Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

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1500 questions
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Mounting my antenna

I just bought a CB and mounted it in my truck. I ran my antenna to the back and was going to stick it to my tool box but it turns out to be aluminum, so I'm thinking of bolting a metal plate to the top so the magnet will stick. Should I attach a…
B Wingfield
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How big is a decibel?

Say I've calculated that my feedline losses are 3dB, or I'm considering an antenna with 10dB gain, or trying to decide between a transmitter with 10dBm output power versus 16dBm (6dB difference). I understand a decibel is a degree of change in…
Phil Frost - W8II
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Distance between antenna and radio

I live in a small cottage with an unlevelled terrain. My house was built in the lower part of it (left-side), and in the other half of it there is a hill. On top of the hill there's a fairly good plateau where I would like to have my antennas…
Former User of Mine
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Good FM receiver single-chip IC for simple VHF receiver?

Is there an IC out there that implements all, or most all, of a simple FM receiver in the VHF range? I'm interested in doing some experiments with using DTMF over the air for tele-commands and the like, and I'd like to keep the receiver electronics…
mindcrime
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Can I use old TV FM card as SDR?

I tried searching a lot before, but couldn't find anything about it; I have an old TV/FM card from an old computer, I wish to know if it can be used as an Software Defined Radio, and if yes, how? The one I have is the same as this…
Miguel Vieira
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Software defined radio demodulation

I am trying to increase my knowledge on software defined radio and according to what I have read its hardware consists of three parts: Amplifier Tuner ADC I just wanted to make sure that my assumption that the filtering and demodulation is done…
Jack
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If EM waves require no medium, why can't I get service at all times?

I have taken two years of high school physics and am very interested in RF communication. I know that electromagnetic waves do not necessitate a medium in order to propagate. Thus, shouldn't I be able to send/receive RF signals even when the signal…
MikeE
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Where year 2016 falls in the sun spot cycle for HF propagation?

Are we now at the good or bad portion of the 11 years cycle? What effect are we seeing now? How large (strong/deep) is the effect during the peak and bottom of cycle? What will change in coming years?
EEd
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BFSK with huge spacing, why?

I recently bought one of the classic USB dongles to experiment with SDR. At 460MHz (Europe, CH) I constantly see many digital transmission that use BFSK. What is strange to me is that: the frequency spacing is about 9KHz, instead of the much lower…
MarcoM
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How Are US Call Sign Location ID's Assigned?

If I take my license exam in California, but my residence is in New York, would my call sign still reflect the New York location?
user7822
5
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4 answers

Recommended way to analyze spectrum output of a high-power amplifier?

I have a small collection of "software defined RF lab" equipment, notably a HackRF and a VNWA3. I am almost done building a 35W HF amplifier and once I've done some other testing, would like to look at the spectrum of the final output as a…
natevw - AF7TB
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Use ham to broadcast GPS RTK correction data

I am involved in a precise positioning project that uses Real Time Kinematic (RTK) for cm-accurate positioning. We use unattended base stations that provide real-time corrections for mobile rovers. The corrections can be used within a radius of…
Kozuch
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How can I know whether a radio is FCC approved?

I'm considering buying a new HT radio (Hong Ying HX-860UV Handheld) from China. The company says the model is approved by the FCC. Since I can't see it in person (only a photograph), I can't confirm. How can I be sure they are telling the truth?
W D Patterson
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Squelch never seems to "open the gate" on Wouxun KG-UV9D

I just got my Technician's license a few weeks ago and I'm trying to figure out if this is user error or if I need to return my radio. My understanding of squelch is that when the received signal strength exceeds the squelch threshold the radio…
Matt KI7CMZ
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Amateur Radio for a Nomad

I got my amateur license back in the early '80s, primarily for putting it on my resume for an electronics job. Never used it outside of developing my Morse code speed, and once I got my Advanced Class and short call sign, I never used it again. Well…
KiloVoltaire
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