The Keying Transistor used in the Harbach Soft Key uses an IRF610 HEXFET Power MOSFET, rated for 200V with an ON Resistance of 1.5 Ohm in a TO-220 Package.
The Elecraft K3 uses an IRF1630 HEXFET Power MOSFET, rated for 200V with an ON Resistance of .4 Ohm in a TO-220 Package. Don't see much of a gain by using the external device ..... 73 ---> Dave, W9ZRX > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:elecraft- > [EMAIL PROTECTED] On Behalf Of Don Rasmussen > Sent: Monday, 01 September, 2008 18:20 > To: [email protected] > Subject: [Elecraft] K3 Key Out > > I soldered up the soft key mod today, it's inexpensive > and simple to install. > > http://www.harbachelectronics.com/_mgxftp/pdffiles/SK220PICTORIAL.PDF > > [Elecraft] K3 Key Out > David Robertson darjar at comcast.net > Mon Sep 1 17:40:33 EDT 2008 > > The K3 Key out may be rated for 200 volts but if you > use it with an unmodified SB220 you are taking a real > chance of damaging the K3 because there is no > protection diode in the SB220 and the field collapse > voltage can exceed 1000 volts. > > > the SB220 was originally designed for relay keying. > > 73 > Dave KD1NA > > > _______________________________________________ > Elecraft mailing list > Post to: [email protected] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
