Merry Christmas everyone!

We live 22 december 2021, at least in the Netherlands. For everyone liking to do studies here is a first explaining video about an earlier transistor setup on my YT channel.

It is [ Ссылка ]

But better: most important links to video’s where I have showed to make a 2 transistor multivibrator with coils that determine their frequency is here:

Video link
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First video 22 oktober 2020 regarding that subject is here
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Next video (11 november 2020) regarding that subject is here
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Other, but less relevant links to videos that have made, in a certain way regarding the subject published now, 22 december 2021, are here:

Video link
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sine wave oscillators tunable via only 1 potentiometer
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And: [ Ссылка ]

Please read the textbox. This is a kind of a “first sight” video, where I am looking on old radio transistor books of the 1950’s-1960’s to 1990's on the website of worldradiohistorydotcom.

Thanks to Barry Blod, he told me of this website where I find every day since then my inspiration for making YT video’s.

Important: on 9.58 I say that it is a L-C circuit, but of course it is a kind of R-C circuit where a tank circuit (=LC circuit) is used in a kind of combination.

Important corrections to the video:
1. 6.43. The circuit on 6.43 is not clear. Are the 2 cathodes of the 2 diodes connected together? Test/change & try it out. I am almost sure that the “upper diode” is not connected to the wire, so not connected to the collector of transistor 1 (like diode 1), but goes directly to the collector of transistor 2. Always a problem when searching “historic” schematics….(sorry). Testing is necessary or good quality electronics studying at first about this problem, afterwards: a simple test that will reveal/confirm.

2. On 9.27: it is not sure that this can work. Shortcut effects? Study radio/electronics theory and better: do experiments to get it working. Given the circuit the tank circuit (L-C) can shortcut the good properties of the multivibrator (?). Again: test and try. The triode tube circuit is in electronics terms not comparable because of its high impedance circuit on the tube grid.

3. 12.00. The old 1960’s two transistor free running multivibrator circuit talks about PNP transistors. No problems with that. For NPN transistors with its emitter on the negative node: use (say) the BC 547 B NPN and reverse (+) and (-).

This A stabile multivibrator will also work properly with NPN transistors, say 2 X a BC 547 b. Of course don’t solder the wires on “X” together....

4. These old books on this website often refer to Germanium transistors, I have tried (and successfully) to translate some of these Germanium circuits to circuits where Silicon transistors are/can be used.

Perhaps this video is afterwards quite “sloppy”, because I could not find a direct circuit (in the book) to compare it to the properties that were showed in comparable electronic (1 or 2 transistor) circuits on my You Tube channel, say the multivibrator,s etc.

Anyway: these old (but never old) circuits show working essentials.

My You Tube channel trailer is here: [ Ссылка ] When you search, search always “NEWEST FIRST” to get the right overview. You can also search via the “looking glass” on my Channel trailer via keywords like ”audio”, “radio”, “amplifier”, “filter”, “Shortwave”, “transistor”, “FET”, “oscillator”, “generator”, “switch”, “schmitt trigger” etc; so the electronic subject you are interested in. My books about electronics & analog radio technology are available via the website of "LULU”, search for author “Ko Tilman” there.

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I keep all my YT videos constant actual, so the original video’s with the most recent information are always on YouTube. Search there, and avoid my circuits that are republished, re-arranged, re-edited on other websites, giving not probable re-wiring, etc. Some persons try to find gold via my circuits. I take distance from all these fake claims. I can not help that these things happen. Upload 22 december 2021.

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