Amateur Radio Stack Exchange
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1500 questions
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3 answers

Why are Amateur Radio operators so obsessed about and hostile towards violation of the rules?

Please don't downvote just for the title, I'm not trolling, and honestly looking for an answer. I'm not directly involved with Amateur Radio, but have friends who are. They're always by the book. The book is right. period. With amateur radio, if you…
user1882
6
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1 answer

Can I still use my Kenwood TM-281A for normal communications even while I have a TinyTrak4 connected for APRS use?

I am considering buying a Byonics TinyTraK4 to connect to my Kenwood TM-281a to do APRS. However, I am wondering if I should instead buy a separate radio (I am considering a Baofeng UV-5R) as well and connect the TT4 to it instead of the TM-281A. My…
W8AWT
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Effect of night on VHF/UHF propagation

I have had some conflicting experiences relating to the effect of night time (ionosphere, temperature, etc.) on propagation. Perhaps it is related to the frequency of what I was working with. Several years ago I troubleshot a Wi-Fi network in the…
Ken - Enough about Monica
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What protocol or API does WebSDR use to stream audio?

What documented protocol or API does WebSDR use to stream audio over the internet? I'm interested in capturing a WebSDR audio stream using a small embedded device which has lots of audio DSP capability, good internet access (TCP/UDP network…
hotpaw2
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6
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Why do 9:1 ununs use type 2 material for the core?

I do not understand how a 9:1 unun wound on a T200-2 works. I understand the transformer voltage and current ratios. I have wound several toroid chokes and 49:1 ununs and know how they work. What is throwing me is that all designs I see use type 2…
Dereck
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Why not access the AO-91 satellite at night during eclipse?

According to amsat-uk.org, the AO 91 satellite should not be accessed during eclipse because it is near EOL. AO-91 (RadFxSat / Fox-1B) Near end of life. If you find it on, do not attempt to access in eclipse! (That is, don't use it at night) I'm…
KJ7LNW
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License problem in Spain

I am from the UK and live in the Canary Islands. I am told I have to take my ham radio license test in Spanish, but I don't speak Spanish. Is there a way around this somehow? Maybe take the UK one (online) or another one in an English speaking…
Stewart Astley
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3 answers

Does an End-Fed Antenna need to be straight?

Typical yard and wondering if I can go out a window, to a tree, turn to another tree, turn to another tree simply trying to achieve the length required for 80m band? One video stated it doesn't need to be straight, but need to verify.
Mot
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2 answers

Why don't J-Poles need to be grounded?

I'm building my first J-Pole and the different projects and articles I read about differ slightly but one commonility is a J-Pole does not need to be grounded. Why is that? I read that it is optional to ground the J-Pole antenna to deal against…
john_ham_radio
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3 answers

Is a boom important to a Yagi?

I am trying to make a yagi for a 900M. The tinkering starts causally with some 1.2mm welding wire (cut to size based on K7MEM yagi calculator, direct soldering, no special matching as suggested on K7MEM page) glued to a 1mm plastic strip, since I…
Ben
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6
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3 answers

2.4 GHz Antenna for RC copter

What is the best omni-directional antenna design for any RC flying objects? Many times I've lost signal and my copter falls due to lost signal. (Using default antenna). Since the receiver and transmitter position will be in different altitude, I can…
Bianca
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How to achieve highest Q-factor in inductors for 6-160m amateur bands?

When building filters for ham bands (direct sampling SDR frontend) - it is common to build filters using 2,6,10,12 material toroids. Are there any recent developments that offer lower losses / higher-Q in amateur bands? (6-160m) Are there any other…
BarsMonster - R2AYN
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6
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How is FT8 modulated with both upper side band and FSK?

This Wiki shows FT8 mode is USB and its modulation is FSK. I don't get the difference between mode and modulation, I thought they are the same thing? Aren't signals modulated in a single method, transmitted and then demodulation with a receiver with…
Dan
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All male BNC connectors have a rubber gasket: are they rain-proof by design?

This question is about the BNC connection interface itself and not how the coax is attached (assume the coax is attached in a rain-proof way). While inspecting a male BNC connector we noticed that there is a rubberized gasket in the back that the…
KJ7LNW
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How do I keep the bomb squad from winning a foxhunt?

I want to hold a fox-hunt in a relatively public location, such as a park or college campus. The fox that I've built uses an ammo can with a rubber duck antenna. It occurred to me that this combination makes for a somewhat suspicious package. My…
W5VO
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