Fero D51 Gen 2 night vision binoculars.
These are a pair of presumed ex Bundeswehr night vision goggles that have had new old stock image intensifier tubes installed, and 3d printed parts added to make the device usable with modern dovetail style mounts.
Originally, these devices were designed to be used with a face mask / cap which the goggles attach to. This allowed them to be worn under a standard issue helmet without modification. The material used for these was brittle, the face mask on this example has some cracks, some of which have been repaired by a previous owner. The same material was used on the external body of the goggles, there is a crack near one of the mounting points for the face mask, as pictured. These flaws do not interfere with the operation of the goggles when using the included 3d printed dovetail adaptor, which allows you to use these goggles with modern dovetail mounts such as the "L4G24". Please note, the dovetail mount and helmet shown in the first image are not included!
These goggles take two standard AA type batteries, which are inserted into a battery compartment on the top of the device. This compartment is also where the dovetail adaptor is installed, it simply slides onto the door of the battery compartment, which is then closed, preventing the adaptor from sliding off. No modification to the device has been made to fit this part.
On the underside of the device, there is a 3 position power switch, which switches between off, on, and on + IR illuminator. Once the switch is moved to either "on" position, the tubes take just under a second to start up. The infrared illuminator is located at the front of the device, between the two objective lenses. I've found it perfect for map reading or spotting animals. Inside each eyepiece, there is an infrared illuminator indicator LED to remind you that the illuminator is emitting. This part is a separate plate that is placed on the back of each image intensifier. I have tested each of them and both are working, though the one on the left side does not illuminate when installed on that side. This should not be an issue, as the right one alone is enough to remind you that the IR illuminator is on. These plates introduce a line at the top and bottom of the image seen through the goggles, that blocks some of the view. I've not found this to have any significant impact when walking around with them on.
On the top of the device, to the side of the battery compartment, is a push button that provides power to the goggles when the power switch is in the on position. The intent of this was so that the goggles could be used as an observation device when not mounted using the face mask, the button would be held when holding the goggles to your eye, and released when you were done with them. A slot in the back of the goggles accepts a pin on the face mask, which holds this button in the "on" position when using it head mounted. A 3d printed part is placed inside here to override this feature so that the goggles work when the face mask is not used.
A carrying strap is usually attached to either side of the goggles so they can be worn around the neck. I have removed this strap, if you'd like me to reinstall it, please message me. It's designed to be removed, it's just a little fiddly.
The lens and image intensifier assemblies are joined to an internal frame, which is surrounded by a polymer outer body which also houses the battery compartment. This frame assembly can be seen in the user manual, as pictured.
The front lens system on these goggles are particularly interesting, as the focus of each lens is linked by a belt so that when the focus of one is changed, the other lens also changes by the same amount. This is particularly useful as you only have to change the focus once for both eyes instead of having to adjust each lens separately.
The diopter adjustment for the eyepieces is done by moving a lever that is protected by a rubber shroud to the rear of the device. This helps prevent accidental movement of the focusing mechanism, and protects it from the elements. The eyepieces also have demist shields fitted, which prevent condensation from forming on the eyepiece lenses. Two spare demist shields are included in the pack of spare parts, and are factory sealed.
The interpupillary distance can be adjusted by simply pushing the eyepieces side to side, each side of the goggles pivots on an internal joint. There is a lever on the underside of the device that, when pushed open, allows the tilt and height of the goggles to be adjusted within the outer shell.
I have installed new old stock image intensifier tubes in this device, I presume they are Harder Digital tubes based on the protective stickers that were covering them. The left tube is clean, though the right one has a zone 2 blemish in the lower left area of the tube, as pictured. I have added an image of the left tube, right tube, then the right tube with the IR illuminator turned on. I have found these to be excellent tubes, with great low light performance and signal to noise ratio. Pictures were taken with no starlight or moonlight on an overcast night.
With new tubes and a modern mounting interface, these goggles are not only an outstanding collector's item but a very capable and handy night vision device.
Sent via Royal Mail Special Delivery 1pm.
Please do not hesitate to contact me for additional information, pictures or videos. More than happy to answer any questions. Cheers!
Set includes
-Fero D51 Night vision goggles
-Metal case
-Soft carrying bag
-Goggle strap
-Daycap
-User manual (German)
-Spare parts (Factory sealed)
-3d printed dovetail adapter
-3d printed power button holder piece