A basic one transistor regen receiver uses an MPF102 JFET to give the regenerative gain. Also uses two transistors to amplify the audio to drive an earphone. How to Build an FM Radio Receiver
Archive for the ‘Field Effect Transistors FETS’ Category:
2024-02-27 MOSFET Driver
The gate driver circuit shown in the screenshot uses BC547s, which are limited to less than 200 mA current. Instead, if the two transistors were BC337 or PN2222A which can easily handle over 500 mA, they could charge and discharge the gate faster, and thus reduce the dissipation in the MOSFET.
2024-02-17 BJT, FET Curve Tracer
This very comprehensive website has a transistor and FET Curve tracer. Also a simpler curve tracer for all components. Click on box to download the schematic, etc. https://www.changpuak.ch/electronics/Curve_Tracer_advanced.php#
2020-06-01 Motorola HEP Catalog Transistors pp 10-12
These are scans of the specifications for most of the Motorola HEP line of replacement transistors. Germanium and Silicon. Pages 10, 11, 12.
2016-10-18 FM Transmitter Uses Power MOSFET
I watched this YouTube video where the author shows his FM transmitter using a big 60 volt power MOSFET. He also shows a very readable photo of the schematic. The video was made several years ago in 2012. He is powering this transmitter by connecting it to eleven 9 volt batteries in series, totalling 99
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2016-10-03 Ordered Thru Hole Transistors
I went online a few days ago and looked for some odd RF transistors, but instead I was shocked. Almost all of the parts I’ve been using are through hole parts, like transistors in a TO-92 package with wire leads. I looked at a few distributors such as Mouser, Avnet, Arrow, Digikey, Newark. I found
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2016-06-04 Crystal Radio Coils, Crystal Diodes
I was reading some of Geo John’s projects and came across a crystal radio set that he built using two tuned coils. A crystal radio set refers to the type of detector used, which was once a galena crystal and a ‘catwhisker’ to find a sensitive spot on the crystal. Nowadays, that is no longer
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2015-12-16 JFET Joule Thief
I captured this off a video and tried to make it a bit more readable. I think it was from Sanjev. I built it and it does work at 40 millivolts. The 2SK170 JFETs are not common, and may be difficult to obtain. Other JFETs can be used, but I haven’t tried them. I wrote
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2013-08-04 A Low Voltage JT Using 2SK170 JFET
Fellow JT experimenter Quantsuff has been experimenting with a Joule Thief using the 2SK170 JFET, and it runs at 131 millivolts (0.131V), powered by a solar PV cell lit by a table lamp. This is a very good JFET for low voltages; I made a similar circuit a while back and it ran at several
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2013-08-02 Joule Thief, MOSFET Test
I built a Joule Thief using a 2N7000 MOSFET with the white LED across it, a standard coil (see below) and a voltage divider connected to the gate. I was trying to find out more about the MOSFET, such as the gate bias voltage needed to make it run on a 1.5V AA cell. The
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