The use of field effect transistors in this circuit improves its performance. This configuration is from a 1975 circuit manual. The transistor can be any general-purpose FET such as MPF102 or BF245.
This antenna for the frequencies 146 or 440 MHz was found in a magazine 73 for Amateur Radio of...
We found this circuit in an 80's EDN. The circuit makes use of a MAX680, being given a table with...
This circuit was found in a 1986 publication. However, it can still be easily assembled, as the...