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1500 questions
12
votes
1 answer
What do the three-letter modulation codes (emission designators) stand for?
I've seen these weird three-letter modulation codes like J3E, A3F, A1A, F3E and so on. Someone even wrote 2K40J3E or 12K5F3E. What do these codes stand for?
user
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12
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5 answers
How does an antenna transform impedances along its length?
If I insert some impedance (like a loading coil, or a trap) at the base of a monopole antenna, the effect on the feedpoint impedance is easy to predict: the impedance is in series with the antenna, so whatever the feedpoint impedance was, the added…
Phil Frost - W8II
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12
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5 answers
Grounding a second-story shack with an outdoor antenna
My shack is on a second story, really far away from the house ground. To run a ground from my equipment to the outside/ground is a run of at least 60-75 feet. The antenna is at least 100 feet away as well.
How do I ground this system? I cannot reach…
Jay
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12
votes
4 answers
Are antennas circuits?
For an antenna to work, doesn’t charge have to flow through it? A current must be present. To me it indicates it must be a circuit, but how is a dipole a circuit?
If they are not circuits, then how does charge flow in them?
mikew
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12
votes
1 answer
How do I discover APRS coverage?
I'm considering adding simple APRS transmitters to my vehicles. I'd rather just put one in and forget about it, but I understand there are areas of the US where a stronger transmitter would be required to successfully send an APRS update…
Adam Davis
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12
votes
2 answers
Why do Amateur Radio organizations in the United States oppose the relaxation of encryption prohibitions?
I saw this question stating that it is illegal to encrypt traffic, at least in the US and UK. I also heard that there was recently an attempt to get the FCC to loosen this restriction, but a lot of hams argued against it. Why do Amateur Radio…
Dan KD2EE
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12
votes
3 answers
Protect rig from static charge on antenna
How can I continuously discharge static from my end-fed antenna?
My Electraft K2/100's autotuner (schematics) has an SWR bridge using two 1N5711 pin diodes. These diodes get blown if any static builds up on the antenna. I've replaced them four…
Wayne Conrad KF7QGA
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12
votes
4 answers
Hearing Morse code after end of session?
Does anybody still hear phantom Morse code in your brain after ending a session? I'm hearing random beeps that definitely don't come from an external source.
I tried to search Google but couldn't find anything on this topic.
itsaunix
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votes
1 answer
What is a "roofing filter"?
What are roofing filters? Are there different kinds of things that are called roofing filter? Why would a circuit or component be called a roofing filter instead of just a IF bandpass filter? Why is the word “roofing” used? (as it seems to have…
hotpaw2
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12
votes
3 answers
Share antenna between receiver and transceiver?
I recently put up a fan dipole for 80/40/20/10. I'm looking for a way to share this antenna with a receive-only SDR and my shack transceiver. Obviously I can just switch this antenna between the two manually, but I was hoping there was a way to have…
s3c
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12
votes
4 answers
Can a ham license be used for a job?
If you get a ham license, can you, later on, get a job with that license, or at least display it on a resume? Or are there further licenses after ham radio licenses?
hopefulhacker-Reinstate Monica
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12
votes
3 answers
What is the decimal in Morse Code?
The ITU's International Morse Code recommendation ITU-R M.1677-1 specifies a "Full stop (period)" as ".−.−.−", however it falls short of specifying a decimal point. Even the examples, though they illustrate fractional numbers, don't show decimal…
Amin Shah Gilani
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12
votes
1 answer
Dominant speeds of Morse Communications
5 wpm is easy to learn and better than nothing in emergency.
Speed Morse Coding is fine for "sport competition"
I am trying to find out which is the typical speed for what I call "conversation" and define it with the following questions:
Are there…
03525
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12
votes
3 answers
How is "clarifier" control helpful?
My radio-club recently got a Yaesu FT-225RD transceiver and I'm trying to digest its manual (available for download here). This is the first ham radio that I'm learning how to use, so I could be missing something obvious.
On the front panel there's…
AndrejaKo
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12
votes
1 answer
Who funds amateur radio satellites?
I am currently studying for my Technician Exam and I am amazed at the sheer number of amateur radio satellites in orbit. Knowing how expensive it is to launch something into space, and assuming there is very little return on investment concerning…
Dave G
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