Hiroki-
The zener? protection diode is a common design practice and is
favored by Wes Hayward, W7ZOI. In his ARRL publication
"Experimental Methods..." he explains the design on 1.19, fig.
#1.35. subsequent design examples feature this design component.
Your experiments confirm the usefulness and utility of his
recommendation. Great job.
Phil
On 6/14/2024 8:42 AM, Hiroki Kato
wrote:
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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
