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Trying to make a simple LW radio TRF part 9: receiving the BBC and France with too much noise VLOG



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Please read the description. Only a VLOG, where I tell some experiences, part 9 of the series (when I count all my side paths), where I try to make a Long Wave radio that has to work between 150 KC and 280 KC.

The setup that was earlier published (video 4, link below) worked very good on AM (700 KC-1.6 MC) but it was very difficult to find the right antenna coil for Long Wave, say 1750 to 1287 Meters.

Reason is that I use it with a long wire antenna (10 meter) outside, so no focus on the magnetic part of the radio wave. That focus (radio reception principle) is in general used to receive Long Wave radio stations, so a ferrite antenna (ferroceptor) is used that is direction sensitive.

It will perhaps be a second development/experiment to get that worked out, will take time, anyway. I tested many coils (video), tested the superheterodyne setup, made side paths (did not want to work good), finally got back to the TRF principle.

Found that a coil out of a electronic organ of the 1970’s (sine wave oscillator) could work as an antenna tank circuit for Long Wave reception, it was tested at 1 milliHenry.

Second idea was: go to one of my factory made test coils that I have, used one of 3.9 MilliHenry and it worked kind of acceptable (lot of noise, but at the moment the best results) in combination with a 500 pF tuning capacitor (schematic) + a long wire outdoor antenna (10 meters).

But, of course, this is the Long Wave Radio band and the antenna plays a big role in proper radio reception. When it “loads” the resonance frequency of the antenna coil (tank circuit) (or say the antenna coupling capacitor has a too high value) the antenna “forces” the tank circuit down to a lower frequency and you receive nothing, or radio stations on another frequency, not the frequency that you aim.

So the antenna must be “tuned” here to VLF, that is in its easiest way done by choosing the right value of the antenna capacitor that connects the 10 meter wire to the tank circuit.

With a low value antenna capacitor (here 33 pF) the 10 meter antenna wire is “loosely” coupled to the tank circuit (antenna coil) so that the antenna coil keeps its good resonance properties and tuning is possible. If not: tuning to the wanted radio stations does not succeed.

Earlier relevant video’s (there are some more in this series):
Video 1 (first idea’s) https://youtu.be/flH--5q7zbw
Video 3 (impedance transformation radio circuits with a FET, second idea) https://youtu.be/vSPQGG4qol8
Video 4 (most important) very good practical 2 transistor TRF setup for AM https://youtu.be/9XK3nGlFQdk

Also side paths when trying to make the superheterodyne setup for Long Wave, proved to be not very succesful, needs more study & experiments:
Radio mixer circuit https://youtu.be/L7-aoGWQdCk
455 ceramic filter test (part 8) on its bandwidth https://youtu.be/6h9fbAo-vtI
Searching a good quality Germanium radio detection diode https://youtu.be/AmcaMFdrLPc

There are approx. 1200 video’s on my YT channel with many electronic subjects.

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 9 november 2021.
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