Hi Charles, what you refer is the resistance relation referred to the LM299 source around 14VDc but you have to consider the tuning range of the pot, in the original HP5065A is 2E10-9. Of course, it depends on the setting value of the variable resistance, but you have to consider a possible variation of 20PPM/c on 2E10-9. Regards Luciano timeok
Da "time-nuts" time-nuts-boun...@febo.com A time-nuts@febo.com Cc Data Tue, 21 Nov 2017 06:31:25 -0500 Oggetto Re: [time-nuts] HP5065A C-field mods and optical unit mods Luciano wrote: > about the C field ten turn pot you write is a low TC pot. Normally a good Vishay pot is 20 PPM/C, This is in conflict with the 1PPM resistors ad voltage reference. In the schematic Corby posted, the potentiometer (used as a variable resistor) makes up a very small part of the total resistance of the series string, so the overall tempco is dominated by the tempcos of the fixed resistors (2.4k to 4.4k 1ppm/ C, depending on trim). The pot will increase the overall tempco a little bit, but not anywhere near 20ppm. 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.
