PH2LB shack on the internet.

LoRA measuring antenna's - first results

This page was last updated : 11-Mar-20 23:09:21

First results

Below I have added a few sets of indoor test results which I made with this setup.

I have connected the server to my DIY LoRA Antenna which is normally connected to my router and put the client on the workbench in my shack (which is 3 meter below antenna and 1m off center). It's not ideal (because of the radiation pattern DIY LoRA Antenna) but for startes it will give me some information.

First a test base line based on a (not so RF save) 50 Ohm dummyload connected to the client.

Client with 50 Ohm dummyload
---------------------------
SENDRSSI|RECVRSSI
-57|-59
-62|-59
-62|-59
-62|-59
-62|-59
-62|-59
-62|-59
-62|-59
-62|-59
-62|-59
AVGSENDRSSI|AVGRECVRSSI
-61|-59
 

A nice base line for starters (note to my self : buy better dummyload)

Next I connected the antenna which I got with my Lorank8 gateway.

Client with Lorank8 antenna
--------------------------- 
SENDRSSI|RECVRSSI
-41|-43
-47|-44
-47|-44
-47|-43
-47|-44
-46|-43
-47|-44
-47|-44
-46|-43
-45|-42
AVGSENDRSSI|AVGRECVRSSI
-46|-43 
 

So it seams that it preforms better then the dummy load :-)

Next I connected a simple magnetic foot antenna which I got with my  RF1276 Ultra long range LoRA modules.

Client with China antenna
-------------------------
SENDRSSI|RECVRSSI
-38|-38
-42|-38
-42|-38
-42|-38
-41|-38
-42|-38
-42|-38
-42|-38
-42|-38
-43|-38
AVGSENDRSSI|AVGRECVRSSI
-41|-38
 

It seams that that aren't the worst antenna's to buy (better then the original Lorank8 antenna). :-S

Next I connected my new DIY LoRA GP antenna (which should be used in the field as baseline antenna).

Client with Groundplane antenna
-------------------------------
SENDRSSI|RECVRSSI
-32|-32
-36|-33
-33|-33
-36|-33
-36|-32
-36|-33
-36|-32
-36|-33
-36|-32
-36|-33
AVGSENDRSSI|AVGRECVRSSI-35|-32 
 

Wauw that was suprising. It's preforms very well. Even better the commercial antenna's.

Then I connected my new DIY LoRA J-pole antenna

Client with J-pole antenna
--------------------------
SENDRSSI|RECVRSSI
-33|-34
-35|-32
-35|-32
-35|-32
-35|-32
-35|-32
-35|-32
-35|-32
-35|-32
-33|-32
AVGSENDRSSI|AVGRECVRSSI-34|-32 

Even better then all the other antenna's. I expected it to be atleast 1 or 2 points better then the GroundPlane which it was almost. But the J-Pole radiation will have its influence. The test in the field will give more conclusive results. Great experiment.

But there was one antenna really needed to be tested. The updated DIY LoRA antenna (update)

Client with updated antenna
-------------------------- 
SENDRSSI|RECVRSSI
-35|-33
-35|-32
-35|-31
-35|-33
-32|-32
-35|-33
-35|-32
-34|-32
-35|-31
-35|-32
AVGSENDRSSI|AVGRECVRSSI
-34|-32

I expected it to be atleast 2 or 3 points better then the GroundPlane. But it wasn't. Atleast it was as good as the J-pole. The reason would be the radiation angle of these antenna's (Omni Directional HIGH GAIN Dipole : link). The test in the field will give more conclusive results.

Importent note : As you see in the above result theres is every time a difference from 2 or 3 in RSSI between send and recieve. I want to switch the RFM95W LoRA trancievers to see if there is a difference in reception sensitivity (I have used the modules for multiple experiments so maybe I have damaged one). Result of this test will be added to this page.

Next step : going outdoor.

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