We found this circuit in a 1967 American documentation. It is a transmitter for animal research, monitoring intestinal pressure. The operating frequency is 22 kHz.
This circuit is from an English publication from 1965. The transistors used are rare, however, they...
This low voltage circuit was found in the November 1960 Radio Electronics magazine announcing new...
We found this circuit in a 2003 publication. The indicated coil is for capturing the signals in an...