[time-nuts] HP5065A C-field mods and optical unit mods
csteinmetz at yandex.com
Tue Nov 21 15:16:36 EST 2017
> 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.
No, you don't. The tempco that matters is the aggregate tempco of the
series string. Only a very small portion of the string voltage appears
across the pot, so a 20ppm tempco of that small part will cause a much
smaller change in overall tempco of the series string.
Perhaps Corby will tell us what value the pot is, and then you can
calculate the aggregate tempco of the string at various pot settings and
see for yourself.
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