What the receivers lacked in selectivity, they more than made up for in sensitivity, didn\'t they? they were TRF w/ regen detectors, like a US Navy RAL, weren\'t they?
Roy, I know Spark had pretty much rasped it\'s last among US Hams by the mid-20\'s, but didn\'t it survive on the high-seas above 600M till almost the outbreak of the War?

73,
John WB9OFG