Night Vision A few solutions for running Simrad PVS-9 KN203FAB’s on larger optics

redneckbmxer24

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  • Jan 15, 2005
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    I get a lot of PM’s from guys asking how to go about using Simrads with larger optics. Here’s a few solutions I have found:

    1. Remove objective sunshade. This gains clearance and also allows the clip on to be used with optics that have larger than 42mm objectives. By removing this piece which I have found not to be required and the combination of the Spuhr A-0018 rail on a Spuhr mount (slightly longer than Badger) allows the unit to be used with most scopes. The sunshade removes by backing out the two small Allen screws located on each side.

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    2. Machine off the portion of the frame that supports the sunshade. This gains an extra .320” of clearance by itself. The only downside to this modification is that it’s permanent and you will no longer be able to mount the sunshade.

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    3. Extension pieces for the mount. The extensions shown below are actually what the KN253 units use the mount to its body since it doesn’t use the same frame system as the KN203. These work with the KN203’s extending the mounting significantly. It does change the mounting height however but you can bolt the mount either to the top or bottom so you have the option to raise or lower the unit for whichever works best for your application. I see two potential issues with this however, the first being sourcing the pieces themselves which I’m working on having some made which should solve the supply issue. The second is that it increases the cantilever of the unit itself putting more stress on the mounts. I have no doubt that the unit and Simrad mounts can take it, my concern would be exceeding what the Spuhr rings are capable of. I will be emailing Spuhr to get their thoughts. Pending response Badger may be an alternative solution since the steel may prove beneficial in this circumstance. Spuhr does make a very long replacement ring cap however for a different version of a Simrad mount so I think there’s a good probability that they will respond that the mount will handle the load.

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    The KN253's with just the sunshade removed also allow about .250" longer mounting length with the KN203 with it's sunshade removed.

    For those looking to use shorter/stubby objective scopes with short front tube mounting lengths the "old style" Simrad mount may prove beneficial as the dovetail mounting length is about .110" shorter which may aid being able to get the mount on the dovetail if the clearance of the front of the dovetail to the objective bell is tighter.



    At the end of the day the Simrads are amazing performing units and they will work for most applications but they aren't quite as simple as just having a continuous picatinny rail or EFR and 1.5" mounts like the more standard clip ons. They do however cost 1/3 of what the lowest priced comparable inline clip on does which buys a lot of mounts, or a second unit and some mounts. They do have an advantage however if you have a platform which doesn't have a continuos rail or an EFR. If you can use Badger or Spuhr mounts on your application, they you can run them.

     

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    GOOD info, and thanks for posting it up .
    The SIMRAD info is harder to dig-up for tuning your Rig-Cap setup's to fly with your optics you choose to run .

    ( myself ) when I 1st got my SIMRAD i had high hopes of popping on my longer tube body usoptics, but soon had that dream crushed...LOL . but I quickly learned to proper scope match to the SIMRAD units . Larger scope bodies with bigger Obj. lens are hit and miss for a compatible match with SIMRAD .
    --
    I hunted with both modular rail clip-on and SIMRAD unit . SIMRAD is not as easy/versatile as modular rail Clip-ons . but I still like the SIMRAD I have, and it does offer Primo performance as far as quality of image goes, with easy popping the power up past 10x and 12x for magnification on the average nights .
    Both rail clip-on and SIMRAD clip-on have weight and mass to deal with and once you get past the Ring-Cap set-ups on your rifles optics . the Pro and Con's past that point seem like kind of a toss-up . the SIMRAD is top-heavy on a rifle sitting high . But the modular rail (in front of Obj.) clip-on is front-end nose heavy on a rifle for off-hand shots .
    But the SIMRAD does offer you ability to manual adjust your Collimation with it's Prism lens system . And the whole unit is not sitting in-front of your day scope Obj. so the On-Off switch and focus control knob are little closer to the hands .
    .
     
    Thank.. will keep an eyeout for info .
    Was a tight squeeze and a NoGo getting the unit frame up and over the Obj. to slip-in the Dove-tail . Looked like a 'height & length' issue with uso .
    . The uso that I have is only a 44mm Obj. ,but the length of the Obj. Bell-body tube is length is the NoGo .

    Not like I need a huge amount of magnification but It would be great and would help run the simrad on my Bolt rifle set-up and the Ret. subtensions for holdovers would be handy . and the uso does go down to 3.8x on the low-end .
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    Great timing, i was just thinking about this. Was thinking of trying a simrad and was thinking of mating it with a 4-16x42 atacr or a Kahles k624i. Spose i might have issues running with the kahles?
     
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    Great timing, i was just thinking about this. Was thinking of trying a simrad and was thinking of mating it with a 4-16x42 atacr or a Kahles k624i. Spose i might have issues running with the kahles?

    I've run them with the 4-16 ATACR and it works flawlessly. There's a guy running one on a Kahles 6-24 with the Badger rings and mount and all he had to do was remove the sunshade. The Kahles doesn't have an overly long objective so it's not an issue.
     
    Thank.. will keep an eyeout for info .
    Was a tight squeeze and a NoGo getting the unit frame up and over the Obj. to slip-in the Dove-tail . Looked like a 'height & length' issue with uso .
    . The uso that I have is only a 44mm Obj. ,but the length of the Obj. Bell-body tube is length is the NoGo .

    Not like I need a huge amount of magnification but It would be great and would help run the simrad on my Bolt rifle set-up and the Ret. subtensions for holdovers would be handy . and the uso does go down to 3.8x on the low-end .
    .

    Send me some pics of the clearance on the USO if you can. The way the extensions pieces as shown in the bottom picture work will get you some slight height clearance too. They mount onto the frame of the KN203 where the mount would bolt and then the mount can bolt to either on the top or the bottom of the extensions either raising or lowering the main unit by about .1". The extensions also extend the mounting length by .900".
     
    Instead of modifying the sunshade mount, you can just take it off, as all it does it support the sunshade. Two allen head bolts and its out. This works on the 203's.
     
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    So I got schooled in Simrads. My 253, that is marked as a 203, is indeed a 253, so what I posted above will not work for 203's..... Not sure how or why, but it looks legit, and it still lights up like dammit......... Now I want a 203 too.......
     
    So I got schooled in Simrads. My 253, that is marked as a 203, is indeed a 253, so what I posted above will not work for 203's..... Not sure how or why, but it looks legit, and it still lights up like dammit......... Now I want a 203 too.......
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    marked wromg ? ( 203 is larger Obj. than 253 ) How big is your pvs9 ?
    You might have the 203 . Because my 203 has those 2 small allen head holding on the sunshade, and I have taken off and put back on also .
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    Really Weird FAB would mark wrong ?
    but your FAB tag looks like it on the bottom of the pvs-9 . My KN-203 FAB label is on the top of the unit .
    Your fins on the focus ring look like bigger like 253, and your bracket frame under the unit looks cut-off shorter length like a 253 .
    The kn-203 Obj. lens Is roughly about ( 4 1/8" ) in Diam. . So your 253 should be much smaller Obj. and lighter weight also.
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