(1) Journal of Post Keynesian Economics;Of course, a number of these journals also publish work in other heterodox traditions, such as non-neoclassical institutionalism and Marxian economics, in addition to Post Keynesian economics.
(2) Review of Keynesian Economics (with the Elgar online page here);
(3) Cambridge Journal of Economics;
(4) Real World Economics Review;
(5) Review of Radical Political Economics;
(6) Journal of Economic Issues.
Most probably, I have missed important ones, and am happy to receive suggestions and additions.
For example, are the Review of Social Economy and Science and Society venues for Post Keynesian economics too? (they are listed as heterodox journals in Lee 2009: 47).
Also of interest are the following resources:
Lee, Frederic S. 2009. A History of Heterodox Economics: Challenging the Mainstream in the Twentieth Century. Routledge, London and New York.