Amateur Radio Stack Exchange
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1500 questions
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Is there any downside to getting a vanity callsign?

I just got my HAM license, and I have been thinking about getting a 1×3 vanity that I can remember more easily. This question is partially in reference to this passage on the FCC site: A club station trustee of a club that has been assigned a…
Stephen Smith
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Troposcatter: really all that bad?

The previous question, Packet Radio at 100 miles and specifically, Phil's answer raised an interesting question: In a 50–100 km distance situation where Line-Of-Sight beams aren't an option for communicating data, can we, given the technological…
Marcus Müller
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How to determine antenna height for given HF frequency and coverage radius?

I'm planning on setting up a low-HF antenna for near to mid-range contacts. In my particular case, ideally I would like to be able to cover a radius of approximately 1000-1200 km with good reliability, operating on 3.5 MHz and possibly supplanted by…
user
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Cause of harmonic spurs?

Harmonic spurs (harmonics of the transmitter frequency, as seen by a wide-band receiver or SDR) in the RF spectrum might be caused by an imperfectly sinusoidal or badly filtered transmitter carrier frequency oscillator, non-linearities in the…
hotpaw2
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What kind of antenna is this?

This was found among some old ham stuff and is believed to have been used on 2 meters. The vertical elements are 17 1/2" long and the connector on the bottom is a standard SO-239. Antenna (left) and Connector (right) (See test results below…
Lance
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Where can I find a listening guide for different frequencies and their usages to listen to on SDR?

I just got an RTL-SDR dongle by Nooelec and am using CubicSDR on Mac (which supports AM, FM, and SSB), and I'm in Canada. I'm able to easily find FM radio stations, but outside of that I'm not sure where to look for interesting frequencies to listen…
user9315
6
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1 answer

1280 MHz propagation out of a mountain valley

I live in a small valley, surrounded on three sides by 200-300 foot ridges. I'm trying to figure out where to place an antenna mast to receive 1280 MHz video from a long range aerial vehicle (20-30 mile radius). At this frequency, how important will…
Chris
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Are some ferrites porous enough they should be protected outside?

I recently bought a couple of 61-mix toroids, and as usual I wrote the mix number on them before they become mystery parts. However, the ink soaked right into the ferrite. I've left ferrites hanging out in the weather, getting wet and frozen without…
Phil Frost - W8II
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Which countries require you to change your call sign if you change your residence?

I live in Austria (OE). There we have to change our call sign if we move beyond one of the 9 Austrian federal state's border. For example I lived near Innsbruck (Tyrol) with the sign OE7TKT. I moved to Graz (Styria) for studying - new call sign…
Tom Kuschel
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SSB offset determination?

Is there any algorithmic way to determine if the mixed frequency offset in an SSB SDR demodulator is wrong (too high or low), other than listening for funny sounding voices? (perhaps by checking to see if voiced vowel spectral overtones fall in a…
hotpaw2
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Is a ground plane necessary for transmitting and receiving with a vertical (monopole) antenna?

I've read the post here: https://electronics.stackexchange.com/questions/77256/why-do-some-radio-antennas-require-a-path-to-ground-and-some-do-not which says The antenna system requires a "ground plane" for the radio wave to form. With dipoles, one…
Steve
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What is a shallow/deep QSB?

Probably all amateurs recognize QSB as the q-code to represent 'fading'. I recently encountered the terms Shallow QSB Deep QSB A quick google search failed to yield fruit; What do the above terms mean?
VU2NHW
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How to calculate single-stub match (general case)?

I'm trying to build a 1/2 wave "Coaxial J-Pole" antenna, similar to what is described here: Such an antenna would be great for stringing up in a tree when operating remotely, no tuner needed. The trick is that I'm trying to use 75Ω RG6 coax for the…
Robert Quattlebaum
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Does the wire/conductor size of all the elements affect antenna bandwidth?

Does the wire diameter of the reflector and the directors of a beam antenna affect the bandwidth or is it only the driven element diameter that has this effect?
Mein Tenah
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Are there easier ways to make traps than coax and plastic pipe?

I recently built an antenna for my attic inspired by http://degood.org/coaxtrap/. I found making the coax traps very time consuming and frustrating to tune. I got to thinking about 3D printers, and I've been wondering if there is a better option…
K9KRB
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