The MX-72N duplexer is designed to connect two transceivers on one antenna.
Port-1 (1.6 MHz to 150 MHz) for an HF or VHF radio.
Port-2 (400 MHz to 460 MHz) for a 70 cm band radio.
I made the following measurements using the DL2SBA vna/J software:
- Isolation between HF/VHF and 70 cm band ports
- HF/VHF insertion loss
Isolation between the ports
Diamond claim 60dB isolation between the ports. Let's check if is correct. The duplexer HF/VHF and the UHF ports are connected to the 'DUT' and 'DET' of the miniVNApro. A 50 Ohms load is connected to the 'MIX' connector.
The vna/J software is used on 'transmission mode'
HF/VHF transmission loss (TL)
The duplexer HF/VHF port is connected to the 'DUT' and the 'MIX' port to the 'DET' of the miniVNApro. A 50 Ohms load is connected to the 'UHF' connector.
The vna/J software is running in 'transmission' mode.
The graph shows an insertion loss of about 0.10 dB for the HF band and 0.28 dB for the 2 meters band.