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1500 questions
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Can you use a satellite dish for a ham radio antenna?
Can I use a satellite dish as a ham radio antenna? I was thinking that because there are two unused, working satellite dishes that have all appropriate wires attached conveniently to the roof of my house. Would there be a way to use the dish as a…
hopefulhacker-Reinstate Monica
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Is "low loss" cable required for HF?
I use RG-58 for all my HF antennas, since it's light, flexible, convenient, and cheap. And super easy to choke. Whenever I have a problem I just loop a few turns of it on a ferrite core and the problem goes away. Since I operate 100W max and all my…
hjf
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Practical limits to maintaining coherence in an HF channel
Lately I've been thinking about weak signal communication on HF. Very weak, like weaker than even WSPR could achieve.
It would be nice if one could simply take any existing modulation and slow it down to achieve an arbitrarily high Eb/N0 and thus,…
Phil Frost - W8II
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11
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Will electrically joined dipoles of different lengths, at right angles, behave as a multiband antenna?
I haven't seen this done, (which, after more than a century of amateur and professional radio development, is probably a bad sign), but I had an idea the other day for simplifying the setup and feed to cover more than one band without the compexity…
Zeiss Ikon
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11
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4 answers
What is dBm and why is it used rather than watts?
Reading through an RF power amplifier datasheet, I found the sheet only referenced dBm output power, rather than watts.
What is dBm?
How do I convert it to watts?
Why, or when, would you use dBm to specify power output rather than watts?
Are there…
Adam Davis
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11
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Why would you need a signal generator to receive early satellite transmissions?
I recently watched, on You Tube, a NOVA program about the British school masters and students who were the first to publish the news that the Soviets had started launching satellites from a new launch site back in 1958. (School Boys Who Cracked the…
John Warren
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What is the advantage of making an antenna resonant?
I am constructing a small loop antenna; apprx 4' diameter, will be used with an antenna tuner (mounted at the feedpoint) and 100W transmitter, and hope to use it on 20m, 40m, and maybe other bands if possible. I can add a tuning capacitor to make…
Chris K8NVH
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How can I participate on Echolink with my Android phone?
I want to use my Android mobile phone to send and receive over Echolink, like if I was using an amateur radio station. How can I do that?
I'm a SWL and only plan to listen until I get my license, and my brother does have a valid amateur radio…
ReNiSh AR
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11
votes
3 answers
How can I get rid of RFI coming from my house solar panel inverter?
The solar system on my house creates horrible rfi on all hf bands during the day when the sun is out, it goes away when it's not sunny. Any one got any ideas how to get rid of the rfi ? I already tried putting capacitors across the high voltage…
Andrew
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11
votes
2 answers
Why do some DX listen on a different frequency than they transmit on?
I've heard some DX indicate "CQ up 5" for instance, indicating that they are listening on a different frequency than they are transmitting on.
What are the reasons one might want to do that?
Adam Davis
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11
votes
4 answers
How do I increase my phone intelligibility?
Listening to various operators at different times, I've sometimes noticed, especially during contests, that some operators are easier to understand than others, and it doesn't all seem to be due to their speech patterns. The audio doesn't sound good…
Adam Davis
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11
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3 answers
What skills will I learn from contesting?
I got into Amateur Radio for emergency preparation and to allow me to expand my electronics hobby. My needs are being met, but I'm wondering if I'm missing out on increasing my skills by avoiding contesting which, in and of itself, doesn't…
Adam Davis
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10
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1 answer
Does Coax Limit the Maximum SWR a Transmitter 'Sees'?
A recent discussion about SWR led to the assertion that a length of coax cable will ultimately limit the SWR to which the transmitter will be exposed.
By experimenting with an SWR calculation tool like TLDetails, there appears to be a basis for this…
Glenn W9IQ
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10
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4 answers
What was the origin of the Morse code abbreviations "hi" and "es"?
In Morse code, hams use "hi" to indicate a laugh, and "es" to mean "and".
Where did these abbreviations come from? Both being all dots, they are short and easy to send and easy to recognize, but why these particular abbreviations?
For example, we…
Michael Geary
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10
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How can I do direct digital synthesis of a 630m WSPR signal?
I want to do direct digital synthesis of a 630m band WSPR signal.
Specifically I'd like to use an Atmega 328 chip running at 20 MHz to produce such a signal.
I will use standard phase accumulator algorithm which I believe I can get to run in less…
Eric Urban
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