i know as i have not been able to find out how many amps the receiver and transmitter drew is what happened on the flight to hawaii we know about when the generator went off line and we know when they landed the rest is deduction what i cannot tell you is if they were down on an island on their belly see lambrechts opinion of landing chances on gardener how long they could operate their radios or if their electrical system would have been intact enough to function i grew up in the age of the vacuum tube and know that it would take a minute or two to 'warm' up the dynamotor and transmitter to the point where it would achieve full power this is all assuming they had no serious damage to the airplane my 'best guess opinion don't ask me to put it in the article is that they probably had at least one hour of operation the other question is how much gain they would have gotten from a less than optimum to quote the tighar radio guy length under wave v type antenna sitting less than six feet off the ground the answer is probably but not definitely not much we are looking at an actual output from the antenna of perhaps watts with a horizontal polarity and bad angle perhaps they were heard odds are they were not i repeat this is opinion still we need to consider these things my guess is that earhart opinion could have transmitted and received for at least hour that she could have done one or the other longer one must remember that a dynamotor was a pretty inefficient means of turning low dc voltage into high voltage ac for radio communications thus the receiver alone would have more operational life than the transmitter once again we do not know how many minutes the xmitter or receiver were on during the hawaii flight but a good guess is that they both ran all the time that the propagation characteristics of her antenna and the frequencies she was able to operate on severely limited any possible range i find it far easier to think that reports of a 'weak carrier or 'feeble and unintelligible communications being hear are far more likely than someone who claimed to hear her the bottom line in my humble and we all know how humble i am opinion is that given the best of circumstances they would have had at least one hour of radio time left if they were out of fuel