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1500 questions
27
votes
4 answers

What is the relationship between SWR and receive performance?

If an antenna analyzer shows 1:1, does that mean it's an ideal receiver as well? And what about the converse, will a well performing receive antenna show a 1:1 SWR? I've wondered this for a while, sometimes I want a wide band antenna just for…
K9KRB
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4 answers

What is a link budget, and how do I make one?

Like the question title says, what is a radio link budget? For what is it useful, and how do I make one?
user
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2 answers

How do Handheld antennas work without ground?

Dipoles have the 2 wires going to each leg of the antenna completing the circuit. Big AM towers use the second wire as a ground plane But how do handheld rigs transmit and receive with just one wire sticking in the air?
Skyler 440
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3 answers

What is the body of knowledge the U.S. written exams test?

I'm considering getting a U.S. amateur radio operator license. If you want to study to pass a license test, there are many resources to learn the answers to the entirety of the question pool: online practice exams and study aids, “ham cram” courses,…
Kevin Reid AG6YO
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25
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3 answers

Why are some 1:1 current baluns twice as complicated as others?

I would like to add a balun/choke to my dipole for the reasons outlined in Using a balun with a resonant dipole. In the spirit of continued kit and/or DIY building for my ham shack, I set out to investigate how I might best proceed "from…
natevw - AF7TB
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25
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6 answers

How can I protect equipment against a lightning strike?

A lot of aerials (almost by design) would be rather good attractors of lightning. What steps do I need to take in the field to keep my gear safe against a lightning strike? I'm presuming the obvious already here (such as not operating in a storm),…
berry120
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1 answer

Is there a way to listen to live HF communications using the internet?

I'd like to be able to show people what a QSO sounds like without having my transceiver available. Is there a way I can listen to amateurs talking in real-time (or using Morse code) on the HF bands using my internet connection and the speakers on my…
dcaswell
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24
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2 answers

If I hear a distress call, what is the correct procedure for helping the person?

If during normal operation, I receive a mayday or pan-pan call, how should I handle this? Am I required to provide help in this situation, and what can I do to make sure I give all the assistance needed, what information should I try and get? If…
David VK2VXK
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24
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4 answers

What's the pinout for "Kenwood" 2.5mm TRS/3.5 mm TRS connector?

I've seen many Chinese HTs (Baofeng, Puxing, Wouxun, QuanSheng etc.) using the so-called "Kenwood connector", which has a 2.5 mm TRS connector and a 3.5 mm TRS connector. It looks something like this: I've seen it used for serial ports, speakers,…
AndrejaKo
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23
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2 answers

Why do we use LSB below 10 MHz and USB above 10 MHz when operating SSB HF?

As a relatively new ham operator, I understand that it is customary to use lower-sideband below 10 MHz and upper-side band above 10Mhz when operating single-sideband HF. I'm curious how we got to such a standard instead of just picking one or the…
BenSwayne
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23
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4 answers

How does the signal know where the cable ends and the antenna starts?

I know very little about antennas. I know, that for a certain frequency the antenna needs a certain lengths for good sending/receiving conditions. Often the antenna is at the end of a cable. Why doesn't the length of the cable count in addition to…
flux
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23
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2 answers

What makes a 5/8 wavelength vertical desirable?

An ordinary 1/4 wavelength vertical is smaller and resonant without any loading coil or matching network. What's the advantage to a 5/8 wavelength vertical? Why 5/8 in particular, and not something longer or shorter?
Phil Frost - W8II
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22
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3 answers

Can I build a radio telescope out of a parabolic TV satellite dish?

I have the possibility to buy a very inexpensive 2.4m parabolic satellite dish and I would like to build a radio telescope from it. Originally this dish was designed to be a satellite TV antenna. Can I replace the TV LNB with radio receiver tuned…
SP5RFD
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4 answers

I hate contests. How can I avoid them?

There's nothing worse to getting home, turning on the radio, and being unable to find a clear frequency that isn't full of a bunch of meaningless QSOs where somehow everyone is 599 and no one has anything to say. Are there any designated…
Phil Frost - W8II
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What information should be on a QSL card?

Like it says in the title. When you design a QSL card (intended for use for both local VHF-and-up contacts as well as international HF contacts), what information needs to be present, and what information might be considered "nice to have" but not…
user
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