Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

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1500 questions
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votes
2 answers

Dipole versus ungrounded end fed for HF RX

I've built a 2 meter ground plane antenna that works pretty well for RX and has a decent SWR on 2 meters with my Alinco. However, I'm experimenting with SDR quite a bit and would really like to build something for weak signals, especially CW and…
David Hoelzer
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Decoding weak APRS signals

I've recently started looking into APRS, and can easily receive some APRS signals from my station - however, I can't seem to decode them using QTMM or any similar software. Is this because they're too weak / noisy, or am I doing something else…
berry120
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4 answers

Requirements for 9600 baud

I want to setup a TCP/IP link between my friends house 7km away from me on 70cm. 1200 Baud is a bit slow, and we are looking into something with a faster data rate. I know normal audio does not work for 9600 baud packet. What are the…
Skyler 440
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New to Amateur Radio

I'm new to radio, and I'm trying to get into the electronics aspect of it. I was wondering if it was at all possible to build your own transmitter, receiver, etc. (basic radio components) as good beginner project. I've searched the Internet for…
rmutalik
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5 answers

Why needs a carrier signal on receiver (SSB)

why does the receiver needs to add a carrier signal to the SSB signal? I am new to ham radio and can't so much.
Axel
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5
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2 answers

Will measuring SWR through a feed line mislead me?

I know that except in the perfectly matched case, transmission lines transform impedances along their length; if I measure the impedance at the other end of my feed line, or even with a short jumper between my antenna analyzer and the antenna, I…
Kevin Reid AG6YO
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5
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Theoretical Wifi antenna not working for the expected range

You buy a "20dBi omni" Wifi antenna, operating in the 2.4-2.5GHz band. You note that the expected range is not achieved from this 300mm long antenna. What could be wrong? Can someone please tell me whether may approach is correct λ(min) = 300/2500 =…
HappyFeet
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1 answer

OK for S/RF light to be illuminated at engine idle?

I just installed a mobile CB (Uniden) into my Jeep. When the key is in auxiliary (car off, accessories on) and the squelch turned all the way down, no S/RF lights are illuminated and the background noise is relatively low. When I start the car, I…
jonathanbell
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1 answer

How does power received by a dipole relate to electric field intensity?

Let's say there's a transmitter far away, and I'm going to receive the transmitted signal. To keep things simple let's further say the transmitted signal is a pure, unmodulated sine wave. Further, let's say the electric field generated by that…
Phil Frost - W8II
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Where is the Multi-Drop XKISS / BPQKISS spec?

In packet radio, AX.25 is a fairly common layer-2 protocol. Many TNCs implement AX.25 in firmware, so the operator interfaces to the TNC with a serial port, using the TNC's firmware from a shell-like interface. Many TNCs also allow a "raw mode"…
Jacob
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1 answer

How to calculate power loss between radio and antenna

I have a 5W HT that only kicks out about 1W by the time it hits my antenna (which I understand is the norm). How do I go about calculating power loss in various equipment?
Dan
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Receive Data on Specific Frequency

So if I were to build a simple AM radio transmitter just using say, my Arduino, an oscillator, and wire for an antenna (this is all crude I know, but work with me here) and use it to transmit data collected or what have you, how do I receive and…
user2278224
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2 answers

How to choose right inductors for a matching circuit

I would like to chose an inductor to make a matching circuit. Operating frequency is 6.1 GHz. I am more concerned with self resonance frequency and Q of an inductor. Would an inductor with SRF > 7 GHz and Q > 10 be okay at above frequency?
Shiva Mudide
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2 answers

What is the impedance of a 1.25 λ dipole antenna?

I would like to make a dipole antenna. This particular antenna is used for reception only; no transmission is involved. I would like to receive as much power as possible by this antenna as it is used in energy harvesting. I read that a length of…
Shiva Mudide
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BAOFENG UV-5R for cubesat communication on lab, does it work?

Here we have a cubesat which operates in VHF/UHF. Communication with it (from a ground station perspective) is done with an Icom Radio. Would it be possible to replace it with a cheaper BAOFENG?
oqrxke
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