[ARC5] SCR-274N with B-24 Antenna

[Hubert Miller]

I also eagerly await some answer to this question. 
I recall one year of the ARRL Manual had a 'Command Set' transmitter conversion which said you could use down to a 15 foot antenna, at least on 40M.
Your antenna length does not sound excessive.
Some of us own the B-24 radio electronics book ( manual ). Kind of an odd item; no other aircraft manufacturer had such a specialized manual, that i have seen.
Also odd is the introductory educational material up front in the manual.
Anyway i'll have a look into it later to see what the book shows as the Command antenna.
-Hue Miller