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1500 questions
6
votes
2 answers
Is copper-clad steel a good material for wire antennas?
There are some people selling steel wire plated with copper for making wire antennas.
Perhaps the most well-known brand of this product, Copperweld, makes at least two kinds of copper-clad wire, copper-clad steel (CCS), and copper-clad aluminum…
Phil Frost - W8II
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6
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1 answer
Noise bridge use in antenna construction?
How does a noise bridge work? And how can a noise bridge be useful in building, testing, and/or tuning an antenna?
hotpaw2
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6
votes
2 answers
Low parts count CW HF receiver?
I'd like to be able to provide my kids with the opportunity to build something a little better than a passive crystal set, but still very, very simple in terms of individual electronic parts count.
It seems to me that a CW receiver should be the…
Adam Davis
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6
votes
5 answers
Are QRP transceivers only meant for CW communication?
I was just thinking about making a QRP transceiver, but are they only used for CW (Morse code) communication?
If it is so, can I modify a QRP for two way audio communication?
Sumithran
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6
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1 answer
What is homebrew?
My question is the title itself: what is homebrew (or home brewing)? And how do homebrews differ from ordinary ham radios?
Sumithran
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6
votes
2 answers
Effective Area of Dipole Array
I'm trying to design a low frequency dipole interferometer antenna array. I am realizing how little I know about radio antennae. I'm confused by the concept of effective area $A_e$ and how it applies to arrays. I haven't been able to get a clear…
Spuds
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6
votes
3 answers
Call sign ID for a "homebrew" or improvised repeater?
I saw a couple YouTube videos last night about setting up a repeater using a pair of cheap hand-held radios and, at its simplest, an audio patch cable to connect the speaker output of one radio to the mic input on the other. Set frequencies…
Zeiss Ikon
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6
votes
1 answer
Is it safe to run two barefoot rigs on one antenna with an AB switch?
I have a Daiwa CS-201A two position switch. The single side is connected to by quarter wave vertical (40m). The A and B sides are connected to an IC-7300 and TS-830S.
The switch is claimed to have 60dB of isolation. It also shorts the unused port to…
Paul
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6
votes
2 answers
What are contests? What do I need to know about them being new to ham radio?
I have heard about radio "contests" but I haven't seen a real explanation of what they are and what they entail. What do I need to know about contests before getting a technician license for the first time? Is there any particular etiquette…
Rob Rose
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6
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1 answer
Why does adding 50-ohm BNC Ethernet terminator(s) in parallel to my 4-element yagi improve my radio's reception? (70cm)
I have this radio, with a rubber duck antenna, and a repeater twenty miles away to my north-northwest. If I set my radio on the top of a cabinet in my bathroom, I receive the repeater fine. I can't hit it from there, but I can hear it, which for…
CJ KE4EDD
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6
votes
1 answer
What should I look for in an antenna for a DVBT Dongle used for SDR?
I use a cheap DVBT dongle that I control via RTL-SDR. Right now a very basic setup. The general consensus seems to be that a long usb cable should be used (to keep noise from the computer away from the dongle) and the antenna directly plugged into…
mart
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6
votes
3 answers
Coax or bifilar windings for a choke?
Making a common mode choke out of bifilar windings has proven rather difficult. For me the difficulty lies in getting the impedance to remain a constant 50 ohms from on the HF bands. I've tried 14 gauge enameled and I've tried 18 gauge PTFE. The…
Paul
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6
votes
1 answer
Signing of messages transmitted over ham radio
FCC Regulation 97.113 (a) 4 states that:
"messages encoded for the purpose of obscuring their meaning"
Are "Prohibited transmissions", I believe this is the clause that is used to prohibit encryption over ham radios.
Are there any other clauses that…
DavidT
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6
votes
2 answers
What are some good options for covert dual band vehicle antennas?
Would like to have a 50W mobile in my SUV, but I'm not allowed to have a big whip on the outside.
What 2m/70cm dual band antennas are available that don't say, "Ham Radio Operator"?
Are there three band antennas that replace the radio antenna?
I'd…
Adam Davis
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6
votes
4 answers
How far do radio waves travel?
I have read that radio waves just keep traveling but the signal gets weaker because of how the wave spreads. OK, I get this, but what confuses me is that satellites emit signals from space that our phones and GPS modules pick up regardless of…
sirshakir
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