Long Wave Radio reception 1600-1200 meter: selective HF FET antenna amplifier & filter schematic



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Please read the textbox & watch the video. A good setup of an antenna filter/front end (schematic with FET) to receive Long Wave radio signals. I used a FET to get the maximum selectivity + a “series type” antenna filter to remove rattle and noise during reception of the BBC and France on LW (in Europe).

Of course when you live in another continent the results may/can differ, anyway, the laws of physics and radio reception are also valid there.

Thanks to Rob, one of my YT followers,

Robs Channel is here https://www.youtube.com/channel/UCvWMllZR3-_JUAere7PwO_Q

Also this video where Rob receives radio stations with the help of a Arduino nano is very interesting
https://youtu.be/CoIpOIAL1Bw

He advised me to use a coax cable to transport the signal of the long wire antenna (7-8 meters blank wire in the garden) into the radio. To give it a better (more quiet) reception and shield off the noise etc. He has made an interesting video about SW radio reception.

That means also that the setup that I show here could only be working in such a case, with such an antenna setup (= 4 meter coax + a 8-10 meter blank wire hanging free, connected to the central electrode of the coax, the mantle goes to minus, ground in the radio). Though physics/radio laws are valid everywhere.

My idea is that especially the input filter plays a central role = 3.9 mH coil bridged with a 0-50 pF trimmer + a capacitor of 30 pF to ground. All connected via 18 pF to the gate of a small signal FET, the BF 256 A or BF 245 A,B, or C, watch the schematic of this so called “front end”.

Take in account: the antenna coil with that LW “single long wire” antenna (end in via the coax cable) for its most part does not receive the electromagnetic field of the radio signal on LW, but the electric field of the LW radio stations. To receive (in a better way) the electromagnetic part of these radio signals can/must be used. I have to do more experiments/study, anyway.

Corrections to the video:
1) When I disconnected my TL lamps on my workbench the BBC radio reception on LW was much better (!). They caused a lot of noise.
2) On 11.08 I say that I move the ferrite rod “out” but that is of course not true. I moved the ferrite rod “in” to get a higher inductance. Moving it “out” means less inductance.
3) On 15.08 I only mean that these 2 radio stations on LW (BBC and France) are transmitted out on different frequencies on LW, with a good frequency distance so that they can be discriminated properly by radio’s receiving the signals there.

Important: the trimmer (0-50 pF, paralleled to the 3.9 mH coil) turned completely “in” (= say 50 pF) means good reception of BBC. When this trimmer is turned out (say: 3-8 pF): good reception of the French radio station.

So a substantial effect on the selectivity of this tiny capacitive adaptation (!), test, try, align. NB: the reception results with this (type of, described) antenna are in Europe, location, the Netherlands, Utrecht. Though physics/radio laws don’t fail.

When you have questions about (certain analog) electronic circuits and how to make them: go to my Channel trailer (Radiofun232 on You Tube) and go to the “looking glass”. Type there the keywords that you want/need like: “power supply”, audio amplifier, capacitor tester, oscillator, radio, shortwave, shortwave radio, or any keyword you like to find the essential info & schematics on my YT channel.

Earlier relevant video’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

You can contact me via email when you have questions about my published circuits. I always ask for a picture of what you have made + a problem description; I ask to communicate.

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 electronics books are here:
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. Upload 14 november 2021.
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