes used in PVS-4’s etc… These MCP have incredibly high aspect ratios (very thick) and much greater mass than even the old thick 18mm 10 micron MCP’s yet it is this mass that makes them so recoil resistant. This really isn’t all that complicated, thicker MCP’s of higher mass require greater G’s to deflect than those of thinner lower mass MCP’s. So given equal MCP – PC spacing the MCP in an L3 Un-Filmed require greater G-Forces to displace/deflect than the MCP in an ITT Pinnacle.
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Hi Compasscall,

Statically, the thicker MCP should be stronger. Agreed. Harmonically, it's dependent on the circumstances. More mass will lower the natural frequency of the MCP and allow the recoil to impart more energy to the MCP during the recoil phase of shock transmission. This is just basic physics and highlights the relationship between the natural frequency of the MCP and the half-phase natural frequency of the recoil shock.

DC powered tubes aren't as affected by recoil - hence why tubes of around Omni IV are so robust - the recoil must provide the entire force to the tube statically, which it cannot. Perhaps the autogating isn't the only reason why recoil damage occurs, but all the evidence suggests that it's a significant contributor.

As for the MX9644, that's not really a correct way to look at things. The PC spacing in a MX10160 or MX11769 is about 10 thousandth of an inch (0.010"). The PC spacing in a MX9644 is about 2 inches... That's the real reason that it's not an issue there. There is no physical way for the MCP to touch the photocathode in a MX9644 tube under shock unless it shatters into little pieces.


Regards
David
 
Re: Opnion on this PVS 14 - morovision enforcer

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cj7hawk</div><div class="ubbcode-body">
Hi Compasscall,

Statically, the thicker MCP should be stronger. Agreed. Harmonically, it's dependent on the circumstances. More mass will lower the natural frequency of the MCP and allow the recoil to impart more energy to the MCP during the recoil phase of shock transmission. This is just basic physics and highlights the relationship between the natural frequency of the MCP and the half-phase natural frequency of the recoil shock. </div></div>
<span style="font-style: italic">
I completely agree that change in mass alter natural frequency. Even though more energy is tranferred to an MCP of greater mass it may be that the structure is more than capable of absorbing and dissipating the energy at a much lower frequency. Definitely some need stuff to think about, better than counting the dollars going out the window whilst awake with insomnia. </span>

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cj7hawk</div><div class="ubbcode-body">DC powered tubes aren't as affected by recoil - hence why tubes of around Omni IV are so robust - the recoil must provide the entire force to the tube statically, which it cannot. Perhaps the autogating isn't the only reason why recoil damage occurs, but all the evidence suggests that it's a significant contributor.</div></div>

<span style="font-style: italic">Those standard film tubes are quite something. Had an interesting result the other day while installing a tube. The tube wouldn't slide in and needed a little extra pressure, as it was binding up on some resin inside the housing. Anyway I gave it a loving nudge and suddenly PingggggggRingggggg the energy from the tube smacking the inside of the tube transferred the MCP and it was singing a little song to dissapate. It held a pretty good high note for a good 10 seconds. This was an "A" tube. I'm fairly certain the MCP in those were 6 micron pitch but am unsure of the correlating aspect ratio. Autogating is most definitely a significant factor in all this as it causes the MCP to play footsie with the PC.</span>

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cj7hawk</div><div class="ubbcode-body">As for the MX9644, that's not really a correct way to look at things. The PC spacing in a MX10160 or MX11769 is about 10 thousandth of an inch (0.010"). The PC spacing in a MX9644 is about 2 inches... That's the real reason that it's not an issue there. There is no physical way for the MCP to touch the photocathode in a MX9644 tube under shock unless it shatters into little pieces.</div></div>

<span style="font-style: italic">My bad on this one, I was using the FO cathode Gen III as examples in my mind and was looking at the MCP from one of them as I was typing. Those MCP's are really robust. Not as easy to break while flex testing as are the !8mm thin-filmed ones.

I must reiterate that given an Un-filmed and Pinnicle Thin-filmed with equal PC-MCP spacing, the un-filmed will cope better with energy transfer and subsequent release.
</span>
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cj7hawk</div><div class="ubbcode-body">
Regards
David
</div></div>
 
Re: Opnion on this PVS 14 - morovision enforcer

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: compasscall</div><div class="ubbcode-body">
I must reiterate that given an Un-filmed and Pinnicle Thin-filmed with equal PC-MCP spacing, the un-filmed will cope better with energy transfer and subsequent release.
</div></div>

I know you're suggesting that, but I don't think there's really any quantifiable way to determine if the L3 or the ITT tube is more robust against recoil conditions based on MCP thickness alone. The thicker MCP might make it stronger or might make it weaker. Additional mass is not always a good thing, even with a stronger structure - and from what I can tell, it's quite likely to have a negative effect harmonics-wise.

eg, http://www.youtube.com/watch?v=j-zczJXSxnw

However both tubes should approximately meet the same spec - so people don't really have to figure it out. Thin film tubes such as are found in the Night Enforcer are rated for 5.56 recoil from ITT. As far as I know, Filmless L3 tubes are not. Traditionally, they were rather fragile though I expect L3 has had more than enough time to solve it if it can be solved without compromising the other more desirable performance characteristics of the tube.

But unless L3 come out and say it's rated for 5.56, I wouldn't recommend it -

On the other hand, if L3 come out and say it's fine, I have no reason to question it -

Vic - I know you get tubes from both manufacturers regularly - Are you able to offer any insight into what the L3 factory recommend?

Thanks
David
 
Re: Opnion on this PVS 14 - morovision enforcer

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cj7hawk</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: compasscall</div><div class="ubbcode-body">
I must reiterate that given an Un-filmed and Pinnicle Thin-filmed with equal PC-MCP spacing, the un-filmed will cope better with energy transfer and subsequent release.
</div></div>

I know you're suggesting that, but I don't think there's really any quantifiable way to determine if the L3 or the ITT tube is more robust against recoil conditions based on MCP thickness alone. The thicker MCP might make it stronger or might make it weaker. Additional mass is not always a good thing, even with a stronger structure - and from what I can tell, it's quite likely to have a negative effect harmonics-wise.

eg, http://www.youtube.com/watch?v=j-zczJXSxnw

However both tubes should approximately meet the same spec - so people don't really have to figure it out. Thin film tubes such as are found in the Night Enforcer are rated for 5.56 recoil from ITT. As far as I know, Filmless L3 tubes are not. Traditionally, they were rather fragile though I expect L3 has had more than enough time to solve it if it can be solved without compromising the other more desirable performance characteristics of the tube.

But unless L3 come out and say it's rated for 5.56, I wouldn't recommend it -

On the other hand, if L3 come out and say it's fine, I have no reason to question it -

Vic - <span style="font-weight: bold">I know you get tubes from both manufacturers regularly - Are you able to offer any insight into what the L3 factory recommend?
</span>
Thanks
David </div></div>

PVS-14 speaking only, BOTH manufactures ITT and L3 recommend and always have that PVS-14's were not ever built for more than 5.56, nor were they ever tested above this due to housing construction and other considerations.

The original intent of the AN/Mil 14 contracts way back when was always a head mounted system first and for special designated marksmen role capability of a M4 Carbine type weapon. This also talked in the ITT Patent on the 14 on the appropriate weapon mount (See Below).

This is the main reason we see that somewhat outdated Mil-Spec type weapon mount STILL included in the AN kits out to the Mil as it was called out for early on. We hope that will change one day with our TM-14 especially with thousands more Aimpoint 3x magnifiers going out every year...Testing continues. ;-)

As for tubes, ITT rates theirs for 500g's and below while they survive quite well on the FLIR line of clip-ons due their shock mitigation patented system.

As for L3, they never have stated officially to us about their filmed tubes except to say their line of clip-ons have no issue up to .308's and I agree wholeheartedly. I've shot the CNVD-LR on a 300 win mag as well.

Now as for their FILMLLESS they have always told us no weapon mounting ever, these are for head mounted systems. With that said, we see weapon systems out there warrantied for shock so it comes down to what the dealer warranty is.

We tend to shy on the side of caution nowadays and just go by what the actual manufactures tell us. We've seen enough blown up tubes on both sides of the fence as we all know there is NO magic tube, they can and DO fail.

Hope that helps.

Vic