The filter presented is from 1994 but can be implemented with a more modern equivalent. We found this setting in the National Semiconductor Linear Applications Handbook.
This circuit appears elsewhere on this site. Although the 8038 is not an easily obtainable...
The Texas Instruments TPS80 LDO (Low Dropout) series (www.ti.com) can provide fixed or adjustable output...
Found in Radio Electronics, this simple indicator circuit uses general-purpose transistors common today....