Amateur Radio Stack Exchange
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1500 questions
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1 answer

What is the difference between MFSK64 and MFSK64L?

I noticed this after updating fldigi to decode a Voice of America Radiogram. The only thing I could find in the fldigi changelog was this: MFSK HF Long Modes * Added MFSK64L and MFSL128L new modes * 6.25 Second interleaver for very-robust HF…
Sterling N0SSC
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How to renew an expired US license as an expat?

I've been living as an expat for a decade, and my extra class license expired a little more than a year ago. I'm currently in Taiwan. Is it possible to renew my license while staying here? Can I do it completely electronically? Or do the exams still…
uhoh
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Emergency/battery power rules for Field Day: do they include computer equipment?

There are some contests such as ARRL's Field Day that provide special categories or points for contestants who operate using emergency or battery power. The 2016 FD rules for "Class A - Battery" stations include this text: All contacts must be…
Jack Twilley
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1 answer

How to make a PTT button for Baofeng UV-5R

I use the radio for paragliding and the radio is mounted on a "cockpit" in front of me when flying. When in flight my hands are busy. I can hear the radio fine (don't need an earpiece) and I can transmit fine too (others can hear me, don't need a…
Andre
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Can I use a Hawaiian call sign on the mainland?

A ham is initially licensed in Hawaii as KH6ABC (example only). If he subsequently moves to the mainland, can he keep his geographically restricted "KH" call sign or must it be changed?
Lance
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3 answers

What is a panadapter?

To what does the term "panadapter" refer? (Physical hardware or software?) How did the term "panadapter" originate as related to radios or electronics? How is the term "panadapter" different from the spectrum and/or spectrum waterfall display on…
hotpaw2
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Have hams ever used (clusters of) geostationary satellites as passive microwave reflectors?

A number of geostationary satellites are quite large and/or appear in clusters. Moreover, many of them have large reflectors pointing to Earth (e.g. satellite TV sats). Finally, these satellites are located at roughly $\frac{1}{10}$ the distance…
on4aa
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Single Side Band AM vs FM

I know the difference between AM and FM, but could anyone explain to me what is the differences between single side band AM and conventional FM? So far as I know the SSB modulation will reduce the transmitting power. But what is the exact function…
hellojoshhhy
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1 answer

What is a good way to bench test a mesh network?

I've been experimenting with some 2.4ghz based mesh networks similar to http://hsmm-mesh.org/. I'd like to have something on the bench where I could simulate roving between nodes, and create hidden nodes and varying signal strengths. Is there a…
K9KRB
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Wider wire = picks up more energy, yah?

I have seen many discussions re: wire gauge, insulation, velocity factor and K-factor...unfortunately, statements from various sources are not always in agreement, but that is not the issue. The issue that I have never heard discussed seems like a…
Mein Tenah
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cubesat turnstile antenna material selection

My cubesat team is working on our design for rolled whip antennas to deploy in a UHF turnstile configuration based on this design: What I would like advice on is the material for the antennas themselves. Spring steel has ideal mechanical…
Kontakt
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DMR / DSTAR / P25 Software Encode / Decode

The large VHF / UHF digital voice communication modes all require the same AMBE vocoder chip from dvsinc. This surface mount chip can be aquired standalone for a relatively high price or all of the required encode / decode electronics can be…
Skyler 440
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Antenna for a cramped attic

Brand new Ham. I bought a cheapo UV5 right before I got my call sign. I want to set up a decent 2m/70cm station for starters and I realize that a better radio is important but wanted to knock out the antenna situation first. I live in HOA hell so no…
ThaKidd KG5ORD
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How to choose the right sampling rate and bandwidth for RTL-SDR dongle?

Receiving the frequency of 97.9 MHz I have a Terratec SDR dongle and I am trying to capture a radio frequency. The FFT window shows the frequency range from -500 to 500 KHz. Is there a way to increase this or it depends on the dongle and is fixed?…
Jack
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Should I learn morse at "both" speeds?

There are many anecdotes of hams learning Morse Code at e.g. 5wpm and then "hitting a wall" trying to gradually speed up to 15wpm. David G. Finley, N1IRZ claims the reason is this: Morse at 5 wpm and Morse at 15 or 20 wpm are completely different…
natevw - AF7TB
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