Silver-Marshall 620
"Single Control Silver-Cockaday
Allwave Receiver"
Silver-Marshall Incorporated,
103 S. Wabash Avenue,
Chicago, Illinois, USA

    The Silver Marshall 620 was an allwave regenerative receiver kit which incorporated interchangeable coils in order to achieve a wide variety of frequency ranges.  All of the wiring is held together by a single harness and all electrical connections are achieved by mounting screws on all of the electronic components.  Because of this, and no solder was ever required, assembly was made quick and easy for the origional home builder.  This also makes the 620 one of the most easily restorable radios today, even for the most novice of collectors.  There is a note of caution when cleaning the front panel.  The artwork comprises of silver stenciling with a very thin coating of dark amber colored lacquer, giving the stenciling it's gold look.  Cleaning the panel by means of harsh chemicals and/or hard scrubbing will easily wipe away this amber coating leaving the stenciling with a silver look.

Tube Line Up:
01A.....R.F. Amplifier
01A.....1st. Det.
01A.....1st. Audio
01A or 12A.....Audio Output

Hight...9 inches
Wedth...28.5 inches
Depth...12.5 inches

Power Source:
Battery.....+6 Volts
Battery.....+45 Volts
Battery.....+90 Volts
Battery.....-4.5 Volts

Frequency Range:
Multable Frequencys

Schematic and information

Click Here to view the factory building on Terraserver.  The factory is the building just above the red dot.

Click to this website to a see a mid 1920s Silver-Marshall radio catalog which shows a photograph of the factory building.

Two page flier touting the SM 620 and SM long wave (intermediate) transformers for use in superheterodyne receivers.

This web page was last updated: August 29, 2020