![]() ![]() The power is supplied over the coax cable, from the power supply to the antenna pcb, the signal is decoupled from the power line via a choke coil.Īlthough it is also possible without (flying setup), it is best to make a small print. The main task of this 2nd transistor is to form a high/low impedance converter with the coax cable to the receiver. Is an old VHF RF transistor, which was used in cable TV amplifiers.Īnother good HF/VHF transistor is also good (eg 2N5109), as long as it can draw around 110mA emitter current. The next stage with a transistor, type TRW80181, This is also a low noise transistor amplifier. J310, which has a very small input capacitance of about 2pF. This copper pad is coupled to a J-FET Type No. This picture represents a capacitance of about 3 to 5pF, and is single-sided. The actual antenna is a copper plate of at least about 3x4 cm. The schedule is as you can find many on the internet. So I made a PCB design with a PCB design program,Īnd later also drew a schematic in there, and after that the PCB result was printed, and a PCB was made of it.Ĭlick on the drawing for a larger version ![]() I thought, let's get it right right away. More on this later.īut yes, I had now started building my own antenna, a "Mini-Whip". The electrical interference radiation indoors is simply too strong these days. Let me put it this way: this whip antenna no longer works indoors these days. I didn't really know how it worked at the time, and hadn't heard of any malfunctions in the house at the time.Īfter it was exactly recreated according to Elektor, it didn't work very well either.Ĭonclusion: you must have seen some of the theory of the Mini-Whip to understand it. That wasn't really a success, and the whole thing ended up in the junk box. With which you could make an active (indoor) antenna, with a sliding blade. In the "Slim Line" version, elsewhere on the site, this is less the case.Ībout 30 years ago, there was once a free print from Elektor, In this article you will read some more insights and techniques. Kind of antennas were rather disappointing. Since it is an active antenna, I was quite skeptical, because my previous experiences in this The boys from the Dutch Unief Twente also use this antenna for their Web-SDR. I came across this Mini-Whip from maker PA0RDT, which can be found in many variations. Test of a basic Mini Whip antenna (PA0RDT) for HF Frequencies from 10kHz to 30MHzĪfter an intense search on the Internet for a simple antenna for HF-SDR reception (10kHz-30MHz), Update 2021: New techniques, new insights Klik hier voor NL versie De eerste Mini Whip antenne in UBA-SNW ? ![]()
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