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Mysterious Range Issue ESP-01

PostPosted: Sat Sep 26, 2015 4:48 pm
by derek bernsen
Hi there,
I've programmed my ESP-01 as an standalone AP, and I've done some outdoor line of sight range tests,
I had a maximum range of 730 feet ( about 222.5m) when the module was set on a porch about 4 feet off of the ground.
But here's the weird part:
When I set my ESP-01 on the ground, then range is reduced to a mere 150 feet ( about 45m) or so.
This range reduction occurs both on short grass, and flat road. Zero obstacles in the way.
I tested this with battery positive wire to the four middle pins and to the regular VCC pin, and GND pin to battery ground as it appeared Chuck Lohr did.

CNLohr was able to get 1,200 feet or so with the same module in his tests.
So 4 questions:
1. Why is my range dramatically reduced when the module is on the ground?
2. How can I improve this range?
3. Has anyone done range tests for the ESP-201 using an external antenna?
4. If ESP-201 with external antenna range tests have been done, what is the maximum distance you are getting?

Re: Mysterious Range Issue ESP-01

PostPosted: Sun Sep 27, 2015 7:46 pm
by mrburnette
When I set my ESP-01 on the ground, then range is reduced to a mere 150 feet ( about 45m) or so.
This range reduction occurs both on short grass, and flat road. Zero obstacles in the way.


The -01 has a PCB antenna. If you want something to sit on the ground, you need a rubber-duckie antenna above ground level. The PCB is injecting 50% of the signal directly into the earth.

Range of any RF signal is a complex composite of transmitting antenna orientation, receiving antenna gain/loss and receiver SNR, etc. Plenty of Internet RF 2.4G antenna designs articles if you wish to read-up on subject.

Re: Mysterious Range Issue ESP-01

PostPosted: Sun Sep 27, 2015 9:53 pm
by RichardS
Ground is eating all the signal, that why antenna for TV and RADIO and way up off the ground, the closer to the ground the more it can collide with, also literally the ground attenuates the signal itself, so do many other things, like touching the antenna it de-tunes it among other things.... so antenna distance and position to other things can affect it mostly in a negative way, but it was in some cases help it.... research ground planes :-)

Richard.

Re: Mysterious Range Issue ESP-01

PostPosted: Tue Sep 29, 2015 9:59 am
by derek bernsen
Thanks all, I didn't know that.
I will use an ESP8266 module with a external rubber duck antenna higher off the ground next time.