The BIG and SMALL ANTENNA topic part 1

So we have two requirements:

  1. measure impedance and so get an indication of frequency (return loss (VSWR))
  2. Antenna efficiency measurements

both have different requirements for the environment :slight_smile:

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  1. cable loss measurement (bring your cable too :wink: )
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So how did this work out?
I have one the same as this on the way and assembled the hardware to put it on a 5m pole over my house today. I won’t go back on the roof until I have this delivered but interested to know what you discovered testing. Go on, tell us all?

very happy with it and gonna use it as my ‘main’ antenna :wink:

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Hi Laurens, have you considered using ARRL course materials? I am sure they have what you’re looking for, and probably happy to support. ARRL, the national association for Amateur Radio, hq@arrl.org

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Tracking says that my antenna is due for delivery today but I am thinking I should admire it’s elegance indoors for a day or two. If I climb on the roof to install it today this could be my last post to the thread; 12m high sea swell and 121kmh winds!

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That said, I am looking forward to the next round of testing and that reminds me; have we a tutorial or example of how I might downlink to an end device and use a character to call pre defined routines stored within (LMIC & Ardyino IDE)?

Thx, G

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I tested the other way…
send the same packets to the same application with the same node but with the different antenna’s.
then I compare the received gw signals on the console (application data)

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x505

this one just arrived :sunglasses:

x506
my neighbour asked if I was making bombs … :rofl:

the 2 dbi puck antenna seems to work fine (just reached 13 km)

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I have one of these which I have yet to test. I am not sure how much signal is attenuated when the node is at ground level, consider an arable agri application for example. I can imagine this antenna placed on a post to gain some elevation if only a couple of metres. My lack of RF or Antenna knowledge may be very obvious but would this unit benefit from some sort of ground plane, if it was mounted on a metal sheet/plate or even a mesh? If so, what would it ideally look like in size and shape?

no problemo I think :wink:

Well that didn’t take long…

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The local pigeons have decided they like their new 3dBi perch!

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LOL :sunglasses:

x516a

11 dbi and 13 dbi … :roll_eyes:

x516b

nice story from Garry https://www.thethingsnetwork.org/community/dublin/post/a-popular-gateway-upgrade

Thanks BoRRoZ! Finally got the gateway and outdoor antenna permanently installed so the antenna experts here may advise about how effective the shield on the rear of my TV’s array antenna will be for blocking LoRa to my new 3dBi antenna? Should I lower the array below my LoRa antenna for better omni-directional?

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Does this antenna/gateway combo work? Well yes, I have received packets from just over 15km but from high ground, it is not totally flat around my house. I used my home made 1/4 wave ground plane from the @lex_ph2lb design on a Pro-Mini node with RFM95W radio but didn’t hang around long enough to try other antennas on my node. I have however seen over 5km with one of those tiny 50mm long sma antennas so next testing is to see how close to the ground I can reliably place my node without attenuating too much RF energy.

Garry

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I think its always better when an omnidirectional antenna, like the one you have installed, is ‘free’ all around so no reflection/blocking/attenuation ect. … but to climb on the roof immediate… take your time to expiriment a bit and watch your console / application

We’ve been using these $30 antennas and they work fine. We get 6 miles distance. Here is a picture of a gateway and antenna installed on the roof of a local winery in Temecula, California.IMG_3838

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I am curious to know if you have to be careful with node placement, specifically height over ground? One application we’re lookig at has the nodes on or effectively just below the ground! Not much data yet.
Thx, G

antenna should be above ground with the sensors underground if you need some distance.

sensorglobe_agriculture_iot_1

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The city I live in has LoRa sensors in manholes. Since the manhole can be in the middle of the street, the antenna needs to be placed underground. They have limited the distance to nearest gateway to 500m, and they report that works.

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