From b7352f76c27d81c18bfba96c338609a42d6efe1a Mon Sep 17 00:00:00 2001 From: apt105 <73254487+apt105@users.noreply.github.com> Date: Sun, 9 May 2021 15:03:35 +0100 Subject: [PATCH] Small fixes --- website/docs/hardware/antenna/antenna.md | 2 +- website/docs/hardware/antenna/non-aerial.md | 4 ++-- website/docs/hardware/antenna/resources.md | 2 ++ website/docs/hardware/antenna/testing.md | 4 +++- 4 files changed, 8 insertions(+), 4 deletions(-) diff --git a/website/docs/hardware/antenna/antenna.md b/website/docs/hardware/antenna/antenna.md index e1b7c7f9..4398adfb 100644 --- a/website/docs/hardware/antenna/antenna.md +++ b/website/docs/hardware/antenna/antenna.md @@ -1,7 +1,7 @@ --- id: antenna title: Antennas -sidebar_label: Antennas +sidebar_label: Overview slug: /hardware/antenna --- diff --git a/website/docs/hardware/antenna/non-aerial.md b/website/docs/hardware/antenna/non-aerial.md index 5d209b74..299d784f 100644 --- a/website/docs/hardware/antenna/non-aerial.md +++ b/website/docs/hardware/antenna/non-aerial.md @@ -5,7 +5,7 @@ sidebar_label: Non-aerial factors slug: /hardware/non-aerial --- -Unless you're using your devices in a vacuum with clear line of sight between aerials: +Unless you're using your devices in a vacuum with clear line of sight between aerials the following will have an affect: - Weather (temperature, humidity & air pressure), - Transmission power, spreading and other associated channel factors, - Number of nodes within reach in the mesh (affects retries consequent duty cycle hit), @@ -13,7 +13,7 @@ Unless you're using your devices in a vacuum with clear line of sight between ae - Reflection off surfaces (and channeled through material tunnels, including warm / cold air tunnels commonly present in the atmosphere), - Diffraction around obstacles (over forests and around corners). -### Environmental +### Environmental factors For a bit of light reading on environmental research: - [RF attentuation in vegetation](https://www.itu.int/dms_pubrec/itu-r/rec/p/R-REC-P.833-9-201609-I!!PDF-E.pdf) (yes really); if you wander through the woods wondering how your RF is bouncing off leaves dependent on their variety, and wind speed … well you do, now. diff --git a/website/docs/hardware/antenna/resources.md b/website/docs/hardware/antenna/resources.md index de021f25..ef0ffd3f 100644 --- a/website/docs/hardware/antenna/resources.md +++ b/website/docs/hardware/antenna/resources.md @@ -29,6 +29,8 @@ slug: /hardware/resources * [Solwise Link Budget Calculator](https://www.solwise.co.uk/link-budget.htm) * Predict the received signal strength +* [Amateur Radio Toolkit](https://play.google.com/store/apps/details?id=com.daveyhollenberg.amateurradiotoolkit) + * Android app with lots of antenna information ### Antenna designs diff --git a/website/docs/hardware/antenna/testing.md b/website/docs/hardware/antenna/testing.md index 6ac970dc..f4d8abb0 100644 --- a/website/docs/hardware/antenna/testing.md +++ b/website/docs/hardware/antenna/testing.md @@ -30,4 +30,6 @@ Here are a [couple](https://medium.com/home-wireless/testing-lora-antennas-at-91 ## Antenna matching & vector network analysers -One of the first things to ensure is that the antenna you have is tuned to the frequency that you are using. A lot of cheap antennas come labeled with an incorrect working frequency, and this will immediately reduce the emittted signal stregth. A Vector Network Analyser (VNA) can be used to ensure that the antenna is appropriately matched to the tranmission circuit, ensuring that it is operating at the correct impeadance and has a low level of power reflected back from the antenna to the transmitter at the desired transmission frequency. Andeas Speiss (the 'guy with the Swiss accent') gives a great explanation of [how to use Vector Network Analysers](https://www.youtube.com/watch?v=ZpKoLvqOWyc) to correctly tune your antennas, as well as a more [in depth tutorial of how to use VNAs](https://www.youtube.com/watch?v=_pjcEKQY_Tk). It is important to remember however, that VNAs can only tell you if the antenna is well matched, not how well it is transmitting. A 50 ohm resistor across the transmitter output would show as ideally matched, but it would be useless at transmitting a signal. There are a number of VNAs now available for less than $100, making this no longer out of reach for most hobbiests unlike expensive spectrum analysers. +One of the first things to ensure is that the antenna you have is tuned to the frequency that you are using. A lot of cheap antennas come labeled with an incorrect working frequency, and this will immediately reduce the emittted signal stregth. A Vector Network Analyser (VNA) can be used to ensure that the antenna is appropriately matched to the tranmission circuit, ensuring that it is operating at the correct impeadance and has a low level of power reflected back from the antenna to the transmitter at the desired transmission frequency. + +Andeas Speiss also gives a great explanation of [how to use Vector Network Analysers](https://www.youtube.com/watch?v=ZpKoLvqOWyc) to correctly tune your antennas, as well as a more [in depth tutorial of how to use VNAs](https://www.youtube.com/watch?v=_pjcEKQY_Tk). It is important to remember however, that VNAs can only tell you if the antenna is well matched, not how well it is transmitting. A 50 ohm resistor across the transmitter output would show as ideally matched, but it would be useless at transmitting a signal. There are a number of VNAs now available for less than $100, making this no longer out of reach for most hobbiests unlike expensive spectrum analysers.