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I have a number of books on antennas and without exception they all describe balancing antennas only for transmission. Since I do not even own any transmitters these guides are useless.

I have only receivers. How do I tune an antenna for receiving? Mostly I am interested in the VHF frequencies, but also UHF sometimes.

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  • \$\begingroup\$ You may get some better answers over at ham.stackexchange.com, in fact if you search there, there are several questions you may find relevant already. Many of those are regarding HF antennas, but if you scale such antennas down the same theory applies. At VHF/UHF frequencies it gets simpler due to smaller space needed and more easily improved wire diameter vs. wavelength ratio. It's also more practical at these frequencies to implement broadband antennas like the discone and log periodic arrays which require less tuning anyway. \$\endgroup\$ – natevw Mar 11 '16 at 18:30
  • \$\begingroup\$ Also, can you clarify what you mean by "tuning"? There are at least two meanings I could see in this context. Adjusting the physical dimensions of the antenna towards a desired result is what I think of from "tuning an antenna". But adjusting the electrical resonance, or improving an impedance match through a so-called "antenna tuner" may also be what you mean? (Generally when receiving, the latter simultaneously increases the signal AND noise, and most receivers can already achieve that just fine themselves through their own gain circuitry if it's not overloaded.) \$\endgroup\$ – natevw Mar 11 '16 at 18:40
  • \$\begingroup\$ What natevw said. Don't be put off by the site name Amateur Radio; questions relating to radio theory are welcome, even if they aren't strictly about amateur radio. See the Amateur Radio SE on-topic page. Antenna design questions are specifically listed as on topic. \$\endgroup\$ – a CVn Mar 11 '16 at 23:11
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An antenna can be as simple as a piece of wire (quarter wave monopole for instance or a half wave dipole for another example): -

enter image description here

The monopole (for instance) will receive any frequency but is inherently better at producing a stronger signal at one particular frequency and, as the name suggests, this frequency is at a quarter wavelength of the RF wave to be received.

So if trying to receive 300 MHz (wavelength 1m) you need a quarter wave monopole that is approximately 25 cm long. It will have a usable bandwidth (i.e. not require a retune) of probably 50 MHz (poor groundplane) to over 100 MHz (good groundplane). At the extremes the receive signal will be noticeably weaker but not necessarily unusable.

Think about commercial FM - it uses a monopole and tunes easily 88 to 108 MHz (20 MHz) with a centre frequency of 98 MHz.

This isn't true of a transmit antenna because the VSWR will be significantly worsened at extreme frequencies and power delivered to the antenna might be very small and may even damage the electronics driving the antenna.

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  • \$\begingroup\$ This is good, since you address tuning the antenna itself. My answer was using impedance matching to the receiver. \$\endgroup\$ – Marla Mar 11 '16 at 17:32
  • \$\begingroup\$ @TylerDurden did I answer your question? Do you have anything else to ask? Have you considered accepting an answer to this question? \$\endgroup\$ – Andy aka Feb 21 '17 at 18:25
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Not sure if you are seeking information on balancing or tuning of an antenna.

Balancing an antenna (or rather the transmission line) (taken from This post :

Unbalanced Lines. What happens when the currents on a transmission line are not equal? In the case of a parallel transmission line, the electromagnetic fields around the conductors will not be the same and will not cancel, so radiation from the transmission line occurs.

Thus, balancing an antenna system is not as important on a receiver as on a transmitter.

Tuning (impedance matching) of antenna to transmission line, and then to the receiver impedance (which I suspect you already know) is different from balancing.

I have an antenna tuner that I use. I simply adjust the antenna tuner to obtain maximum signal strength. Which of course doesn't guarantee an impedance match, but does the best I can with the limited resources.

Simple Tuner :
enter image description here

In your EDIT, you have focused in on "tuning".

Given that you might know your antenna impedance and receiver input impedance, a Smith Chart is very helpful and avoids mathematical calculations.
Plot the antenna impedance and receiver impedance on the chart. Then there are many many ways to use reactive components to transform impedance of one to the other.

Smith Chart Information describes Smith Chart better than I can.

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  • \$\begingroup\$ No, tuning is what I want, not balancing (I edited my post). The diagram you give shows the antenna on the output side. I am wanting to tune an antenna for receiving only. \$\endgroup\$ – Tyler Durden Mar 11 '16 at 16:22
  • \$\begingroup\$ @TylerDurden : The antenna tuner is symmetrical, you can use input/output either way. I have added information about Smith Chart to my answer. \$\endgroup\$ – Marla Mar 11 '16 at 16:26
  • \$\begingroup\$ One aspect of the problem is that from what I understand it can be difficult to determine the impedance of a receiver because it requires a "network analyzer" which is very expensive. \$\endgroup\$ – Tyler Durden Mar 11 '16 at 16:30
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Sounds like you might need an absorption wavemeter (or 'dip meter'). This generates a low power RF signal that is loosely coupled to the antenna (or any other tuned circuit); you then tune the wavemeter's frequency and look for a dip on the meter which indicates resonance.

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Generally, transmitters only transmit at one frequency (or a limited bandwidth in the case of FM) and in this case it makes sense to tune the antenna so as to maximize power output.

Receivers, on the other hand, usually operate over a fairly wide band, and their antenna cannot be tuned as precisely as transmitters. In this case, the antenna is designed for good coupling in the receiver's band, but no more effort makes sense.

If a receiver is to be used at only one frequency, then by all means tune the antenna. The procedure is exactly the same as for a transmitter.

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    \$\begingroup\$ Unless the procedure to be followed says "transmit and tune for minimum SWR." \$\endgroup\$ – JRE Mar 11 '16 at 15:47
  • \$\begingroup\$ I cannot use "the same" procedure because I DO NOT HAVE A TRANSMITTER as I said. \$\endgroup\$ – Tyler Durden Mar 11 '16 at 16:17
  • \$\begingroup\$ @TylerDurden you don't need to have a transmitter to follow the same procedure as used for a transmitting antenna - the procedure is the same for both receiver and transmitter. \$\endgroup\$ – Andy aka Mar 11 '16 at 16:55

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