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1500 questions
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How would you get an "I'm alive" message to family in another state using amateur radio?

I'm researching options for getting an "I'm alive" message during a disaster response out to family in another state that aren't HAMs. There are likely to be a lot of possible answers that are art and style rather than one "right" answer, so some…
Matthew Wetmore
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How big can an antenna be before I need planning permission in the UK?

Presumably setting up a 1m high antenna in a back garden isn't going to be an issue, but setting up an 80m high antenna would likely cause complaints! How high an antenna can I legally construct in the UK without going through the route of applying…
berry120
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Confusion about radio-computer interfaces: TNC, CAT, TRRS, Wolphi Link, ...?

This is probably a very simple and stupid question, but I'm getting more confused over time. Perhaps it is a matter of terminology, but a unified resource differentiating and explaining the different interfaces to connect radio with computer…
hamster
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What is Hinternet, in simple terms?

I've been reading about HInternet a bit, and all explanations I find are detailed technical explanations. I have no idea who pays for internet connectivity, where the internet sources from, etc. Just articles about the frequencies used and…
mr danker
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Decimation to listen to FM radio with gnu radio

I am trying to listen to FM station using an SDR and GNU radio. I have followed this procedure Is there a reason that the decimation is done gradually? For example would it make a difference if I change audio decimation to 1 in WBFM Receive and…
Jack
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Why aren't there baluns that do BOTH balanced/unbalanced transformation and common mode current attenuation?

I have read myself blue, about baluns. Especially 1:1 ones. Some claim they're only there to balance the unbalanced signal, and that's what's in the name also, but I find several that claims that the main thing at the point of a balun is common mode…
Hans Neve
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Is there a standard data format for station/channel/band information?

Does there exist a de facto standard data (file) format, or even several common formats, for representing information about radio stations, channels, and/or bands? I am writing software which would like to be able to make use of such data sets where…
Kevin Reid AG6YO
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What is the attraction of vertical antennas for HF?

I understand that MW broadcast stations use vertical antennas because that polarization works much better for groundwave propagation. But in amateur radio, I would assume the focus for communications on the HF bands would be via ionospheric…
natevw - AF7TB
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License upgrade - retake required?

It's been more than a year since I passed my Technician and General exams and obtained my license. If I were now to go for my Extra class license, would it simply be a matter of taking and passing the Extra exam, or would I need to pass the previous…
KD8TGR
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I have 60 feet of coax but only need 20 feet; can I loop up the excess?

I was given about 60 feet of good cable with connections but only need about 20 feet. Can I loop up the end or do I need to cut and put a new connector on?
Dant1316
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On Anderson Powerpoles, does the red on go on the left or right?

When attaching a red and black pair of Powerpoles together, which way should I do it to ensure that it will plug into the most number of other people's gear? When looking from the top of the connector (the side where the "tongue" is not visible)…
Arthur
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Battery sizing for power draw

Note that this question isn't about battery capacity, at least not per se. I have a 100 Watt mobile transceiver. At 12 V and assuming 50% efficiency, that means it draws a little under 20 Amps at full power. It's currently being powered by a pair of…
Dan KD2EE
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What exactly does an unun do to the impedance of a transmission line?

If I have a load Z_L and a length of transmission line with impedance Z_0 I know how to compute the impedance at the input to the transmission line (using smith chart or using telegraph equation). But now suppose I attach a 4:1 Unun to the (input)…
DrEntropy
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Is frequency hopping a viable solution for privacy and security without encryption?

In terms of radio transmission, three major issues seem to arise for various sensitive transmissions: Others do not gain access to the content of the message Others cannot determine the location of the sender Others cannot block (jam) message…
J-S
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Minimal info on a SWL QSL

Which is the minimal information I should require to confirm/QSL a reception report I receive ? I know the report must contain my callsign, time, date and band where I was listened. Is it also a requirement to indicate the callsign of the other…
joaquin
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