[time-nuts] "The Penultimate HP5065 A15" <C field switching>

[Tom Van Baak]

On 8/4/2020 10:21 AM, cdelect at juno.com wrote:
 >
 > Back in Nov 2017 I detailed my A15 mods:
 >
 > Set Zener current to minimum TC (I achieved < 1PPM/C at the +20V output)
 > This involved disconnecting the C-field circuit and replacing it with a
 > dual (in series ) LM299AH and 1PPM resistors.  Jumperable settings and a
 > low TC pot for adjustment. I would have liked to use 3 LM299AH to give me
 > 21 Volts but would need to switch the input to the unregulated supply to
 > give enough overhead. The higher the voltage into the C-field string the
 > lower the TC contribution from the C-field coil itself.
 >
 > The posts have the details and schematic.
 >
 > Cheers,
 > Corby

To save the rest of you time, here are some of Corby's 5065A posts:

"HP5065A C-field mods and optical unit mods"
http://lists.febo.com/pipermail/time-nuts_lists.febo.com/2017-November/090056.html
http://lists.febo.com/pipermail/time-nuts_lists.febo.com/2017-November/090067.html
http://lists.febo.com/pipermail/time-nuts_lists.febo.com/2017-November/090107.html
http://lists.febo.com/pipermail/time-nuts_lists.febo.com/2017-November/090138.html
http://lists.febo.com/pipermail/time-nuts_lists.febo.com/2017-November/090189.html
http://lists.febo.com/pipermail/time-nuts_lists.febo.com/2017-November/090255.html

/tvb