ARGUS 31 Installation Instruction

We are excited to announce a significant addition to our night vision lineup – the Argus 31. This model stands as a high-caliber alternative to the renowned PVS-31, embodying top-tier features in night vision technology.

The Argus 31 sets itself apart with exceptional glass quality, offering unparalleled clarity and precision in low-light conditions. Crafted with materials that mirror those used in the PVS-31, it ensures durability and a familiar feel to users. The slightly heavier weight of the Argus 31 is a result of internal modifications designed to enhance compatibility with a variety of tube types, broadening its functionality and adaptability.

For professionals and night vision enthusiasts, the Argus 31 is more than just an alternative; it's a testament to optical excellence and versatile design. In the following section, we'll guide you through the installation process, ensuring you get the most out of your Argus 31 experience.





Unpacking the Argus 31 Kit: A Look at the Included Components

With the Argus 31, you'll receive an array of components in the kit, each designed to optimize your night vision experience. Let's explore what's included:

  1. The Housing: This is the central unit of your Argus 31, meticulously crafted for durability and ergonomic ease, ensuring a comfortable and efficient operation in various conditions.

  2. The USBP (Universal Stroke Battery Pack): A key power source for your device, this battery pack is designed for longevity and consistent performance, keeping your night vision operational for extended periods.

  3. The Fischer Cable: Essential for reliable power and data connectivity, this cable ensures uninterrupted and smooth functionality of your device.

  4. Collimation Adapter: This tool is specifically used for collimating the image axis of the two tubes, vital for achieving clear and aligned imagery in your binocular setup.

  5. The Argus EGAC (Enhanced Gain Adjustment Control): Offering the ability to fine-tune the gain, this component is crucial for adjusting image brightness and ensuring clarity in varying light conditions.

  6. The Soft Case: Protect your Argus 31 with this durable soft case, designed to shield your device from the elements and transport it safely.

  7. Bikini Lens Cover: A simple yet effective cover to protect the lenses of your Argus 31 from dust, scratches, and other potential damage when not in use.

  8. Installation Tool: A tool specifically included to assist with the installation and adjustment of your Argus 31, ensuring a smooth setup process.

  9. Argus Light Weight Night Vision Mount (LWNVM A4): A critical addition to the kit, this mount is designed for lightweight and stable attachment of your night vision device, enhancing overall usability and comfort.

  10. Eyecup: An essential component for comfortable viewing, the eyecup helps to block out extraneous light and improve visual clarity, enhancing the overall user experience.
  11. Light Pipe: A novel addition designed to attach to the tube, serving as an indicator. This feature enhances the functionality of the device, providing a visual cue for operational status.
  12. Retention Ring: This component is designed to attach a retention system to the helmet, ensuring secure and stable mounting of your night vision device.

Each component in this kit complements the Argus 31, contributing to a full and satisfying night vision experience. In the next section, we'll guide you through the steps of installing and utilizing these components effectively.









Installation Preparation for Argus 31

Before you start the installation process, it’s important to gather all necessary tools and materials. This guide will take you through the steps to properly install key components of the Argus 31.



Step 1: Attaching the Light Pipe to the Tube

The L-shaped light pipe has two ends – a longer end with a slope and a shorter end.



  1. Identify Ends: The sloped end is designed to sit on the phosphor screen side of the tube. The shorter end should align with the center line of the PSU (tube shell), where the tube notch is located.

  2. Adhesive Application: Use epoxy, a glue gun, or another adhesive you’re comfortable with. Apply the glue to the surface of the tube where the light pipe will be attached.

  3. Attachment: Hold the light pipe firmly against the tube until the adhesive sets.

    • Note: If you prefer not to have a permanent attachment, using a glue gun or a lower-strength glue is recommended.



Optional Step 2: Installation of the ARGUS EGAC

This step is optional and should be followed if you wish to adjust the gain control. It is divided into two sections based on the type of tube – L3 tubes with bird cage plug and ITT/Elbit tubes with EGAC soldered.

Section 1: L3 Tubes with Bird Cage Plug

  1. Accessing the EGAC: Gently lift the label slightly to access the standard MX-11769 EGAC.
  2. Replacing the EGAC: Unplug the standard EGAC and replace it with the new Argus EGAC.

Here is a result should look like:


Section 2: ITT/Elbit Tubes

  1. Desoldering: Carefully desolder the birdcage on the Argus EGAC. Also, desolder the standard MX-11769 EGAC from the tube.
  2. Soldering the New EGAC: Solder the Argus EGAC into place on the tube.

Here is a result:

(Credit to: Lithos Tactical Concepts)

WARNING: By doing these modification to the tube, you may end up get the tube warranties avoided!



Optional Step 3: Soldering Pogo Pins and Modifying the Board for Manual Gain Control

If you choose to proceed with Optional Step 2 for adjusting the gain control, there’s an additional step to ensure the manual gain control functions correctly.

Soldering Pogo Pins to the Bridge Board

  1. Identify Location: Locate the designated points on the bridge board where the pogo pins need to be attached.
    1. For Elbit/ITT and L3 tubes where the Argus EGAC were in use, you will need to solder POGO pins to P2 and P3
    2. For Photonis, Katod, or NNVT with 3 pins, you only need to solder one POGO pin to P5
  2. Soldering Pogo Pins: Carefully solder pogo pins onto these points. Ensure a secure and precise soldering job to maintain connectivity and functionality.

Modifying the Board for Manual Gain Control (L3 and Elbit/ITT ONLY!)

  1. Locating R2: Identify the resistor labeled R2 on the board. This resistor needs to be desoldered for the manual gain control to operate effectively.
  2. Desoldering R2: Carefully desolder the R2 resistor from the board. This step is crucial as it activates the manual gain control feature.

Important Notes:

  • These modifications require precision and a good understanding of soldering techniques. If you are not experienced with soldering or electronic modifications, it is highly recommended to seek assistance from a professional.
  • Remember that modifying electronic components can be delicate work. Ensure you have a steady hand and the right tools for the job.
  • By completing this step, you enhance the functionality of your Argus 31, providing more control and customization to suit your specific needs.

By following these steps, you can successfully enhance the manual gain control of your Argus 31. As always, if you encounter any difficulties or uncertainties, do not hesitate to reach out for professional assistance or contact our support team for additional guidance.











Installation Process for Argus 31

Now that you're prepared, let's begin the installation process for your Argus 31. This step-by-step guide will help you through each stage of the setup.

Step 1: Removing the Screws from the Pods

  1. Locate the Screws: Identify all the screws on the pods of the bridge.
  2. Unscrew: Use an appropriate screwdriver to carefully remove all the screws.
  3. Detach the Pods: Once the screws are removed, you can gently detach the pods from the bridge.


Step 2: Loosening the Objective Lens Clamp Screw

  1. Locate the Screw: Find the screw on the objective lens clamp.
  2. Loosen the Screw: Using the right tool, loosen this screw. Do not completely remove it, just loosen enough to free the objective lens.
  3. Rotate Off the Objective Lens: Gently rotate and remove the objective lens from the objective lens adapter.


Step 3: Loosening the Retainer Ring of the Objective Lens Adapter

  1. Using the Installation Tool: Take the installation tool provided in your kit.
  2. Loosen the Retainer Ring: Insert the tool into the slots of the retainer ring and turn it to loosen. This ring holds the objective lens adapter in place.
  3. Remove the Objective Lens Adapter: Once the retainer ring is loosened, you can remove the objective lens adapter from the housing.



  • Handle all parts with care to avoid any damage.
  • Ensure you have a clean, organized workspace to keep all removed parts safe and easily accessible for reassembly.
  • Keep the screws and small components in a secure place to prevent them from getting lost.



Step 4: Adjusting the Diopter in the Empty Pod


Setting Up the Empty Pod

Once you have completed Step 3, you will have an empty pod, ready for the next stage of installation.

Adjusting the Diopter

  1. Locating the Tube Retainer Ring: Look through the objective side of the pod. You will find a tube retainer ring on the ocular side.

  2. Diopter Adjustment: Rotate this retainer ring clockwise or counterclockwise. This adjustment is the only way to modify the diopter as the PVS-31A system doesn't have an external diopter adjustment. It's crucial to set this correctly to avoid eye strain. The PVS-31A typically has a -0.5 diopter setting, in addition to the standard -0.5 diopter piece.

  3. Important Reminder: It's essential to align the trench of the housing with one of the notches on the retainer tube. This gap is specifically designed for the light pipe to pass through and be properly seated.


Methods to Set Diopter Correctly

  1. Caliper Method:

    • Measure the distance from the surface of the objective side of the pod to the step of the retainer ring using a caliper.
    • A distance of approximately 40 millimeters corresponds to a -0.5 diopter value. While not absolutely accurate due to varying tolerances, this is the simplest installation method.
  2. Lightroom Trick:

    • Use a camera app like Lightroom that can read the current focus value.
    • Position a vision test paper exactly 66 inches from your phone camera. Record the focus value at this distance, as it approximates a -0.5 diopter reading.
    • Reassemble the housing with the objective lens and turn on the system. If you are not sure how, Refer to STEP 5 and STEP 6 for installation instruction
    • Focus on the vision test paper as clearly as possible and check the focus value through the system with the camera app.
    • If the values match, the diopter is close to -0.5. Otherwise, further iteration may be needed. Note that phone model differences can introduce some error, but this method helps align diopters closely between pods, reducing eye strain.
  3. Dioptron Method:

    • A dioptron is a tool specifically for measuring the diopter of optical instruments, offering the most accurate readings.
    • Although more expensive and harder to find, we can pre-order one for you. This tool is highly recommended for dealers with multiple build projects.
    • Iterative adjustments are needed for precise diopter setting.




*****Quick Review for Diopter Adjustment Iteration*****


Steps for the Evaluation:

  1. Adjust the Tube Retainer Ring: Adjust the diopter by rotate this ring by hand.

  2. Drop the Tube in the Pod: Slide the tube into the pod, make sure the orientation is correct and the tube is fully seated.

  3. Assemble the Objective Lens, the Adapter and the Retainer to the Pod: refer to the next section for detailed instructions, if you not sure how.

  4. Connect the Pod to the Bridge: It's time for power up. Be caution with the open side of your pod, Don't drop your tube!
  5. Focus the Objective Lens First: You will need the objective lens to set into a correct focus, to get the read of the ocular.

  6. Check the diopter with Pod, one by one: Look through the lenses one by one to check the diopter. You may need camera app or dioptron to get a more accurate and fair value.

  7. Redo Step 1-6 in this section if the diopter does not meet the desirable setting: Start over if the diopter is off, or have difference between both eyes.


Importance of This Trick:

By following these steps and choosing the method that works best for you, you can ensure the diopter is set correctly for optimal viewing and minimal eye strain. Each method has its pros and cons, so consider your resources and preferences when choosing. Dealers or those working on multiple builds might find investing in a dioptron most beneficial for accuracy and efficiency.






Step 5: Inserting the Tube into the Housing

After ensuring the correct positioning of the tube retainer, the next step is to insert the tube into the housing. It's important to handle the tube with care and ensure it is clean before proceeding.

Cleaning the Tube

  1. Clean Both Sides: Gently clean both sides of the tube. Make sure there are no fingerprints, dust, or smudges on the surface of the tube. Use a soft, lint-free cloth and, if necessary, a mild, non-abrasive cleaner suitable for optical surfaces.

Inserting the Tube

  1. Prepare the Housing: Ensure the housing is ready and the retainer is set in the correct position.

  2. Slide the Tube: Carefully slide the tube into the housing. Do this gently and steadily to avoid any damage to the tube or the housing.

  3. Ensure Proper Fit: Make sure the tube fits snugly into place and is properly aligned within the housing.


  • This step requires a steady hand and attention to detail. The tube is a delicate component and should be handled with the utmost care.
  • Proper alignment and fitting of the tube are crucial for the optimal performance of your night vision device.

Once the tube is securely and correctly positioned within the housing, you're ready to move on to the next step in the installation process. Remember, taking your time and handling each component with care will result in a more successful and satisfying setup of your Argus 31.




Step 6: Collimation Process

Collimation is arguably the most intricate part of setting up your Argus 31. The kit includes two types of objective lens adapters, each serving a different purpose.

Understand Two Types of Objective Lens Adapters

  1. Standard Adapter: This adapter does not have collimation capabilities. It's suitable for easier installation, especially if the collimation outcome is acceptable without adjustment.
  2. Collimation-Capable Adapter: This is a two-piece assembly with enhanced features for collimation. It consists of:
    • Base Plate with Lotus Shape Slot: The center slot is designed in a lotus shape.
    • Objective Lens Adapter with Matching Base: Fits into the lotus shape slot of the base plate. The eccentric, threaded structure in the middle, holding the objective lens, allows slight adjustment of the image center by installing it in different orientations.



Installation Procedure:

  1. For the Standard Adapter:

    • Attach the adapter to the photocathode side of the tube, ensuring the notch is correctly aligned.
    • Secure the adapter in place using the retainer ring and the installation tool.
    • Screw the objective lens onto the adapter.
  2. For the Collimation-Capable Adapter:

    • Install the base plate first, making sure the notch is aligned properly.
    • Attach the objective lens adapter onto the base plate.
    • Secure everything with the retainer ring, using the installation tool for a tight fit.
    • Finally, attach the objective lens.


The Collimation Procedure (Only work with Collimation-Capable Adapter)

  1. Understanding Adapter Orientation: The orientation of the objective lens adapter in the pod directly affects the collimation. By rotating and reinstalling the adapter in different positions, you can alter the collimation to achieve the desired alignment.

  2. Reinstalling with Different Orientations: Carefully remove and reinstall the adapter in various orientations to adjust the collimation. This process may require several iterations to reach the precise collimation needed.

  3. Marking for Reference: To keep track of the adapter's orientation, mark one edge of the objective lens adapter as a reference point. Alternatively, you can use the mold injection hole mark on the base of the adapter for this purpose.

  4. Tightening the Retainer Ring: After adjusting the orientation, ensure that the retainer ring is tightly secured before measuring the collimation value. It's important to note that collimation can vary between a loose and tightened state of the retainer ring, so final readings should be taken with the ring securely fastened.

Important Notes

  • Be Organized: It would be hard to keep on track of the record of orientation and collimation status for users who don't have Hoffman or tons of collimation experience before. We will publish another blog post to introduce a way to record the collimation status for you at home. Stay tuned
  • Patience is Key: The process of adjusting and testing for collimation can be time-consuming and requires patience. Each change in orientation might result in a minor but significant adjustment in collimation.
  • Accuracy Matters: Ensure that your markings and reference points are precise. Consistency in your reference will aid in accurately determining the best orientation for optimal collimation.
  • Final Check: Once you believe you have achieved the correct collimation, do a final check with the retainer ring fully tightened to confirm the accuracy of your adjustments.


Successfully completing the collimation will significantly enhance the user experience with the Argus 31 systems, making this meticulous process well worth the effort. Remember, careful and patient adjustments will lead to optimal performance of your night vision device.


Optional Step 7: Setting the Infinity Focus Stop

An optional but recommended step in setting up your Argus 31 is to adjust the infinity focus stop. This ensures that your device can quickly and accurately return to a default focus setting, typically set at infinity for optimal clarity in most viewing scenarios.

Process for Setting the Infinity Focus Stop

  1. Locating the Focus Point:

    • Begin by finding the infinity focus point of your device. This is typically done by focusing on a distant object until it appears sharp and clear.
    • Once you have the focus set to infinity, keep the device in this position for the next steps.
  2. Placing the Objective Lens Clamp:

    • With the focus set, position the objective lens clamp in such a way that the pin is aligned with the focus stopper. This alignment is crucial as it determines the point at which the device will stop when rotated back to infinity focus.
  3. Securing the Clamp:

    • Once the clamp is correctly positioned, securely screw it tight. This will fix the infinity focus stop in the correct position.


Optional Step 8: Nitrogen Purge

Vacuum the Housing to -20 kPa and fill nitrogen to 3PSI. Iterate 10 times to replace the air in the housing with Nitrogen.



With the completion of these installation steps, including the optional adjustments for collimation and infinity focus stop, your Argus 31 is now fully set up and ready for use.

A Few Final Tips:

  • Review All Steps: It's a good idea to go over all the steps once more to ensure everything is assembled correctly and securely.
  • Test Your Device: Before heading into the field, test your device in a safe and controlled environment to familiarize yourself with its functionality and performance.
  • Handle with Care: Remember that night vision devices are sensitive and require careful handling and maintenance. Store your device properly when not in use.

Need Further Assistance?

If you encounter any issues or have questions about your Argus 31, please don't hesitate to reach out for support. We're here to help ensure you get the best experience from your night vision equipment.

Enjoy Your Enhanced Night Vision Experience

We hope this guide has been helpful in setting up your Argus 31. Enjoy the clarity and precision it brings to your night-time observations and operations. Your feedback is valuable to us, so feel free to share your experiences and insights.

Thank you for choosing the Argus 31, and we wish you many successful ventures with your new night vision device.