1955 EV 664 Variable D Microphone “phone” Ad

It you operate ‘phone YOU WON’T BE SATISFIED UNTIL YOU OWN
the completely new
664 VARIABLE D* CARDIOID DYNAMIC MICROPHONE


Click on the image above to see the full size version

The 664 will equal a useful power increase of four times over commonly-used peaked microphones, and could well be the best investment, dollar-wise, in your shack
Here is a totally new concept in microphones for amateur phone communication.