I installed a Zenar diode to protect my (tr)uSDX against high SWR and replicated the same experiment conducted by Barb WB2CBA (the video I forwarded to this forum a while ago).

With a dummy load the (tr)uSDX shows 2.97 watt output and SWR 1.1. Without the dummy load SWR shot up to 101.5 but no smoke or visible damage.?

The third photo shows how the diode was installed in my XH2 (you remember the Poor Man’s KH1?) which is made from a Hi-band (tr)uSDX kit.

So I am totally convinced that a single Zenar diode does protect your (tr)uSDX and other USDX radios.

Hiroki AH6CY