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Regarding the earlier “easy Radio” (published 17 dec 2022) I did 2 adaptations to get the noise under control. Noise is generated by: the HF amplifier (BF 245 a FET and BF 199 NPN with a Hfe of 70 it is a Si transistor), by the other NPN transistors (2 x BC 547 b, NPN, Si transistors, both have a Hfe of 300).
And of course by the whole “setup”: an indoor antenna in a home situation with manmade noise by all kinds of electric/electronic devices. Apart from noise sources outside the living room: electric trams, etc. These latter things are in my case not there, by the way.
Anyway: the video shows a quite successful noise reduction for the audio amplifier (here a LM 386 N-1), specially working in combination with a (read: that) shortwave radio. The 10 mH (MilliHenry) coil in the lead to the loudspeaker does that job.
Links to the preceding video’s (easy SW radio, demo) are here:
• Listening 22 dec 2022 ... (listening in the night, Netherlands, location Utrecht, to eastern Europe radio stations 22 Dec. 2022)
And: • VLOG Few transistor SW... (first demo of that Radio, same date: 22 Dec. 2022)
I will publish the circuit asap. It needs perhaps some elaborations, I want to make it as reproducable as possible for everyone interested in radio things. So want to get to the best stabilized circuit. Thanks for watching.
Please note: these good reception results happen, in general, during the night on the location where I live in the Netherlands. In other situations where you live on earth you will surely hear other SW Radio Stations, perhaps from South America, China, Eastern pacific radio stations, etc.
During the day it could be that you cannot receive anything (!!) on (these) Shortwave frequencies. Has to do with radio propagation on Shortwave, the sunspot cycle (every say 8 or 11 years or so).
So some SW radio bands can be closed during the day, night, certain parts of the day, certain parts of the night, or even for a certain (longer) period (sunspot cycle), say months or years. In these periods radio reception on certain SW radio bands could be (very) problematic. More info? Go to radio amateurs or study radio amateurs websites (all over the world) on “propagation”.
My You Tube channel trailer is here: • Radiofun232 on KZfaq... 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.
www.lulu.com/search?adult_aud...
I keep all my YT videos constant actual, so the original video’s with the most recent information are always on KZfaq. 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 23 December 2022.