Friday Night Lights: Dual Tube Spotlight – RNVG, Sentinels, & ANVS

    For this week’s Friday Night Lights we will take a look at not just one but three dual tube setups. The RNVG, Sentinel and ANVS goggles. They are very similar to each other and actually are evolutions of each other. You can almost think of them as grandparent, parent and offspring.

    ANVS Goggles

    ANVS goggles are one of the lightest binocular dual tube goggles around. Last I checked they were around 17 oz. The only one that beats that is the PVS-31 at 15.5 oz. Part of the reason why they are so light is because they were made for pilots. If you look closely, you will notice there is no battery compartment or IR illuminators. It is a simple no-frills binocular housing. So if it doesn’t have a battery onboard how is it powered? The big horizontal cylinder at the top of the goggle with a shiny ball bearing at either end is how it receives remote power. Just below the ball bearing are two brass contacts. This style of attachment is colloquially called “ball detent”. It is rather different from the old GI spec bayonet horn style or the more desirable dovetail.

    The ball detent works in conjunction with a proprietary helmet mount. The cylinder looking attachment point docks into the mount on the helmet and receives power via a remote battery pack mounted to the back of a helmet. The mount allows the goggle to stow upwards or pivot down for use at night. There is no on/off button. Activation depends on what position the goggles are oriented in relation to the ball detent mount. When stored upwards, power is cut off and the goggles turn off. Bring them down to complete the power circuit ad the ANVS goggles will turn on.

    The ANVS housing is rather simple but it is packed with all the adjustments needed for the individual. For other mounting systems, most of the adjustments such as tilt and forward/rearward positioning, are in the mount itself. Not the case with the ANVS, it is all part of the bridge.

    There is a knob on both sides of the bridge. This is to adjust the pupillary distance (PD) of monoculars. It moves them left and right so the eyepiece is centered in front of each corresponding eye. Just behind the left side knob is a small lever. Throw it up and the goggle tilts downwards. Throw the lever down and the goggle tilts upwards.

    Just below the ball detent is a rectangular plate with lines and numbers. In front of the ball detent is the adjustment wheel to shift the goggles forwards or rearwards in relation to the ball detent.

    The ANVS housing is made of a glass-filled polymer for the sake of weight savings, it is not robust. Take a look underneath and you can see the PD adjustment screw and the wiring that delivers power from the ball detent to each monocular pod.

    At each back corner of the bridge are holes for securing the ANVS goggle to your helmet. I used split rings since it is thinner and wider making it easier to hook helmet bungies to them.

    Sentinel – A Ruggedized ANVS

    For a while, before the proliferation of ruggedized bino NODs, CAG (Combat Applications Group) used ANVS goggles for ground use. As mentioned earlier, the ANVS goggles were not for ground use so they are rather fragile. Even though CAG could get replacements, Chris Adams of Adams Industries decided to upgrade the ANVS goggles for ground use. There were metal jackets that would slip over the fragile polymer bridge but the goggles were still prone to breaking with enough force. So Adams designed and made the Sentinel BNVD (binocular night vision device). It is made of machined Delrin with aluminum reinforcements.

    The Sentinel could still use a ball detent if the user so desired but the ball detent tower sits really tall on top of the thick Sentinel bridge. Also, the Sentinel bridge ditched the tilt and forward adjustments since it will most likely be used in a dovetail mount that has those adjustments built into it.

    The Sentinel housing is made of milled Delrin. The bridge has two aluminum plates that are bolted to the front and back of the bridge. The aluminum/Delrin sandwich is extremely robust.

    Just like the ANVS bridge, the Sentinel bridge has two anchoring points at the rear.

    PD adjustment knobs are mounted on each side just like ANVS. The power knob is forward-facing. Just like a PVS-14, you twist it to turn the goggles on. Pull and twist after the on position to activate the IR illuminator. Keep twisting to turn on the focused illuminator. Yes, the Sentinel has dual IR illuminators, flood and spot.

    A battery compartment was built right into the Sentinel bridge. It is powered by a single CR123. Just below and to either side of the battery cap are the purge screws for each monocular pod.

    Just like the ANVS goggles, the Sentinels have wires underneath the bridge with a centralized PD adjustment screw. As the screw turns, the pods translate left or right depending on which direction you turn the PD knob.

    RNVG – Ruggedized Night Vision Goggle

    RNVG 3/4 view

    The Sentinels were the next step of evolution for the ANVS goggles. Well the RNVG can be considered an evolution of the Sentinel as well. Get ready for a story of intrigue and suspense. Chris Adams of Adams Industries is the creator of the Sentinel housing. The Sentinels were the benchmark for rugged dual tube bino housings. They could take a beating, fall off your helmet hit the ground and keep running. However, Chris Adams did not actually make the Sentinels himself. AB Night Vision helped him reach his dream. In fact Adam Barker (AB of AB Night Vision) had to help him complete Adam’s Sentinel design so it could be machined out of Delrin. AB also tweaked the design a bit like making it compatible with PVS-14 objectives rather than ANVS objectives. PVS-14 glass are completely different from ANVS glass. They are not interchangeable.

    When I bought the Sentinel housing, just the housing, no glass or tubes and I was told there was a 3-month wait. I wait and when it came time to have them shipped I was away for a few days for a friend’s wedding in Hawaii. I did not want $1200 to sit in front of my doorstep. So I asked them to hold onto it and wait until I get back before shipping it out. When I get back Adams had informed me that my housings had gone to a Military contract. So a 3-month wait ended as a 6-month wait. Just last year another company, Asymmetric Solutions, was willing to buy out Adams Industries. In good faith, Asymmetric Solutions appears to have offered refunds to some Adams customers. Last I heard AB Night Vision stopped making Sentinels for Adams.

    Now the RNVG is here. Designed and manufactured by AB Night Vision. It has a lot of similarities to the Sentinel but also takes from AB’s own MOD 3 bino housing design. When the RNVG first came out it used a single AA battery. The aesthetics of the long battery compartment were not well received.

    Photo by Will’s Optics

    Aside from the use of a AA battery, the RNVG is made of milled aluminum rather than Delrin like the Sentinel. This allows for thinner walls and a smaller profile goggle.

    Look how thin the bridge looks on the RNVG.

    Looking at both the Sentinel and RNVG from above you can see how svelte the RNVG is in comparison.

    While the RNVG does look trim and fit, it is actually heavier than the Sentinel and all its bulk.

    Just like the MOD 3 bino housing the RNVG delivers power to each monocular pod via four power strips embedded under the bridge. No exposed wiring like ANVS or Sentinel.

    And below is the bridge from an AB Night Vision MOD3.

    Another departure from the ANVS/Sentinel design is how the monocular pods attach to the bridge. The bridge has an inverted T shaped profile and the monocular pods have corresponding slots that go up and around said T protrusions.

    Rather than a long screw through the middle of the bridge. The RNVG has a short screw and PD knob positioned at the rear of the bridge. Because of this, the loopholes for securing the RNVG are machined into the monocular pods themselves.

    The RNVG only has a single IR illuminator but makes up for it by having a LEMO port for use with a remote battery pack. This was added to the housing when they switched from AA to CR123.

    Just like the Sentinel, the RNVGs have the purge screw positioned on the forward face of the monocular pod tower. Just off to the side is a silver pin. That is the index pin that the image intensifier tube sits against so the tube does not spin inside the housing.

    All the night vision housings I have seen position this pin at 12 o’clock. But AB Night Vision has them situated at 11 and 1 o’clock depending on which side you are looking at.

     

    Final Thoughts On The Evolution Of The RNVG

    The ANVS goggles are great for flying and gentle recreational use. But they are fragile. The Sentinel was a great housing that was overbuilt like a tank. It could take punishment and not much has surpassed it that is until AB Night Vision made their RNVG. Their MOD 3 is a modular goggle system where the monocular pods are quickly detachable. Because of this there is some play between the bridge and monocular pods. When enough vibration the power connections can temporarily lose contact with each other and the tubes will shut off until the connections are re-established. For a long time the Sentinel housing was the most desired binocular housing. That is no longer the case since the DTNVG came out although that housing is more than double the cost. If you want a rugged night vision goggle then the RNVG is now the reigning champ and is what most people are asking for and it is what I see night vision companies making, aside from DTNVG builds.

    Nicholas C

    Steadicam Gun Operator
    Night Vision & Thermal Aficionado
    Flashlight/Laser Enthusiast
    USPSA competitor

    Any questions please email him at [email protected]


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