Matching antenna (CB7458E)

The coil and sockets of this circuit found in a QST depend on the frequency band that is intended to be tuned.

Mini LED Sequential (CB16235E)
For fans of sequential systems, here is another one found in a 1983 publication. Two CMOS...
Impedance Matcher (CB17194E)
This circuit, already explored in other applications on this site, allows using a high impedance...
RF detector (CB11517E)
In fact, it is a RF field indicator with an operational amplifier equivalent to the 741. This...