Preamplifier stage (CB8934E)

This circuit is from a 90s Popular Electronics. It appears elsewhere on this site. Q1 can be any general purpose transistor.

15 V x 1 A Power Supply Using the LM723 (CB862E)
The output voltage is adjusted by the trimpot. The power transistor mist be mounted on a heatsink. The 3.9...
Simple MW Radio (CB4359E)
Originally, this circuit is from an English magazine, but I found it in Argentina's Radio Chassis...
Retriggerable Monostable Using the 4047 (CB136)
The previously mentioned versions of monostable multivibrators in this section are not...