Article below is a part of the assembly process of the UHF duplexer – main article is HERE.
Drawing below shows a [AL100] – Coupling Loop Bar TX (L).
Main purpose of the part is to make a copper loop which engages the signal inside of the cavity. Loop is made of 1mm thick and 4mm wide copper. Also I decided to extend the loop inside of the chamber and get both ends to work as capacitor – so no need to use any external capacitor 🙂
DO NOT BEND the last 40mm length – you will do it after assembling the [AL100] – 8mm Aluminium End Cap Top – otherwise you won’t be able to put it through the teflon grommets!!
Please note the RX coupling loops are slightly different!
![](https://www.rozenek.com/wp-content/uploads/2022/11/AL100-Coupling-Loop-Bar-TX-L.png)
![](https://www.rozenek.com/wp-content/uploads/2022/10/all-soldered-conductors-scaled.jpg)
![](https://www.rozenek.com/wp-content/uploads/2022/10/homebrew-duplexer-coupling-loop-bending-jig-scaled.jpg)
![](https://www.rozenek.com/wp-content/uploads/2022/10/homebrew-duplexer-coupling-loop-prepared-for-soldering-scaled.jpg)
![](https://www.rozenek.com/wp-content/uploads/2022/10/duplexer-catity-soldering-jig-heat-isolation-scaled.jpg)
![](https://www.rozenek.com/wp-content/uploads/2022/10/homebrew-duplexer-coupling-loop-soldered-to-a-copper-plate-scaled.jpg)
![](https://www.rozenek.com/wp-content/uploads/2022/10/homebrew-duplexer-coupling-loop-soldered-to-a-copper-plate-2-scaled.jpg)
![](https://www.rozenek.com/wp-content/uploads/2022/10/homebrew-duplexer-coupling-loops-and-main-conductor-soldered-to-a-copper-plate-scaled.jpg)
![](https://www.rozenek.com/wp-content/uploads/2022/11/Cavity-Duplexer-TX-Notch-Capacitor-made-from-copper-strips-scaled.jpg)