Unlike with the
Kolster K-20 radio, whose Radio Service Data
Sheet I also just posted, I could not find a photo of this Columbia Screen Grid 8 (SG-8) radio. If you
have found this page because you have a Columbia SG-8 and are restoring it, please consider sending
me a photo for posting.
October 1930 Radio-Craft
Wax nostalgic about and learn from the history of early electronics.
See articles from Radio-Craft,
published 1929 - 1953. All copyrights are hereby acknowledged.
Columbia Screen-Grid 8 (SG-8) Receiver
This is a standard radio receiver merchandised under a number of individual trade marks. For instance,
Wextark Radio Stores, Inc., of Chicago, distribute this chassis; and so does Allied Radio Corporation,
Chicago,. Its manufacturers are the Columbia Radio Corp., Chicago, Ill. If oscillation exists, only
between 95 and 100 on the tuning scale, changing the RF. chokes above mentioned for units having 650
or 675 turns will probably eliminate this tendency, which may exist in a few instances. The reason for
this circuit oscillation is that the chokes are designed to resonate at a wavelength just above the
upper end of the broadcast band; this results in obtaining more even amplification throughout the tuning
Posted July 29, 2016