These are scans of the specifications for most of the Motorola HEP line of replacement transistors. Germanium and Silicon. Pages 10, 11, 12.
2018-09-02 Mims Mistakes In Audio Amplifier
From FB group Building Transistor Radios, 2018-09-02 I already see one mistake. On p.27, Audio Mixer. The R6 is only 1k. The voltage divider R5 and R6 will give a voltage less than 0.6 at Q1’s base, which means Q1 will not be forward biased enough and the circuit won’t work or else sound distorted.
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2017-06-08 AD Has ADP5090
Ever since I’ve been experimenting with Joule Thiefs I’ve done so with the intention of using the circuit for boosting a low voltage source to power a higher voltage circuit. So I think this Analog Devices ADP5090 is very useful for doing just that: powering circuits up to 200 mW from very low voltage power
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2017-01-04 ASCII Chart
I tried posting this on Facebutt, but it thinks this single image .GIF is a movie! So I’m putting it where all can get it.
2013-05-03 Ohm’s Law Chart
This is a chart for everyone, even though you should already know it.
2012-12-26 Lossev’s Crystal Oscillator Experiments
I was looking through the Yahoo group lost_technology and came across an article from the Wireless World, 1923 about the Russian O. Lossev’s experiments with crystals (the mineral kind like those used in detectors). He got best results with zincite and a carbon or steel whisker. I have a galena crystal, but he got poor
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2012-05-09 Small, Medium Signal Amps – talkingelectronics.com
I came across this column in talkingelectronics.com where the author discusses small signal and medium signal amplifiers. This medium signal term is one that I’ve never heard used before, and I’ve read a lot of literature that uses the small and large signal terms. I’ve heard the small signal term applied when an incremental term
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2012-04-05 Choosing Diodes for Joule Thiefs
Note (from yesterday’s blog): I have seen many good Joule Thief projects mistakenly use the 1N4003 series rectifier, which is made for 50 or 60 Hz, and has a slow recovery time. I have put a 1N4003 in parallel with a 1N4148, and found that the Joule Thief’s performance often drops. This is because it
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