Thats fantastic to see. Yes you have it. Use an opamp to insert an offset of 6-7V so the DAC itself still uses its normal range of 0-5V. Opamp output would be 6-11V or something. You just may have the unit for a while longer. Regards Paul WB8TSL
On Tue, Jan 12, 2021 at 8:19 PM Scott Newell <[email protected]> wrote: > At 01:27 PM 1/12/2021, paul swed wrote: > > >Granted at 5V the varicaps may be at minimum. Use a 2K R. That should be > >pretty safe. > > Current limited bench supply though 4.7 k and an inline DMM to > monitor current. Made quick-n-dirty measurements of EFC voltage, EFC > current, and output frequency. > > It looks promising. Dead-bug op-amp, gain of 2, powered by > unregulated input supply (12-15 VDC)? That should get me enough EFC > range for a few years, assuming the loop can cope with double the EFC > sensitivity. > > 1 V 4 uA 9.999 991 MHz > 2 V 9 uA 9.999 992 MHz > 3 V 15 uA 9.999 994 MHa > 4 V 27 uA 9.999 995 MHz > 5 V 41 uA 9.999 996 MHz > 6 V 56 uA 9.999 997 MHz > 7 V 70 uA 9.999 998 MHz > 8 V 85 uA 9.999 999 MHz > 9 V 100 uA 10.000 001 MHz > 10 V 115 uA 10.000 001 MHz > 11 V 129 uA 10.000 002 MHz > 12 V 144 uA 10.000 003 MHz > 13 V 159 uA 10.000 004 MHz > 14 V 173 uA 10.000 005 MHz > 15 V 188 uA 10.000 006 MHz > 16 V 203 uA 10.000 006 MHz > 17 V 217 uA 10.000 007 MHz > 18 V 232 uA 10.000 007 MHz > 19 V 247 uA 10.000 008 MHz > 20 V 261 uA 10.000 008 MHz > > -- > newell N5TNL > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
