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64 votes
18 answers
9k 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?
Timtech's user avatar
  • 2,336
51 votes
5 answers
9k 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?
berry120's user avatar
  • 1,744
42 votes
7 answers
49k 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 ...
W5VO's user avatar
  • 1,901
40 votes
6 answers
71k 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?
Amber's user avatar
  • 2,728
37 votes
4 answers
45k 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....
Andrew N5ITM's user avatar
36 votes
14 answers
41k 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 ...
Vanessa's user avatar
  • 361
36 votes
4 answers
57k 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 ...
Skyler 440's user avatar
  • 7,620
34 votes
14 answers
5k 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?
dcaswell's user avatar
  • 803
33 votes
2 answers
103k 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 ...
ghendricks's user avatar
31 votes
6 answers
41k 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 ...
The Driver's user avatar
28 votes
13 answers
22k 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?
PearsonArtPhoto's user avatar
28 votes
11 answers
35k 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' ...
Amber's user avatar
  • 2,728
27 votes
9 answers
71k 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 ...
user4777's user avatar
  • 293
27 votes
4 answers
6k 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?
user's user avatar
  • 4,868
27 votes
4 answers
20k 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, ...
K9KRB's user avatar
  • 642
27 votes
7 answers
8k 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?)
berry120's user avatar
  • 1,744
27 votes
5 answers
13k 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 ...
Seth's user avatar
  • 734
26 votes
2 answers
6k 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 do handheld rigs transmit and receive with just one wire ...
Skyler 440's user avatar
  • 7,620
25 votes
6 answers
15k 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 ...
berry120's user avatar
  • 1,744
25 votes
1 answer
7k 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 ...
dcaswell's user avatar
  • 803
25 votes
3 answers
45k 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 ...
natevw - AF7TB's user avatar
24 votes
3 answers
721 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 ...
Kevin Reid AG6YO's user avatar
  • 24.7k
23 votes
4 answers
6k 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'...
flux's user avatar
  • 231
23 votes
2 answers
5k 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 ...
David VK2VXK's user avatar
23 votes
2 answers
19k 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 ...
Phil Frost - W8II's user avatar
23 votes
3 answers
4k 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. ...
SP5RFD's user avatar
  • 333
23 votes
2 answers
7k 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 ...
BenSwayne's user avatar
  • 691
22 votes
4 answers
3k 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 ...
Phil Frost - W8II's user avatar
22 votes
1 answer
896 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 ...
user's user avatar
  • 4,868
21 votes
4 answers
25k views

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: ...
AndrejaKo's user avatar
  • 2,893
21 votes
5 answers
78k views

Good wire for wire antenna?

What properties should I look for in a good wire for building a wire antenna? Could anyone recommend something specific for me?
Timtech's user avatar
  • 2,336
21 votes
1 answer
5k views

Why do people say, "get a nickel," on repeaters?

Sometimes, I'll hear someone say "wait a moment, I'm getting a nickel," and then drop the carrier only to resume talking. Why?
webmarc's user avatar
  • 4,289
21 votes
3 answers
9k 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?
berry120's user avatar
  • 1,744
20 votes
10 answers
100k 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 ...
Warren  VE3WPX's user avatar
20 votes
4 answers
16k views

What is the peak voltage at the tips of a dipole antenna?

What is the peak voltage present at the very end tips of half-wave dipole antenna in free space, and how might this peak voltage relate to transmitter type, transmitter power, RF frequency vs. antenna ...
hotpaw2's user avatar
  • 13.5k
20 votes
6 answers
10k 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 ...
BarsMonster - R2AYN's user avatar
20 votes
2 answers
15k views

How to detect common-mode currents or “RF in the shack”?

Let's say we already know that if your antenna is not suitably constructed or connected then you can get current on the shield of your coaxial feed line which will flow through the shielding/grounding ...
Kevin Reid AG6YO's user avatar
  • 24.7k
19 votes
5 answers
9k views

FCC sends "Notice of Dismissal" with quite threatening language just for denial of a vanity callsign?

I had applied for a vanity callsign which wasn't available. That was in March. The FCC license system shows my old callsign is still in effect. Today, after a longer absence from my mail, I open a &...
Gunther Schadow's user avatar
19 votes
5 answers
16k views

Why do folded dipoles have greater bandwidth than ordinary resonant dipoles?

This is something I've read in passing, but never encountered an explanation of why. For example, Wikipedia says: Another common place one can see dipoles is as antennas for the FM band; these are ...
Phil Frost - W8II's user avatar
19 votes
5 answers
41k views

What do "QRM" and "QSB" refer to?

An answer on Basic QSO format? mentions things like "QRM" and "QSB". What do those terms mean?
Amber's user avatar
  • 2,728
19 votes
3 answers
7k 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 ...
Adam Davis's user avatar
  • 12.2k
19 votes
3 answers
805 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 ...
Adam Davis's user avatar
  • 12.2k
19 votes
3 answers
35k 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 ...
Peter KB1AVL's user avatar
19 votes
3 answers
4k views

Why do amateur radio operators call an RF choke a balun?

When using a balanced antenna such as a half wave dipole, with an unbalanced feed line such as coax, an RF choke can be used to block RF current emitted by the transmitter from splitting up at the ...
Andrew's user avatar
  • 3,693
19 votes
2 answers
32k views

How do I make a RF propagation map for a repeater?

Let's say I have a repeater. Knowing all of the information about antenna height and gain in each direction, as well as power, how can I create a map similar to this map I saw of a repeater in ...
Skyler 440's user avatar
  • 7,620
19 votes
6 answers
35k 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 ...
hotpaw2's user avatar
  • 13.5k
19 votes
6 answers
5k views

What defines music, per amateur radio regulations?

Sometimes when I access IRLP nodes, they have a very short melody telling you that you are connected; or when my local repeater's net begins, it does the famous doorbell 8-note sequence. What is the ...
Skyler 440's user avatar
  • 7,620
19 votes
1 answer
5k 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?
Bill - K5WL's user avatar
  • 1,194
18 votes
6 answers
25k views

What's the difference between saying “CQ” or “QRZ” in a contest?

I'm listening to (or let's say I'm trying to participate in) a contest (or perhaps Field Day), using SSB. I noticed that a station would, after completing a contact, sometimes say “CQ” and sometimes ...
Kevin Reid AG6YO's user avatar
  • 24.7k
18 votes
1 answer
6k 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 ...
Glenn W9IQ's user avatar
  • 18.6k

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