VLOG about radio technology of the 1920s and the 1950s: loop antenna & IF coils & capacitors & more

Please read the description first. Much more info is there & valuable links to other schematics that are relevant.

A blogvlog about radio technology of the 1920s and 1950’s talking about:

1. LOOP antenna’s

2. IF coil filters (on 455 or so Kilocycles, how they were made and how they work, via e.m. coupling between two small kind of flat honeycomb coils on a frequency in the range of 455 or so KC)

3. About preventing “crack noises” in volume control circuits with classical (carbon) potentiometers. The 1951 book tells about radio tubes, it also refers to classical audio amplifiers, now, 2023, made with bipolar transistor: prevent DC flowing into the base of such a transistor in audio setups by using separation capacitors, for audio in the 0,47 uF (non polar) to the 3.3 uF (non polar) range.

4. About capacitors and a very old capacitor tester of the 1950’s.

Correction/remark: the book “Handboek der Radiotechniek (translation: “Handbook of radio technology”) is from 1951. I was somewhat unsure about that date (first part of the video).

And on 8.33 in this video I talk about a "ceramic filter of 10.7 KC", of course I mean: 10.7 MC = Mega cycles, (sorry).

The book of mr. Corver, named (in Dutch) “Het Radio Amateur Station” (there are two parts, by the way, part I and part II) is from (approx.) 1926-1929. Part II of this book is surely from 1929. It is written in that book.

Thus from the days that the triode radio tube was in a certain way in common use, used as amplifier, oscillator, and radio detector of Amplitude Modulated signals. Philips (Netherlands) produced the triode radio tube for its first on 1918 for the public.

The easy and simple capacitor tester schematic + demo to be used with a frequency counter is here:

https://youtu.be/1rCxqLe2U0U?si=Txz40WcskV1fzMPB

A capacitor tester for 2 pF-1.5 uF (the "box" that I show in this video) is here:

https://youtu.be/etEfoHZAmww?si=9qIeRLnRn1EyVmH9

There is also a video about home-brewing coil types IF filters on 450 KC (or in that range, 440-465 ) on my YouTube channel. I used these home brew 450 KC IF filters in practice in the past in an AM radio that worked between 800 KC and 1.6 MC (the classical AM radio band).

In the Netherlands, by the way, this AM band is in a kind of way “dead”. Only a few small power local radio stations operated by particulars are there now, say in the region of Rotterdam and Utrecht.

Home brew IF coil filters (video) between 450 and 465 KC is here:
https://youtu.be/NRuuwtA6A64

Mixer circuit with 455 KC ceramic filters (modern solution) is here:
https://youtu.be/M9HRwDvFI54

My You Tube channel trailer is here: https://youtu.be/xbgQ8T3oqh4

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.

https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=Ko+Tilman

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 cannot help that these things happen. Upload 29 October 2023.

Sorry for the sometimes somewhat “shaking” in this video.
With a wobbulator you can test the bandwidth of a homebrew IF filter, with two flat coils (honeycomb or not) on their properties: passband, effects on frequencies below and higher than the passband, etc. It is showed in the earlier mentioned video, link is

https://youtu.be/NRuuwtA6A64

Always enjoying experiments to make a good superheterodyne radio receiver!
29 Okt 2023

Видео VLOG about radio technology of the 1920s and the 1950s: loop antenna & IF coils & capacitors & more канала radiofun232