Amateur Radio Stack Exchange
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1500 questions
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Getting Started In Ham Radio

I'm 13 years old. I hear all the fuss about ham radio how awesome it is. I really want to join, but I hear you have to get a certification. How much does it cost? How long does it take? How much does a ham radio cost? What could you do with it?
hopefulhacker-Reinstate Monica
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World wide Radio Module

currently I am involved in a project were a data link is needed to communicate different devices. This is in one to many configuration and the devices are stand alone. For this project there is need 9.2Kbps, even less, and the expected coverage is…
Jordi NC
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Designing a helical antenna for a dish

I'm interested in a dish antenna with an axial mode helical feed for receiving video. My target frequency is about 1280 MHz or the 1.2/1.3GHz range. I've been able to figure out helical basics, like circumference equals wavelength, more turns is…
Gabe
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Problem with theory of HF detector

I'm currently trying to build my own SWR power Meter. This design is based on the so known HT detector with schottky diode BAS70. For my understanding, and for easy purpose, I'm currently focusing on 50 MHz. First, I found a nice theory called "The…
F4BJH
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What is IQ in the context of SDRs?

What is IQ, in the context of software-defined radios (SDRs)?
Geremia
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Is "coil loading" a type of impedance match?

If I have a too short dipole, or vertical, I can add a coil to lenghten in electrically. But it's my understanding that I could also do this with any other kind of match: given the complex impedance at the frequency of interest, I could calculate,…
hjf
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How long does it take the FCC to process vanity requests?

How long does it take for the FCC to process vanity callsign applications? My application shows as Pending in license manager but oddly does not show up at all in Application Search.
user16809
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Must all three VEs hold the required licence class to "prepare" an examination, or just one?

47 CFR § 97.507 states that: (a) Each telegraphy message and each written question set administered to an examinee must be prepared by a VE holding an Amateur Extra Class operator license. A telegraphy message or written question set may also be…
krzysz00 KF5SOQ
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Using an SDR on a Laptop with Noisy Power Supply

I'm going to start this off by saying I'm very new to this and I don't really know a lot so any detailed information would be much appreciated. I have just started using an SDR (a cheap RTL model) with my MacBook Pro laptop. The laptop itself is a…
TitanShadow
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Looking for a book that contained a circuit for receiving (literally) underground amateur radio transmissions

In this comment in Earth Science SE I've said: This is a really cool question! I remember (a long time ago) reading about electromagnetic waves inside conductive soil that travelled near but below the Earth's surface for at least a few miles, and…
uhoh
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Demodulation based on external frequency source

I saw a design for a walkie talkie that used a mixer that mixed the TX freq to the RX path before demod. Looking at the SA616 chip, demod is acomplished by Gilbert cell quadrature detector that is downstream from this. The simplest FM detector is…
Ben Madison KO4UXC
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4:1 Balun question

With an OCF dipole, does it matter which leg, short or long, is connected to which side of the 4:1 balun, hot(coax center) or shield? How can you tell which is which, the balun is not marked. Thank you.
John
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What is a QSL card?

What is a QSL card? Why would I ever receive one? Why would I ever bother to send one? If so, when? Is it rude not to? Are they postcards sent by physical postal mail, or are they now digital thingys?
hotpaw2
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What gain and power are required for successful DX contacts on 2m/70cm bands in CW?

I would like to practice in CW on 2m/70cm bands when and if there will be a tropospheric or sporadic-E propagation. However I don't have mush space for the antenna. There is a possibility to install 3+5 el Uda-Yagi antenna on the balcony (the height…
Aleksander Alekseev - R2AUK
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Do External Signals Affect Antenna S11/SWR Measurement?

Do external signals affect the S11/SWR measurement of an antenna? For example, if I try measuring the S11/SWR of an HF antenna with a SWR meter or a Vector Network Analyzer in the middle of a field day with many transmitters near the antenna, or try…
比尔盖子
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