The first appearance was in 1929 as an emergency filler after the regular cartoon didn't show up.   Every day he did a one-panel commentary on some part of life - politics, automobiles, in-laws, restaurants, nothing was sacred.
 
Sunday's cartoon was in color and four times the space, but still one panel, and the additional room gave him space to include more characters.

Here is Hatlo's only known strip on the topic of ham radio. Jimmy Hatlo died in 1963.