Radio communication paths can be noisy, they can suffer interference from other transmissions or electrical noises, they’re narrow band (remember I said only a small range of the voice frequencies are transmitted) and the person you’re talking to may not share the same native language. This isn’t like talking on the phone where you can clearly hear the other person including when they laugh, mumble, gasp and whisper. It’s possible that you may only be able to hear one side of the conversation if the second station is not also in range of the WebSDR receiver.Ī big part of Amateur Radio is the self-training in radio communications. This is because we’re using a single frequency and you are either transmitting or receiving…if you’ve ever used a walkie talkie or CB you’ll have experienced this. The width of the signal in the waterfall depends a little on the transmission…here the station on the left has someone talking and the station on the right is playing music.įirst things first, the conversation you’re listening to now is what we call simplex which means only one person can talk at a time. In the image below we can see two stations one centred on 7285kHz and one at 7300kHz. The width of the bright line scrolling up the waterfall should be similar to the width of the yellow tuning indicator. To tune into a station move the yellow tuning marker until it is centred on the transmission (the bright vertical band). In the frequency range indicated by the purple zone (41m broadcast) you should see several bright vertical bands on the waterfall. This represents the bandwidth of the received signal. Check it out, select LSB then AM and see the difference. You may have noticed that when you selected the AM button the yellow tuning indicator got much wider. If you do this simply press the AM button again to reset the size of the tuning indicator). Other distinguishing features of antenna tuners are weather resistance, the type of antenna connection (wire or coax), and the circuit design (L-element, Pi-element) etc.If you’re not already able to hear a station reasonably clearly try dragging the yellow tuning indicator left and right or use the +++ & - tuning controls in ❸ (note, if you try dragging the yellow tuning indicator and it simply gets wider it’s because you’ve grabbed the wrong bit! Try and click on the top edge of it and not the sides. This usually makes operation much easier. Important for automatic tuners is the possibility to connect the tuner directly to the transceiver with a cable that fits exactly. Therefore external tuners are usually superior - they have a larger impedance range in which mismatching can be compensated. However, there is usually not much space available for large capacitors and coils. Most built-in antenna tuners also work according to this method. The more such components a tuner has, the more precisely it can achieve precise matching. The disadvantage is the time-consuming, manual operation.Īutomatic antenna tuners tune automatically on demand, mostly with a relay network different fixed capacitors and inductors are switched through. Manual tuners have the advantage to be tuned very precisely and to be designed for high power. Manually tuned matchers are those that are equipped with variable capacitors and coils, which are then changed by hand to compensate for the reactive components of the matching. You must compensate for capacitive or inductive mismatch, depending on how the antenna is constructed.Ī distinction is made between manually and automatically tuned antenna tuners. An antenna tuner solves this problem by matching the impedance of the antenna to the impedance of the transmitter. And so the transmitter can't transmit all its power to the antenna, it is converted into heat loss. Most of the time the resonance is not quite right, with the result that the standing wave ratio which the transmitter 'sees' is not very good. Losses, non-optimal space and many other circumstances prevent you from always being able to use an ideally matched antenna. Frequency Counter, Near Field Receivers.Morse keys, electronic keyers, accessories.Stationary, directional antennas (Yagi, X-Quad).
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