From 6cccff5dfad56b86703aa6589c3405aaeefe1e66 Mon Sep 17 00:00:00 2001 From: Konrad Roeder Date: Sat, 3 Sep 2022 18:00:02 +0000 Subject: [PATCH] Updated Antennas (markdown) --- Antennas.md | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/Antennas.md b/Antennas.md index fe40351..e09efa7 100644 --- a/Antennas.md +++ b/Antennas.md @@ -7,18 +7,25 @@ Photo courtesy Klaus Kitzmantel, OE5KKP DL9KX ## Polarization LoRa APRS uses vertical polarization exclusively. Vertical antennas are the best way to get an omni-directional pattern. They're vertically polarized. Yagi antennas are very directional, meaning they can produce gain in a certain direction. They're generally horizontally polarized. There are large signal losses when the polarization of the transmit antenna and the receive antenna don't match. It does not make sense for mobile units to transmit horizontal polarization. Therefore iGates and Trackers have pretty much standardized on using vertical polarization -##Antenna gain +## Antenna gain dBi - Gain over isotropic, a point source -##SWR +## SWR Standing wave ratio # Antenna mounts ## Magnetic +![image](https://user-images.githubusercontent.com/3480859/188282326-2c194436-3a0c-4c41-87c6-98ec59d1d144.png) + +![image](https://user-images.githubusercontent.com/3480859/188282391-62f4bb0f-df4a-4e58-a46d-758b992156c7.png) ## Trunk lip +![image](https://user-images.githubusercontent.com/3480859/188282459-aa4df731-5ea5-42ea-8ea0-af2b8ff60224.png) + +![image](https://user-images.githubusercontent.com/3480859/188282504-31a925dd-6308-4269-9b3c-75147a08a32b.png) ## Fender bracket or through roof +![image](https://user-images.githubusercontent.com/3480859/188282571-8df790eb-81cf-4c56-9b48-7cc857874a3b.png) # Antennas More height means more gain @@ -28,6 +35,8 @@ More height means more gain ## Low-cost 1/4 wave ## Rubber ducky +![image](https://user-images.githubusercontent.com/3480859/188282669-dbee7e16-7b79-4bdc-be57-e47d1ecfbb12.png) +