Hi Merle,
Short answer is No.? The C150,R150 junction is the T/R signal from the Raduino/Nano.
so the other side of C150 is at GND.? You have it drawn as +5 VDC.
From a quick search, I didn't find the original circuit from VA3EPM to compare.
If wanting to use a relay, copy the uBITX relay driver and not drive a relay directly from Nano.
Last year, I built a project using a 12V relay board from Amazon
ASIN ? : ??B097F3W37C
This breakout board is easy to use. contains driver, and jumper to select energize on H or L.?
I recommend handling the amp switching through an opto-coupler.
A photo MOSFET, makes it easy to low side switch.
https://www.mouser.com/datasheet/2/408/TLP3558A_datasheet_en_20200325-1916539.pdf
There are numerous opto-coupler breakout boards out there too.
Rgds,
Gary
