90662A Grid-Dip Meter

This is a later version of the famous 90651 vacuum tube grid dip meter. It differs greatly from the 90651 with the addition of a front rotary switch to select diode detector, oscillator and modulator functions and a potentiometer for meter sensitivity adjustment. On the top side is a drum dial which is calibrated into seven scales for a frequency coverage from 220Kc to 300 Mc. This seven band coverage is achieved through plug-in coil assemblies which can be seen in the upper picture. The 90662 series (90661 also) were considered the Industrial Grade grid-dip meters. They were built to higher calibration standards, with each coil being adjusted to each dipper, thus providing increased frequency readout accuracy.

This wonderful unit belongs to Ed Zeranski. Ed purchased the dipper from Doug Dilley, WA6VOV who used it for work on many of his patented antenna designs.