NEW AND SOMEWHAT IMPROVED...   ACTIVE ATTENUATOR PROJECT

Above, the schematic is shown for the "new and improved" RDF active attenuator.
Note that the 100, 100, 82 Ohm resistors act as a 10 dB attenuator in series with the antenna.  If the attenuator is not needed... then leave the resistors out and connect the 100 pf capacitor directly to the antenna input BNC jack.

The four 1N4181 / 1N914 diodes shown connect to the antenna input jack.  These diodes act as a RF voltage limiter. If more than 1.4 volts of RF is present at the antenna then the excess is shunted to ground.

The 5 V voltage regulator is now a LM7805, TO92 case, which reduces its size by about 75 percent.

The little green capacitors on the regulator board are 100 pf caps that shunt any VHF frequencies from the bunny that have worked their way into the compartment... to GND.