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1500 questions
4
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1 answer
Is ladder line necessary when using a non-resonant dipole through a tuner?
I've heard if I have a dipole of some arbitrary length, or a random wire, the SWR can be very bad. An antenna tuner can present a decent match to the transmitter, but the SWR on the feedline will be very high, and thus ladder line is required.
Is…
Phil Frost - W8II
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4
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3 answers
What kind of antenna connector is this?
I'm looking for antennas to attach to my CB radio. This one is a "rubber ducky" antenna.
I'm not sure what the connector is, can anyone identify it for me?
[edit] Here are some other pictures
ToastHouse
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4
votes
2 answers
Choosing a wideband antenna design
On a previous question I asked about proper antenna design for wideband SDR receiver and ways to improve signal/noise ratio. Ideally the reciever has a range of 100kHz-2GHz. Keeping in mind is impossible to cover the whole spectrum with one antenna,…
Luca
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4
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3 answers
Antenna tuner design
In a related question about a broadband antenna for SDR it was suggested me to build or buy an antenna tuner.
Since maybe it was not clear to everybody, I'm designing an antenna tuner for reception, not transmission.
Searching around I concluded…
Luca
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4
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3 answers
Broadband antenna for SDR radio
I recently bought a very wideband SDR receiver (DX-Patrol MK4, declared covered frequencies are 100kHz-2GHz). I'm experimenting with antenna designs because unfortunately I live in an apartment building in the middle of the city and is not exactly…
Luca
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4
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1 answer
Is the error rate for QPSK31 in a white noise channel worse than BPSK31?
I've read in a couple sources that in a channel consisting of only additive white Gaussian noise (AWGN), at low SNR, QPSK31 is actually worse than BPSK31.
http://www.arrl.org/psk31-spec, probably copied verbatim from…
Phil Frost - W8II
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4
votes
1 answer
Could UHF Earth-Satellite-Earth bouncing of signals off of this large metallized foil satellite be feasible?
The July 14, 2017 NASA Spaceflight article Soyuz 2-1A launches with Kanopus-V-IK and over 70 satellites says:
Mayak is a three-unit CubeSat which was built by Tvoii Sektor Kosmosa – or “Your Sector of Space” – an independent, crowd-funded team of…
uhoh
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1 answer
What would letter T mean in this radio beacon message?
I'm currently picking up signal from a beacon using RTL-SDR and decoding the Morse code on a computer using gMFSK program.
The beacon is sending message which decodes as "T DE YU1VHF LOC KN04OO".
I still haven't started learning how to decode the…
AndrejaKo
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4
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3 answers
Colocated three orthogonal wire loops for lightning detection network
I'm considering building multi-turn wire loop receive antennas for a blitzortung.org lightning detection receiver. It has three separate channels for H-field antennas, operating simultaneously.
Typically, only two orthogonal loops in vertical…
Xpector
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4
votes
5 answers
What's this maybe-morse-code "CQ CQ GE EDEN" and "DD" in Le Eden de la Grisaia?
The ending song of an anime television series called Le Eden de la Grisaia here has a light flashing. I suspect it may be Morse Code. By watching the video a little more slowly than usual (frame by frame), it's easy to see that
dit is 2 frames
dah…
pj-yn9aq
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4
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3 answers
Satelite dish modified for Wi-Fi (Signal Elevation Question)
I am doing a project where I will be re-purposing an old TV satellite dish as a directional Wi-Fi antenna. The dish is circular in shape, not oval. The dish has an arm coming from the bottom that makes a 90 degree angle with the dish. I will be…
Jake Psimos
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4
votes
1 answer
What are the consequences of poor station grounding?
What can happen if I don't properly ground my equipment?
JC Hulce
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4
votes
2 answers
SDRPlay RSP1 and broadcast band (AM) interference
I heard the SDRPlay RSP2 has an AM notch filter, but I don't want to spend that much money. How is the RSP1 for broadcast band interference? Will I need a preselector? I already have an MFJ-1020c but am hoping to sell it to offset some of the cost…
K8KV
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4
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3 answers
Suggestions for HF antenna for occasional use on my sailboat
I have had a license since I was a kid, but have not touched anything ham radio related in years. I have been thinking about diving back in and combining it with my sailing. I'm looking for thoughts on an HF antenna that I can easily deploy when…
Jim Archer
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4
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1 answer
Pirate Radio vs Ham Radio
I've recently came across the terms "Pirate Radio" and in the URL of this page, "Ham Radio". What is the difference between these terms? And what is the difference between the transmission of a Pirate Radio and a Ham Radio.
anonymous
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