Improved readme documentation.

Author: kaklik

README.md

@@ -1,36 +1,56 @@
-# QFHBAL01 - Antenna interface and balun
+# QFHBAL01 - Antenna Interface and Balun
 
-[Balun](https://en.wikipedia.org/wiki/Balun) for QFH antennas
+The **QFHBAL01** module is an [antenna interface and balun](https://en.wikipedia.org/wiki/Balun) designed for QFH (Quadrifilar Helix) antennas, supporting right-hand (RHCP) and left-hand circular polarizations (LHCP). This module enables efficient impedance matching and balanced transmission in QFH antenna configurations.
 
 ![QFH antenna balun](/doc/src/img/QFHBAL01.png)
 
-## Mechanical drawing
+## Key Features
 
-![QFHBAL01 Dimensions](/doc/src/img/dimensions.png)
+- **Polarization**: RHCP and LHCP
+- **Frequency Range**: 4.5 - 3000 MHz
+- **Insertion Loss**: 2 dB typical
+- **Amplitude Balance**: ±1 dB
+- **Phase Balance**: ±20°
+- **Power Rating**: 250 mW max RF, 30 mA max DC
+- **Operating Temperature**: -55 °C to +85 °C
+- **Dimensions**: Diameter 32 mm, Height 20 mm
+- **Weight**: 10 g
 
+## Transformer Mounting Options
 
-## Electrical interface
+The **ETC1-1-13** transformer on the QFHBAL01 module can be soldered onto the PCB in two configurations:
+
+1. **Galvanic Isolation**: Isolates the antenna from the RF line, enhancing protection for the receiver input but potentially increasing insertion loss slightly.
+2. **Direct Galvanic Connection**: Connects the antenna directly to the RF line without isolation, minimizing insertion loss but offering less protection for the receiver input.
+
+These configurations allow customization based on application requirements for input protection and insertion loss.
+
+### Balun Polarization and Connection
 
 ![Balun connection](https://uuki.kapsi.fi/pix/qha/qha-diagram_medium.png)
 
-| Helices | Feedpoint | Radiation | 	Polarization |
-| ------------- |:-------------:| ----- | ----- |
-| Left-hand |	Standard |	Upward |	RHCP
-| Right-hand |	Anti-standard |	Upward |	LHCP
-| Left-hand |	Anti-standard |	Downward |	RHCP
-| Right-hand |	Standard |	Downward |	LHCP
+| Helices     | Feedpoint      | Radiation | Polarization |
+|-------------|----------------|-----------|--------------|
+| Left-hand   | Standard       | Upward    | RHCP         |
+| Right-hand  | Anti-standard  | Upward    | LHCP         |
+| Left-hand   | Anti-standard  | Downward  | RHCP         |
+| Right-hand  | Standard       | Downward  | LHCP         |
+
+*Source: [QHA Simulation](https://uuki.kapsi.fi/qha_simul.html)*
+
+## Schematic and Mechanical Drawing
+
+- [Schematic (PDF)](/doc/gen/QFHBAL01-schematic.pdf)
+- [Mechanical Drawing (PDF)](/doc/src/img/dimensions.png)
 
-[source](https://uuki.kapsi.fi/qha_simul.html)
+### ETC1-1-13 Transformer Specifications
 
+The **ETC1-1-13** transformer offers a 1:1 impedance ratio suitable for balanced RF transmission:
 
-### Main Parameters
+- **Frequency Range**: 4.5 - 3000 MHz
+- **Insertion Loss**: 0.32 dB typical, max 3.5 dB at high frequencies
+- **Amplitude Balance**: ±1 dB
+- **Phase Balance**: ±20°
+- **Power Rating**: 250 mW max
+- **Operating Temperature**: -55°C to +85°C
 
-  * Polarization configurations:  RHCP, LHCP
-  * Insertion Loss 2 dB
-  * Amplitude balance +/- 1 dB
-  * Phase Balance +/- 20 degree (°)
-  * Maximum RF power 250 mW (+23 dBm)
-  * Maximum DC current 30 mA
-  * Operating Temperature -55 °C to +85 °C
-  * Dimensions: 32mm diameter 20mm height (including RF connector)
-  * Weight 10 g

hw/sch_pcb/QFHBAL01.kicad_prl

@@ -1,7 +1,7 @@
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