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57
votes
16answers
7k views

Why is Morse Code still in use?

Why do people still use Morse Code? What are its advantages over newer Voice or Data communication modes?
44
votes
5answers
4k views

How do I report an emergency using ham radio?

If I'm in the wilderness with ham equipment but no phone signal, how would I report an emergency? Is there a particular frequency I would use, a particular protocol or suchlike?
33
votes
7answers
30k views

Using a balun with a resonant dipole

I am preparing to construct a resonant, center-fed, horizontal dipole. I have seen people use baluns at the feedpoint of the antenna, and some people swear by them, but I have never gotten a ...
33
votes
4answers
27k views

What's the difference between national calling frequency and national simplex calling frequency in the 2m and 70cm band plans published by ARRL?

On the 2 meter and 70 centimeter band plans published by the ARRL, what is the difference in intended use between the calling frequencies (144.200, 432.10 MHz) and the simplex calling frequencies (146....
32
votes
14answers
20k views

Can my neighbor's ham radio antenna be interfering with my internet signal or is my internet provider just throwing blame elsewhere?

My internet provider is telling me that an antenna on my neighbor's house, which he called a ham radio antenna, is interfering with my DSL internet signal. I'm not tech savvy at all, beyond what's ...
32
votes
2answers
43k views

Effect of different metals for antenna elements

Other than rust, corrosion, and other reactions with air that would make the use of a metal unfavorable, how do different metals affect the performance? Let's give Yagi an example: Let's say I use 4 ...
31
votes
11answers
3k views

Are there well-known methods that can help improve my CW copying speed?

I've been having a hard time getting my Morse Code copying speed above 7-10 words per minute. Are there any techniques I can use to improve my skill?
30
votes
6answers
35k views

Why do hams often conclude messages with “73”?

Looking at amateur radio forums and email threads, oftentimes amateur radio operators will use "73" or "73s" where one might otherwise expect to find "Sincerely" or "Regards". Why?
27
votes
6answers
27k views

Can I reduce RFI/noise at the antenna?

Recently, the power was out in my neighborhood for an extended period of time. I fired up my HF rig using battery power and was amazed at the lack of noise across the HF bands. When the power grid ...
26
votes
11answers
26k views

What's a cost-effective way to boost the range of my cheap 2m/70cm handheld?

I'm a very casual/beginner level ham and as such have mostly avoided committing too much in the way of financial resources - I have a UV-5R for a personal radio, anything else I do I've used others' ...
25
votes
4answers
3k views

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?
23
votes
4answers
8k views

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, ...
23
votes
1answer
5k views

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 ...
22
votes
2answers
55k views

Which HF bands are best during the day and which are better at night?

I am rather new to HF operation and have recently purchased my first HF rig. I have read about bands being "open" and "closed" based on various conditions including time of day. As I have been ...
21
votes
13answers
14k views

How can one convert from Lat/Long to Grid Square?

I see that many contests, awards, and other items, use Grid Squares as a means to identify where one is. How can one figure out what one's grid square is, given lat/long?
21
votes
7answers
2k views

Encrypted traffic and amateur radio

Am I allowed to send encrypted traffic via any medium or any frequency, or is this completely barred (and thus everything has to be open with no exceptions?)
21
votes
2answers
3k views

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 ...
20
votes
2answers
3k views

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 ...
20
votes
2answers
400 views

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 ...
20
votes
2answers
3k views

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 to handheld rigs transmit and recieve with just one wire ...
20
votes
3answers
24k views

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 ...
19
votes
8answers
29k views

How can I avoid accidentally transmitting with a Baofeng UV-5R?

I don't have $500 for a radio scanner. If I know the few (analog) frequencies that I would like to listen to, I think one can use the Baofeng UV5R (which doesn't cost much). The only problem is that ...
19
votes
10answers
82k views

What antenna on a BaoFeng UV-5R Pro will give me better reception? [closed]

I am happy with my BaoFeng UV-5R Pro but the local UHV VHF repeater and simplex reception is terrible, even for contacts less than 50 kilometers. I assume that it's because the rubber-ducky antenna on ...
19
votes
5answers
4k views

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'...
19
votes
3answers
3k views

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. ...
19
votes
5answers
7k views

SDR: Quadrature demodulation vs direct RF sampling

I see that many SDRs use a quadrature demodulator and sample I and Q signals. But is it possible to downconvert the RF signal instead, sample it with only one ADC, and get the same capabilities of ...
19
votes
1answer
283 views

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 ...
19
votes
1answer
4k views

Is “just listening” on EchoLink considered bad etiquette?

I was reading about EchoLink and came across this rule under "Access Policies": 2. No "SWL" (listen-only) access is permitted. EchoLink is a two-way system by design, and there is no mechanism ...
18
votes
5answers
6k views

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 ...
18
votes
3answers
649 views

What makes cellphone transmissions so energy cheap?

The modern cellphone can carry on a full duplex conversation for a time period measured in hours on a battery half the size of my handheld transceiver. My transceiver can barely receive for that ...
18
votes
2answers
9k views

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 ...
18
votes
3answers
7k views

Why do I need to tune an antenna?

I've heard that when an antenna is set up, it needs to be tuned to reduce reflective power back into the radio. Is this always necessary, and if so how would I go about tuning it?
18
votes
1answer
3k views

How does moving a feedpoint off-center in a dipole affect the resonant frequency and resistive load?

Specifically, I understand that OCF dipoles change the SWR, but does it do this via reactance or resistance, or both?
17
votes
3answers
3k views

SDR sampling bandwidth - do the bits per sample matter?

I'm looking at data converter chips for a homebrew SDR design, and I see that I can choose not just the sampling frequency, but also the bits per sample. Obviously the sampling frequency has to be ...
17
votes
3answers
2k views

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 ...
17
votes
2answers
2k views

Why do repeaters use cavity filters?

Repeaters apparently often use large, expensive cavity filters to connect the receiver and transmitter to the same antenna. Why aren't typical electrical circuits, such as inductors and capacitors ...
17
votes
8answers
24k views

Should I chose a vertical or a horizontal HF antenna?

If I only have the budget for one HF antenna, should I chose a vertical or a horizontal antenna?
17
votes
1answer
2k views

How does an SWR meter really work?

For ham radio operators, the SWR meter is a ubiquitous piece of equipment. There are dozens of standalone models on the market and most modern transceivers and antenna tuners have this functionality ...
17
votes
6answers
19k views

Using a Morse code key with a computer?

Are there standard ways to connect a hand key (straight or paddle) to a contemporary computing device (PC laptop with no parallel port, Mac, Android, iOS device, etc.) for developing or improving ones ...
17
votes
3answers
2k views

What is a “random wire antenna”?

Some antenna tuners claim to match any “random wire” to any HF frequency. Can one really use a random wire as a practical antenna system? From everything I have heard, the resonance of the antenna (...
17
votes
3answers
6k views

Understanding coax impedance

I keep doing research, and trying to grasp it, but when it comes to RF impedances, and coax, I still have trouble trying to grasp it. So first, I think you have to have a 50 ohm coax for a 50 ohm ...
16
votes
5answers
3k views

Can a licensed ham use or modify CB equipment to work the 10 Meter Amateur bands?

Can a licensed ham use or modify CB equipment to work the 10 Meter Amateur bands? If so, are there any advantages/disadvantages to this?
16
votes
4answers
17k views

What bands and modes will give me voice at 3,000 miles?

I pursued Amateur Radio primarily for local emergency communications and as part of my electronics education. My only radio right now is an inexpensive 2m/70cm HT which is good for local weather ...
16
votes
3answers
6k views

What's wrong with 220MHz?

It seems like 220MHz is the bastard step-child of the amateur world. Every HT is either 2m or 2m/70cm. Some companies offer tri-banders, but they almost always add 6m (?!), not 220MHz. The only way ...
16
votes
3answers
4k views

Why do we not use AM and FM at the same time to transmit more information?

Amplitude modulation uses the modulation of the amplitude of a carrier wave to transmit data while leaving the carrier frequency constant, and in the case of FM it's just the other way round. Why is ...
16
votes
1answer
18k views

How does a mag mount antenna achieve a ground plane?

I've been thinking for some time about magnet mount mobile antennas and wondering how they establish their ground plane. Consider that many mag mount antennas have some kind of protective coating on ...
16
votes
8answers
14k views

Are there any real advantages to an aftermarket NA-701 over the Baofeng stock antenna? [closed]

I have a Baofeng UV-5R HT radio that I have been using for about a month now and I really like it because it was very inexpensive and portable. It currently has the stock antenna on it and I have ...
16
votes
1answer
320 views

How do emergency nets work?

In movies that depict amateur radio in emergencies, the hams' worldwide communication network invariably is able to pass messages between individuals. As an amateur that has been primarily interested ...
16
votes
2answers
1k views

Is there a disadvantage to using a cheap HT for APRS?

Looking to build a cheap (not even inexpensive, just dirt cheap) APRS beacon transmitter. Right now you can get a dual band handheld transceiver with rechargeable battery, antenna, etc for under $31 [...
16
votes
2answers
3k views

Ham radio above 275 GHz

I see on the allocation chart all modes and frequencies are allowed above 275 gigahertz. Has anybody experimented with this? Are there interesting things you can do on these extremely high frequencies?...

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