Hi Steve,
I asked myself a similar question and decided to measure things both terminated and un-terminated. Bottom line is you want to terminate that unused port.
Here is a story on my website: https://wb4son.com/wpblog/?p=2828
73, Bob, WB4SON
On Sun, Nov 10, 2019 at 6:18 PM AI9IN via AMSAT-BB amsat-bb@amsat.org wrote:
My satellite rig is two HTs running to an Arrow antenna. Trying my best to operate full duplex. When operating V/U I am using the UHF side of the Arrow duplexer as a high pass filter between the UHF antenna feed point and the UHF HT to keep the 2 m transmit signal from desensing the UHF receive.
But it only sort of works.
This set up leaves the VHF end of the duplexer open and just hanging. Would this setup work better with a 50 ohm load across that empty connection? (Sorry if this is a dumb or elementary question, but I'll never find out if I don't ask.)
All helpful insights are welcome.
Steve AI9IN _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb