How to manage docker HOST in HTTP mode (without HTTPS/TLS)

I have a Ubuntu 16 and Docker 17.12.0-ce, this docker host is listening on port 2373.

Now on a Windows machine (at prompt) I set DOCKER_HOST=tcp://ubuntu-dcoker-server:2373 env variable and execute the command docker ps and I get:

error during connect: Get https://ubuntu-dcoker-server:2373/v1.35/containers/json: http: server gave HTTP response to HTTPS client

How can I remote control this docker host without secure it with HTTPS ?

Please take a look in my super user post.