?

Yes, you monitor current into the final when setting the IRF510's bias. ?Ashhar's "Wire Up" notes suggest setting the bias for 100ma. ?Just be aware that (as I read the datasheet) the current goes from almost zero to 10 Amps over about 1/5'th of the 5v range available to that pot, and 10a*12v = 120 Watts is enough to blow the top of that IRF510 across the room. ?A fuse of some sort might be a good idea, though will cost you about as much as the IRF510.

On the other hand, I'm not seeing many reports here of people blowing the final, so I'm probably getting a little carried away.

Regarding whether the IRF510's can run reliably at 24v for higher power:

> Good thing they never saw this:

> ? ?

Note that he's running all those IRF510's with 40v on the drain.

That design is very aggressive, and not just in the choice of drain voltage.

So my take is that his IRF510's blew at about 41v.

Jerry, KE7ER

---In BITX20@..., wrote :

you must look the current ,about 50ma (witahout input signal) ..voltage is not imporant but in my case is 3,4v on gate irf 510