Amateur Radio Stack Exchange
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1500 questions
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Cellular VHF Interference

I just got my license a week ago. Installed a new VHF/UHF radio in my car and everything seems to be working great. I've been heard at distant locations and picked up signals from repeaters that are way beyond where I expected to reach. However…
Matt KG7UDH
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Calculating effective SSN (sunspot number)?

I am doing research on how SSN-like parameters affect HF radio signals. As I can see, effective SSN is a parameter that is derived from SSN or using other parameters. Does anyone know how to calculate effective SSN? For example, this file has some…
lsc
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Morse code for hash (#)

Is there a morse code for a hash character? If so, what is that morse code? My thoughts where that there is morse code for an @ but why not for a #?
Thealon
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What does radiation power mean?

I would like to ask you what it means when it is written that a transmitter has 10 dBm power. Does that mean that 10 dBm is provided to the antenna, or that 10 dBm is measured at particular frequency at the receiving side?
Nexy_sm
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Stub impedance matching

What is the process of stub impedance matching and what are the elements included in the calculations relevant to it?
Max
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4
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2 answers

Coaxial Folded Dipole Antenna Matching Impedance

In http://www.nsw.wicen.org.au/technical/projects/coaxial-folded-dipole-antenna, the guy is using a 50 ohm coax cable to build a folded dipole antenna and claims that this will enable use at 50 ohm (I assume the required matching impedance). Now,…
user4575
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1 answer

Command-line satellite tracking software

Is there any software similar to Gpredict but which can be used without a GUI and can control rotor Az/EL and radio doppler shift? I'm using Linux in particular, especially Ubuntu 14.04. Currently, I can control rotors and radio via Gpredict's…
user80551
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What does multi-path sound like on FM?

I know I have probably experienced multi-path propagation on FM modes when I was working a repeater in the grand canyon and in the mountains. How can I identify when I am getting multi-path, and what does it sound like while using frequency…
Skyler 440
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What determines the optimum frequency range for the transmission of signals?

What determines the optimum frequency range for the transmission of signals in a system that's transmitting electromagnetic signals between an antenna on the surface of the earth and an orbiting satellite antenna.
Max
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4
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Are there any satellites with 435 MHz uplink?

I have a transceiver working in the 435 MHz ham band. I want to test my uplink capability by communicating with satellites operating in this band. Are there any digital satellites which I can use for this purpose?
Ashish kulkarni
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How should I mount a mobile antenna on a vehicle with a non-conductive body?

I would like to mount a self tuning antenna, ATAS-120, matched with the FT-857D transceiver. I would like to make this pair function on an ARGO 8x8 amphibious vehicle with a polyethylene body. There is a metal frame the engine and drive-train is…
scott
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Where does one find high-voltage variable capacitors and inductors for RF?

I'm looking to start building various antenna tuning circuits, but I'm limited by my parts inventory. I have pots and mag wire for winding inductors and a nice spectrum of fixed-value capacitors, but I have no high-voltage parts, nor variable…
wolak
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4
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2 answers

Can IMAP email be used for packet radio?

I just barely learned that IMAP is a protocol that allows you to read and respond to emails without using the internet. Would it be possible to use this application for packet radio and if so, how? I am using the Ubuntu 14.10 operating system.
BJsgoodlife
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Color of radio noise?

Is typical background RF plus radio receiver electronics noise (wide-band audio) closer to white noise or pink (1/f) noise? Does it depend on the demodulation scheme (AM/FS/SSB/etc.), if any, currently configured or the band being tuned?
hotpaw2
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Conversion from Baud to Bits per Second and then to Bytes per Second

How would I go about converting from Baud to Bits per Second (bps) and then from Bits per Second to Bytes per Second (Bps)?
W8AWT
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