-------- Bob kb8tq writes: >If a more extensive rebuild is in the works …..
Yes, that's where we're headed eventually, but I prefer to do it incrementally. >+/-20V is (as has been observed) not an ideal voltage for “modern” >electronics. Right, and being able to drop that down later is in the design. However, from a noise point of view, there is a lot to be said for having local LDO's on individual subassemblies. >A11 Unless you want to redo the heater windings on A12, you are >stuck with +20 to +30V. Rest of the board sort of begs for a modern >op-amp approach. I have not given much thought to A11 yet, and I do find a certain elegance in the wien-bridge approach. It is worth noting that the actual heaters run of the unregulated supply, when I stabilized that, A11 worked less hard. Unless you plan to run the HP5065 at the freezing point, I expect the heaters could run of a lower voltage, though +15V may be too low. >A14 If the upstream boards get changed, this likely does as well. >Sort of begs for a $1 MCU and a handful of resistors as a replacement. I was actually pondering doing that on A17. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
