# Tag Info

5

"IQ" refers to the practice of having two mixers with their oscillator phase 90 degrees apart, and then the digitization and processing of those two streams of data. One practical problem is in a superheterodyne receiver, the LO must be selected and the filters designed for the best image response. The problem can be understood intuitively like this: say ...

4

That was just added by someone who's primary language probably isn't English. What they meant to say is "QPSK31, a mode that is related to PSK31, uses..." Other than that, the claim "it uses more constellation points, that's a means error-correction coding", is plain wrong. The error coding used is this, just one sentence later: A ...

4

To just answer the literal question: I stands for Inphase and Q stands for quadrature. These are the two baseband signals you get when you mix the RF signal with a cosine of the carrier frequency, and with a 90° shifted version of that cosine, respectively (and properly low-pass filter afterwards). We call the first the inphase component, because it is ...

4

Frequency and wavelength of a wave are related: the frequency times the wavelength equals the speed of the wave, in this case the speed of light. For HF, the frequency in megahertz times the wavelength in meters equals 300. Modern radios display the frequency. Bands are referred to by their approximate wavelength for historical reasons. If the frequency ...

3

If you are a new ham, you need to go to the https://arrl.org web site and get a listing of the ham bands that they publish. You can find them on their site by searching for ham bands. Print out one of the listings; the 8.5 by 11 inch chart is in color. They also have some that are able to be printed in black and white. On those charts, it lists that you with ...

3

Modern radios that have RIT and XIT typically also have a button that you can use to listen on your transmit frequency. This means that if you use XIT or RIT, then you can listen on your transmit frequency (rather than on your receive frequency) to check conditions on there. The typical use case for RIT is if you are calling CQ and you start to get a pileup, ...

3

There's really not a upper or lower limit to price -- it entirely depends on what capabilities you want. At the low end, you can get a receive only SDR for $20; several suggestions can be found at rtl-sdr.com There are several hand held UHF/VHF tranceivers available for under$50. The quality of these are questionable, but they usually last at least 2 ...

3

"E-power" is probably an abbreviation for "emergency power", meaning that the repeater is able to function (for some amount of time) even if grid power to the repeater site fails. A "link" is when two repeaters are connected (over radio, internet, or phone) so that they repeat transmissions heard by either repeater, thus having a larger coverage area or ...

2

In this case, "allied mode" can be replace with "associated mode" or "kindred mode." The phrase indicates that there is a relationship between the two modes, BPSK and QPSK, without specifying the particulars of the relationship. "Allied mode" is not meant to convey or identify any specific technical content.

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If you were designing a link budget, EIS is the minimum power required at the receiver, assuming the receiver is an ideal isotropic receiver. The EIS encapsulates the effects of both the receiver's sensitivity and antenna system. A link budget might look like this: transmitter power +/- adjustment due to antenna mismatch - transmitter feedline loss + ...

2

RIT means that your VFO frequency will be offset from your dial frequency (usually by a relatively small amount) while you are receiving. XIT means that your VFO frequency will be offset from your dial frequency while you are transmitting. So a dial frequency of 7125 kHz and a RIT of +1000Hz will accomplish exactly the same thing as a dial frequency of 7126 ...

1

While most modern radios are vary accurate in regards to frequency, not all radios are. Our signals get garbled with the transmitting frequency of one radio is not the same as the receiving frequency of the other. By slightly adjusting the receiver frequency with RIT, you can sometimes get better reception of a station that is transmitting slightly off ...

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Financially, \$100 isn't out of the question. For the technician part of my own experience: I paid about \$25 for a Technician study guide (also available on Amazon) which might be helpful if one of the free options doesn't give enough background It usually costs just \\$15 for each exam attempt, which includes the license application fee too assuming you ...

1

A Fourier series can represent a real-world signal as a weighted sum of harmonically-related sine and cosine waves. Sine and cosine waves are out of phase by one-quarter of a cycle and so are said to be in quadrature to each other. Thus, the weighted sums are known as the In-phase (I) and Quadrature (Q) components. For example, single sideband modulation (...

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If you're looking for just a basic definition, I/Q data is the result of a special form of sampling. Unlike "normal" sampling which takes a single measurement of a signal at each division of the sample rate, I/Q sampling gathers two measurements for each sample: both an "In phase" and a "Quadrature" component — thus the acronym. The "quadrature" part only ...

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