Archive for April, 2017:

2017-04-27 Superregen FM BCB Receiver

I built this superregenerative FM broadcast band receiver today.  This circuit is similar to the one I posted on January 22. Here is a list of parts values I used: ANT – 12 cm insulated wire connected through 10 pF capacitor to FET source. C4 – two 2.2 nF MLCCs from + to ground plane (

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2017-04-23 Linear Power Supply Renovation 

In the past I’ve built several of these small power supplies to use around the house, and they come in handy.  But those others used a 12 VAC transformer instead of an AC adapter, so I had to add a fuse and other stuff to prevent shock.  Using the AC adapter is much more convenient

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2017-04-21 Signal Generator for 27 MHz

I need a source of signals on various frequencies to test how well my bandpass filters are aligned.  I built a Vackar Oscillator with tuning over a few CB channels, mainly 27.095 to 27.255 MHz.  These are radio control frequencies.  Like a Colpitts oscillator, the Vackar’s resonant circuit has two capacitors in series with the

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2017-04-20 27.145 MHz Transmitter And Receiver Pt 1

I’m trying to make a simple wireless alarm link.  The transmitter will be in an unheated garage, so the only way to easily get it to stay within the -+ 10kHz channel will be to use a XO (crystal oscillator).   But for the receiver, I figured the best way to go would be to

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2017-04-20 Buying SMTs From Newark Element14

I think I’m set for life when I need SMT transistors – I bought hundreds of them from Newark Element14.  They are having a discount sale; some of these transistors are discounted to less than 2 cents apiece whether you buy 1 or a thousand.  Some are as low as a penny – $0.011.  The discounted

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2017-04-17 Lost Blogs

I had problems with the blog and I had to reinstall the app.  All of the local copies got deleted from Jan 21 up until today.  I haven’t been able to do any blogging or moderate comments since Jan 21.

2017-04-18 The Exploded Transistor 

Someone said that you’re not a tech until you blow up a chip so violently that it imbeds itself into the ceiling.  Well, this transistor seems to have exploded violently.  It was inside a CFL bulb and when it went off, it probably wasn’t even heard.  It handled over a hundred volts, and it was

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