logo elektroda
logo elektroda
X
logo elektroda

Impedance transformer or antenna amplifier - what is the difference and which on

Jankesik 129677 40
ADVERTISEMENT
Treść została przetłumaczona polish » english Zobacz oryginalną wersję tematu
  • ADVERTISEMENT
  • #2 10387360
    irekr
    VIP Meritorious for electroda.pl
    The amplifier is most often equipped with a balun. Amplifiers should be used only where the signals are really weak and the transmitters are distant.
    The amplifier is not intended to correct the bad parameters of the antenna.
    If you live where you specified in the topic, then with a properly made antenna, the amplifier is unnecessary or even inadvisable.
    A balun must be installed.
  • #3 10387440
    Jankesik
    Level 25  
    The balun is not too expensive (about PLN 5)
    So I will buy an antenna with an amplifier. If the reception is too strong, I will remove the amplifier and install a balun. What do you think about it


    How do you think if you pick up TVP1 and TVP2 with this antenna
    Antenna: UHF Dipol 44 / 21-69 Tri Digit antenna
    location :D anniversaries
    The antenna is mounted on a 4-story block :P
    Cable length 25m
  • ADVERTISEMENT
  • #4 10387505
    rzeszutek1
    Level 19  
    The balun is used to match the impedance of the antenna to the impedance of the receiver, cable, etc. Let's say that the receiver has an antenna socket with an impedance of 75 Ohm, we use a coaxial cable with the same impedance, and we need to connect it to a dipole antenna with an impedance of 300 Ohm. We then need a balun between the antenna and the cable to match these impedances. In short, if the antenna has a different impedance from the receiver, first you need to mount an impedance transformer, and then, if necessary, amplify the signal with an amplifier. If there is no impedance matching of all components, distortions (signal reflection) and more are created, so there is no point in using an amplifier without first matching impedance with a balun. To sum up, always a balun, and then possibly an amplifier, or 2 in 1.
  • #5 10387575
    Jankesik
    Level 25  
    Is it possible to check the impedance of the receiver in advance? For example, if I give you a TV model
    Orion TV32FX500D
  • #6 10387662
    rzeszutek1
    Level 19  
    What is the socket? If the concentric is 75 OHM, if the two pins are 300 OHM.
    Hehe is brand new TV, so 75 OHM for sure
  • ADVERTISEMENT
  • #7 10387687
    matis057
    Level 33  
    Televisions from the '90s already have a 75 ? socket. Older TVs had a symmetrical 300 ?
  • #8 10387754
    Jankesik
    Level 25  
    So in the case of my TV, the symmetrizator will probably not be needed? And the antenna amplifier would rather be useful to me to receive TVP1 and TVP2
  • #9 10387768
    rzeszutek1
    Level 19  
    Exactly. In this particular case, you don't have to. Or rather, you need to buy a 75 OHM coaxial cable ;) .

    Added after 2 [minutes]:

    And whether the amplifier will be needed, it will turn out after assembly. If you have to, you can buy it later. The antenna has a very high gain, so you probably won't need an amplifier.
  • ADVERTISEMENT
  • #11 10388099
    Anonymous
    Level 1  
  • #12 10388112
    rzeszutek1
    Level 19  
    Jankesik wrote:
    I need about 27m. Do I lose quality with such a long cable?
    Each cable, apart from weakening the signal, will cause some distortions, because it is not a perfect waveguide (there will be some reflections, etc.), but there is probably no other option, so there is no need to think about this topic. I would rather be worried about the drop in signal level.
  • #14 10388463
    Anonymous
    Level 1  
  • #15 10388468
    matis057
    Level 33  
    Moment...
    If the colleague has nothing in the antenna box, then a balun must be installed.
    If the signal is too weak, the amplifier and antenna power supply will be needed.
  • #16 10388622
    Jankesik
    Level 25  
    Okay, let's put it all together
    If the signal is too weak, I install an antenna amplifier
    On the other hand, if the signal is fine, I mount the simulator without the amplifier
    Do I have to assemble this symmetizer in case of good reception?



    I think right or not
  • #17 10388642
    rzeszutek1
    Level 19  
    If we are talking about this specific case, then an additional impedance transformer is not used here, because all elements have an impedance of 75 Ohm - such a balun is already in the box. However, if the signal is too weak, you will have to buy an amplifier. Amen ;)
  • #18 10388727
    Jankesik
    Level 25  
    So I have to understand if the reception is ok, I do not put anything in the antenna box


    Okay, 1 last question. Is this antenna amplifier ok for this antenna
    Impedance transformer or antenna amplifier - what is the difference and which on
  • #19 10388790
    rzeszutek1
    Level 19  
    You understand well. However, the amplifier itself is not suitable. As you can see, it is adapted to an antenna with an impedance of 300 OHM (so it includes a balun). Here you will need an amplifier with I / O at 75 Ohm (for short, concentric terminals on both sides).
  • #20 10388793
    Anonymous
    Anonymous  
  • #21 10388810
    rzeszutek1
    Level 19  
    On the other hand, a balun is already installed in this antenna box.
  • #22 10388811
    Jankesik
    Level 25  
    Gentlemen, I am asking someone for a final answer. What should I install in this box? And will the photo of the amplifier I gave above fit?
  • #23 10388818
    Anonymous
    Anonymous  
  • #24 10388823
    rzeszutek1
    Level 19  
    mihal2002 wrote:
    What's this nonsense? Do you know what you are writing about?
    A friend wants to buy a symmetrizator. The antenna, on the other hand, has an impedance of 75 Ohm, so as I wrote above, it is already in the box.
  • #25 10388824
    Anonymous
    Anonymous  
  • #28 10389989
    Jankesik
    Level 25  
    I close the topic because a few people have caused confusion and chaos here
  • #29 20096275
    G.R.
    Level 17  
    rzeszutek1 wrote:
    The balun is used to match the impedance of the antenna to the impedance of the receiver, cable, etc. Let's say that the receiver has an antenna socket with an impedance of 75 Ohm, we use a coaxial cable with the same impedance, and we need to connect it to a dipole antenna with an impedance of 300 Ohm. We then need a balun between the antenna and the cable to match these impedances. In short, if the antenna has a different impedance from the receiver, first you need to mount an impedance transformer, and then, if necessary, amplify the signal with an amplifier. If there is no impedance matching of all components, distortions (signal reflection) and more are created, so there is no point in using an amplifier without first matching impedance with a balun. To sum up, always a balun, and then possibly an amplifier, or 2 in 1.

    And how does it relate to the BiQuad antenna, what do you need an amplifier or a balun?
  • #30 20096847
    irekr
    VIP Meritorious for electroda.pl
    Each amplifier - except amplifiers for logarithmic antennas - has a balun.
    There is an impedance problem with BiQuad antennas as these antennas have a resistance of 50 to 90 ohms depending on the design. A compromise solution is to use a balun from ASR "Telmora" antennas, which have a 1: 1 ratio (75 ohms symmetrical to 75 ohms unbalanced).

    The amplifier is used only where absolutely necessary. DVB-T2 tuners and decoders in receivers have a very high sensitivity, sometimes even too high.

    I ignore the problem of the quality of these amplifiers, not meeting the requirements.

Topic summary

The discussion revolves around the differences between impedance transformers (baluns) and antenna amplifiers, particularly in the context of improving TV reception. A balun is essential for matching the impedance of the antenna (often 300 Ohm) to the receiver (75 Ohm), preventing signal distortion. Amplifiers should only be used when signals are weak and not to compensate for poor antenna performance. Users discuss the necessity of a balun in their setups, with recommendations for specific antennas and cables. The consensus is that if the signal is adequate, an amplifier may not be needed, and a 75 Ohm coaxial cable should be used. The importance of using the correct components to avoid signal loss and distortion is emphasized.
Summary generated by the language model.
ADVERTISEMENT