The Unraveling of Drake's TR-4 Series SSB Filter Scheme

By: Jeff Covelli, WA8SAJ

Ever since the Drake TR3 and TR4 series transceivers built there has been many questions about why the SSB switch and the associated LSB/USB lamps toggle back and forth between the band selection, why there is no fixed or marked switch setting for selecting LSB and USB, and why 20 meters is reversed on the tuning dial from the other bands.

Here is an excellent article written by Jeff Covelli, WA8SAJ that explains the "why's" of the SSB switchng and shows you the math behind the transceiver design.

Click here to read Jeff's Article.    "The Unraveling of the Drake's TR4 Series SSB Filter Scheme"

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