Esp8266 antenna range

Hello. with esp modules that have on board antenna, which orientation should they be to each other to get the best range ,holding the module vertically?
if they are perpendicular to each other and the antenna is omnidirectional, the module with better range send the signal, the other one receives data but for data delivery confirmation, the rx module won't have the same range since it is has it's antenna facing perpendicular

you can burn a sample that prints on serial monitor the RX level then you work with that. RF is very difficult to deal with....
with so many reflections I cannot believe you will see a difference on rotating 1 antenna... that´s why I think you should measure your own scenario behavior

You would think that the orientation of the antennas, for maximum distance, would be the same for each module, if the modules are identical.

Which orientation gives the longest range, on identical modules, could well depend on the specific modules.

Have you carried out any experiments ?

i've got about 150m -200 range with modules oriented to each other as they would lying on a table but i think that the omnidirectional signal that creates that donut would be in this case on a plane perpendicular to the table so in height

The configuration of the folded antenna suggests it will radiate most strongly in the general direction the stepped part points, with a polarisation axial to the long dimension of the larger PCB.

Its weakest signal should be more-or-less in that axial direction, though the folding alters that direction. It is probably weakest toward the other end of the larger PCB. Signal should be very reasonable perpendicular to the PCB.

The Lolin (Wemos) D1 Mini Pro, and the ESP-7 module, have a ceramic antenna onboard. I don't know what difference it would make.

I cannot comment on that particular antenna, but similar ceramic chip antennas are used on some GPSs @ 1575Mhz.

A simple 1/4 wire is a much better performer, 10+dBm better ..... ..........

We used to buy the receiver electronics with a ceramic "patch" antenna on top of the shield for the electronics. And then applied the assembly to a printed circuit board for marine electronics. Apparently very effective antenna.

The ceramic "patch" antennae are quite a different design and of course, receive signals more-or-less perpendicular to the plane of the patch.

The ceramic antenna on the ESP-07 module would be essentially similar to the zig-zag one. In the same manner, it relies on or is affected by the adjacent ground area of the PCB.