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Re: Using IRF530 outputs and 2N3553 drivers in ubitx

 

Wow 940pf. ?You can design for it to work at 30 MHz but thats not gonna work at 3.5 or 7.0 MHz without switching parts in and out. ?

?

Dr.?William J. Schmidt - K9HZ

On May 16, 2018, at 7:48 PM, ajparent1/KB1GMX <kb1gmx@...> wrote:

That is consistent with my testing.

The 2n3904s are marginal for power and FT. So it shows a higher FT device that can run at
more power helps, 2N3553 will do both.? Other choices would be 2n3866 and 2n5109
and along list of others.

The IRF530 is an odd choice as below 10 mhz its been used by many but over 10 its input
capacitance (940PF vs 135 for the IRF510) makes it a more difficult part to feed.

Did you change the predriver as well?

How is the power out at 28mhz?

Allison
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