Go to the main menu. In server browser find an empty server for the map River Somme.
Use filters to choose the map and slots. Join one of the Conquest servers and follow the next steps.

Find the Device here marked on the map.

Better to use a tank equipped with Mortar and destroy the ground here. I found it hard to destroy with Assault and Support explosives and it takes much more time. (Could be easier and faster with friends).

(Update): Based on the other player's experience, limpet charge works better for digging up the ground. Try limpets first.


After well digging up, go and check if all buttons in the picture are visible and available to interact with. There are 5 button-lamps and a key, beneath one of the upper little lamps which you need to use to send each Morse number. (Send key is not visible in my screenshot but I could interact with it).

(5 lamps)

(Send key)

Now go prone and interact with the lamps to turn them on and off to make codes.

First set of the codes:
0 : -----
6 : -....
2 : ..---
7 : --...

Use the picture below to perform the codes. Dash (-) means Turned off lamp and Dot (.) means Turned on lamps (Picture from Google Images).

Be careful!: You need to press the send key for each number you make with Morse codes.
After sending the codes, Follow to the next step.

Deploy with a tank and head over to village
(The red circle here is in wrong place. Go to the one in the wheat farm. Sorry for the mistake and thank you SeaBanananers).

This is the house
Destroy its chimney with the tank or your own explosives

Use the tank making a path to climb the house and reach the chimney

In the chimney there is a wheel-shaped button which will be available to interact after sending the first Morse code. (In some cases the wheel could be invisible. Try to destroy the chimney with more explosives or restart the server if it doesn't work).

Prone near the chimney and press the button (It may take a while). After a second you hear a strange sound. Now get back to the Morse machine.

Warning! (Thank you SeaBanananers)
If you are using tank to climb to house, make sure not to damage the house and chimney too much, otherwise the wheel may disappear.

Go back to the device. All the buttons should be green like the screenshot below:

Send the other set of codes:
0 : -----
3 : ...--
2 : ..---
2 : ..---
2 : ..---
1 : .----
1 : .----
0 : -----

After sending the codes, the lamps go red with another strange sound, showing that you have done all the steps correctly and claimed you reward.

Now it is time to check you dog tag!

From the main menu, in customization tab, choose Soldier / Dog tags / Back / Progression.
Here is your dog tag; Angel Sighting

All of the screenshots are provided by myself in the game.
I don't know the story behind this secret, but found it funny to achieve.
If you enjoyed the review, please support me with your Likes or Steam Points. It makes me happy and motivated to go on with further guides in the game.
If you have any question, problem or additional information, I would be happy to hear it in the comments section.