Thanks Charles: I will consider your ideas as they seem to be excellent! I wonder if I could just make the whole unit run off of +24VDC or +12 VDC. I need to look at the schematics and see what would be the best way to proceed.
I currently do not have an antenna for WWVB and need to get up and running before I do anything with it. If successful, would anyone want information on my conversion? I also have a fluke 207 that needs to be recapped. Thanks, Ron -----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Charles P. Steinmetz Sent: Wednesday, July 04, 2012 11:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 117/10509a Don wrote: >the fet breakdown voltage has of course got to be high enough. If the nuvistor is used as a common-cathode or common-grid amplifier, you can cascode the fet with a bipolar to extend its drain voltage range. You will need to come up with an appropriate bias source for the bipolar. Generally, you would want at least 10-15 volts across the FET channel. Choose an appropriate JFET (transconductance, drain current, and gate-drain voltage similar to the nuvistor at the nuvistor's operating point). You can add degeneration (source resistance) to lower the FET's transconductance if it is higher than the nuvistor's. Best regards, Charles _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
