This circuit is from an 80's publication. It makes use of small 6 V x 50 mA incandescent lamps. The diodes can be general purpose or even 1N4002. The transformer is 6.3 V with 100 mA or more current.
The circuit presented was found in the 1994 Linear Applications Handbook from National...
This circuit, which in our times would be called a shield, can also be used with other loads. The...
This circuit is intended for amplification of signals in the range of 1.8 to 20 MHz. The...