Buy Comet CF-416B Duplexer for transmitting and receiving the 144 (or HF/50Mhz) and 433Mhz at the same time.
Combined high grade filters work for preventing TVI at the same time. In the case of using the CF-416 for one frequency, the other end can remain open, although the use of a dummy load would be preferred.
* BandPass Frequency & Input Loss : * 1.3 - 170Mhz / Less than 0.15dB * 350 - 540Mhz / Less than 0.25dB * Impedance : 50 Ohms * VSWR : Less than 1:1.2 * Maximum Input Power : * 1.3 - 60Mhz / 1000Watts (PEP) * 100 - 170Mhz / 800Watts (PEP) * 350 - 540Mhz / 500Watts (PEP)
* Input 1 x SO239 Socket * Output 1 x Lead with fitted PL259 Plug * Output 1 x Lead with fitted N Type Plug