Yes, there's no doubting that these modern FETs are generally quite
robust. For most amplifiers there's a range of phases of high VSWR where
they will survive ok, and a smaller range where they are most vulnerable
- usually where the drain impedance goes very high (breakdown volts) or
very low (dissipation from very high current). The second is probably
responsible for more failures, but it depends a lot on the diffusions in
the die.
Steve
Steve
I, inadvertently, tested mine when the output coax relay gave up it's
ghost, see the pictures toward the bottom of the page:
http://www.frenning.dk/OZ1PIF_HOMEPAGE/LDMOS_SSPA.html
The LDMOS survived! I was running Digimode at about the 750W level
when it failed.
-- Vy 73 de OZ1PIF/5Q2M, Peter
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