Total posts : 45366
A REMCO Transistor Radio, circa late 50’s http://www.ohio.edu/people/postr/bapix../Remco.htm. It was really just a crystal radio despite the name. It had exactly 3 more components than the REMCO Crystal Radio: a resistor, an early point-contact transistor as an audio amplifier and a 1.5 V battery. The crystal was a 1N34A.
I just dangled the antenna out the second story window and connected the ground wire under the screw in the center of the valve on the hot water radiator.
Being in a very rural area, I got mostly nothing during the day, but at night it came alive with a jumble of signals. I don’t remember actually hearing an AM broadcast band station. The jumble was obviously short wave signals like morse code and foreign languages.
I somehow thought I might get better performance by increasing the battery voltage with another 1.5 V in series, so I tried it. That made a dramatic improvement. Daytime reception increased to the former nighttime level and nighttime was a cacophony of loud signals. That lasted for a day or two before the transistor blew out. Then I junked it in frustration. Hey, I was just a kid!
Check the web for crystal radios. The hottest ones no longer use the increasingly harder to get 1N34A crystal. They are now using a “zero threshold” mosfet IC connected without external power. The 1N34A has a threshold voltage of .3V. The mosfet has a zero threshold, so it responds to lower RF voltage allowing tapping down on the coil, which results in higher tuning Q. http://www.arrl.org/files/file/Technology/tis/info/pdf/culter.pdf