in reply to
printing to filehandle contained in a hash
Hash keys are stringified. When you used the file handle reference as hash key, perl turned it into a string representation of the reference. The reference itself is gone!
Perhaps a hash wasn't the right choice for your data structure. Since all you're doing is iterating over your data anyway, perhaps an array of arrays (AoA) would be more useful. Untested:
# Somewhere earlier...
my @radar = ();
push @radar, [$fileh, $repoch] for (1..5);
# ... then:
my ($fileh, $repoch) = @$_;
# ... continue as before.