Zenith transoceanic and other portables with 1l6 emissions mystery

[Electronic M]

I dislike the idea of troubleshooting/repairing/restoring a set with a 1L6 installed during the process....It is a MUCH better idea to put a 1R5 in the set until you have all critical parts replaced and it is working correctly on AM. It is much better to blow a 1R5 than a 1L6 while fixing it.
Other than as a restoration safety (or a poor mans substitute until a 1L6 can be gotten) I see no use for the 1R5 in shortwave sets.