How about a complete AM radio station that you can jump out of an airplane with?
I picked up an MAB more than 15 years ago. The MAB is a one channel walkie talkie that was used by Marine Paratroopers in the Island Campaigns of the South Pacific. The idea was that it could be used to call in artillery from ships or support runs from aircraft, once the troops were dropped in. What is interesting about this radio is that it is basically weather tight, with a fibercloth case and gasketed cables and even a waterproof on off switch. It takes a 6 V bias battery, a 1.5V fil battery and a tapped 135V supply to run it. Half of the package is XCVR and half is for the batterries. I managed to crystal it for 3885 (it covers 2.3 - 4.5 MC). I easily made up a battery pack consisting of 3 C cells in parallel (A Supply) 15 9V batteries (B Supply) and 4 AA cells (C Supply) and it worked like a champ. I used it a a couple of Hosstraders.
Then something bad happened - it went dead
. This radio was made to be used once and discarded once the battery pack went dead in 1945 and it is miniature contruction in every sense of the word. I did not look forward to attempting a repair! In fact I have procrastinated for 10 years! The entire tranciever box is 6 X 3 X 1 Inch and it weighs less than 14 oz! The whole transciever is made of 7 brand new miniature battery tubes which were very new at the time it was designed in 1941.
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Mike WU2D