Search found 3 matches

by Bill Lahan
Mon Aug 18, 2003 9:27 am
Forum: General Discussion
Topic: Best AM Broadcast band Radio for dx?
Replies: 10
Views: 7225

Re: Best AM Broadcast band Radio for dx?

I have a CC radio and I am disappointed with the performance.<p>A good loop antenna works very well for this type activity.<p>The magnet loop is best because it offers better noise immunity.<p>Adding a low noise amp up front can help. It can be even bette is it is a tuned RF amp.
by Bill Lahan
Fri Aug 15, 2003 6:40 pm
Forum: General Discussion
Topic: Can MOSFET be used in PWM circuit
Replies: 15
Views: 3480

Re: Can MOSFET be used in PWM circuit

FETs work very well in this type application. There are two points to consider.<p>Use a FET with a low channel resistance.<p>Switching the FET OFF may require a bipolar drive to overcome the gate to drain miller capacitance.
by Bill Lahan
Fri Aug 15, 2003 6:17 pm
Forum: General Discussion
Topic: MOSFETS II
Replies: 9
Views: 1940

Re: MOSFETS II

This problem is not unknown!!<p>I am assuming an inhancment mode type FET.<p>One cause is the large miller effect capacitance between the gate and drain. Simply switching off the gate drive may not be adiquate to bring the FET into the off mode.<p>I have found that a bipolar drive +/- 12V maybe nece...