Re: New FT8 Digital Mode Easier on IRF510?


AA7US
 

Hi Bob,

I'm surprised that the IRF540 is working as a good replacement for the original IRF510.

The IRF540 has a significantly higher input capacitance (1700 pF) compared to the IRF510 (180 pF).  From what I've read, higher MOSFET input capacitance requires higher drive levels.  Also, the IRF540 is slower to respond than a IRF510.

I wonder if the IRF540 has decreased the transmit power?

Maybe Adam can comment on this.

73,

John
AA7US

---In CHINA_QRP@..., <vk2aor@...> wrote :

Hi John and all

Also my local supplier did not have the original FET but a higher current rating and seems to work well. (IFR-540)  

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