Trying to make a Long Wave Radio pt 5: universal Local oscillator for 951KC-1.3 MC or for Shortwave

Please read the textbox first. Video 5 In the process of trying to make a Long Wave Radio between 150 KHz and 280 KC.

My first idea was to make a converter. In that case you need a local oscillator and a mixer. Both units were showed in my earlier videos.

But, after all, the first idea/good thing is to make a so called “front end” (= the first antenna stage with in many cases a HF pre-amplifier) that is especially made to receive the electromagnetic spectrum in this frequency band, 150 KC-280 KC.

That means: a high quality ferrite coil or a loop antenna. I will not focus on the loop antenna, because it is/will too big and/or is not practical. I want to keep it simple by trying to make a Long Wave radio coil on a ferrite rod, perhaps combined with an indoor antenna. Not with litze wire (to expensive & too scarce) but with say “normal” laquered copper wire of (say) 0,4 mm or 0.5 mm.

Anyway & after all: this video shows a Local Oscillator (or a so called VFO = variable frequency oscillator) that works (in this case) between 951 KC and 1.3 MC.

It has a very pure sine wave, works good with the FET BF 256 A. You can surely get to higher oscillator frequencies by changing the inductance of the coil and/or the value of the parallel capacitor (now 500 pF, for SW it will be in the 10 pF-150 pF range). Idea: 1 MC-12 MC sine waves can be generated.

Very important: the capacitive voltage divider in the oscillator has to be changed, when you want to go to higher frequencies (say on Shortwave, from 2 MC-16 MC).

Thus: very important: change the 1000 pF capacitor (gate-source) in this schematic to another value when you want to go to higher frequencies. You want to go to 2 MC-12 MC or even 16 MC?

In that case use a 220 PF for the capacitor between the FET Gate and the Source and a 100 PF between the FET Source and the Ground (-) minus.

Test/try/experiment! Always good.

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.

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.

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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 cannot help that these things happen. Upload 24 october 2021.