So, there is no "data" to be gleaned from forum posts regarding failures due to high SWR of IRF510's?
I'm done here.
Jerry
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On Sun, Apr 29, 2018 at 11:16 am, K9HZ wrote:
Jerry you know the uBITx PA design is nothing like the WA2EBY design, so why would you expect the same result?? It escapes me why people bring this up.? The commonality is that they use the same PA transistors and that¡¯s pretty much where it ends.? We¡¯ve both done simulations on both systems and understand the differences precisely (given the ¡°S¡± params we have).
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A closer study of the datasheets for the IRF & RD devices tell the story.? Failures in the IRF device is likely caused by the degree of coupling between the gate and drain.? Allison in another post wrote: ¡°This is more often seen with higher capacitance devices like IRF510.? The failure mechanism is with high RF voltages ?on the drain it¡¯s is coupled back to the gate by the gate to drain capacitance and if the source (driver) ?impedance is not low enough the gate can reach a voltage that exceeds its breakdown level ?(20V or less) this leads to gate oxide punch through and the device fails.¡±
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Now no one should be alarmed by this post.? If you treat your radio right, there will be no PA problems.
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