Final PA SWR protection with zener diode?
Posted: 16 Mar 2023, 16:25
Greetings! I'm on vacation in 9H/Malta and I brought the (tr)uSDX with me. I was able to make a number of contacts on FT8 and CW with an EFHW off the hotel balcony, but somehow I managed to blow out the final transistor. I'm using the "high band" board, which I assembled, and I bought from a DL2Man approved vendor.
I'm not sure how I blew it--I'm using the "QRPGuys" EFHW tuner. The "Watts" setting when I key down in CW, whether or not 12v is connected says "0.01 watts".
When I get back home and can fix it, I was wondering if there's anything I can do to protect the final. I see that some users of similar style QRP rigs use a zener between Drain and Ground. (See https://www.youtube.com/watch?v=7hUmkE84kfA )
Have any of you tried that with the (tr)uSDX, would it be connected the same way, what voltage Zener do I use, etc?
Thanks!
I'm not sure how I blew it--I'm using the "QRPGuys" EFHW tuner. The "Watts" setting when I key down in CW, whether or not 12v is connected says "0.01 watts".
When I get back home and can fix it, I was wondering if there's anything I can do to protect the final. I see that some users of similar style QRP rigs use a zener between Drain and Ground. (See https://www.youtube.com/watch?v=7hUmkE84kfA )
Have any of you tried that with the (tr)uSDX, would it be connected the same way, what voltage Zener do I use, etc?
Thanks!