Review on Enhanced FM Reception: Male 'F' Connector FM Dipole Antenna by Darryl Blumenthal

Three stars is a conditional rating - if I get an answer to a question, I'll change it to 5 stars. Reception problem when this external FM antenna is connected to the radio. I bought an external VHF antenna "FM Dipole Antenna - Plug 'F'" from MCM Electronics that Revain recommends with the Sangean WR-15WL radio. With the switch on the back of the radio set to Int (internal antenna) reception is pretty good - at least 20 stations have a signal strong enough to light the green tuning LED. When the switch is in the Ext position and an external antenna is connected, reception will be poor and few signals will be strong enough to illuminate the green tuning LED. The documentation that came with the radio recommends an external 75 ohm antenna. Revain FM Dipole Antenna Information - MCM's "F" connector indicates it is a 75 ohm antenna. The reviewer who answers this antenna in the Q&A section disputes this, arguing that it is in fact a 300 ohm antenna. I've read a few websites that offer explanations of the various impedances in VHF antennas, but really didn't get it. So I don't know if I bought a 75 ohm or 300 ohm antenna and I don't understand why connecting this FM antenna to the radio degrades reception compared to using the radio's internal antenna.