From FB group Building Transistor Radios Mar 20 Bob Kirsch Any recommendation for doing a complete alignment? Documents? I used a HP sweep gen decades ago but I don’t have one now, just an old signal gen. I thought about building a sweep gen but I need to get a few parts. I have bought
(Read More…)
From FB group Building Transistor Radios 2019-03-19 John Ferguson Yeah, I used to use the Sylvania ECG and the NTE catalogs to cross-reference transistors. But then I got some better product manuals from the makers, especially Motorola and National Semi. And I got hold of the professional industry documents. ECG and NTE give a ‘one
(Read More…)
Something that should be memorized by every technician. This also applies to capacitors in series.
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.
(Read More…)
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
(Read More…)
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.
This is my answer to a question on Facebook about what movie have you watched five or more times. I think I watched UP! more than once. And Wall-e. But I can’t see spending that much time watching a movie when I know pretty much how it’s going to be after the second or 3rd
(Read More…)
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
(Read More…)
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
(Read More…)
