02-16-2019, 11:44 AM
Found this small advertisement for the Trol in 1956 radio electronics. Go to page 130 lower right hand side. Couldn't find any info on the Columbia Products INC. company.
https://www.americanradiohistory.com/Arc...956-11.pdf
https://www.americanradiohistory.com/Arc...956-11.pdf