Questions tagged [history]
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34
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What is an undulator (as used for CW)?
There are historical references to a device called an "undulator" used for CW reception circa before and during WWII.
What is an Undulator (as used for CW recording)? How did they work (...
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4
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What was the first QSO by an astronaut? Was it code or voice?
Discussion under this answer to Could amateur radio operators or others contact the ISS against NASA's wishes? in Space Exploration SE explore some activity from the Mir and ISS stations and the Space ...
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3
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Why do so many hams prominently display their callsign in the shack?
By ham standards, I'm far from being a long-time adept of amateur radio, but I've seen my fair share of shacks, both on the internet and in person.
What's always attracted my attention is that almost ...
- 459
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What band did walkie-talkies use in Europe before PMR446 was allocated?
The PMR446 band, now used for walkie talkies in Europe, was only allocated after 1997. I'm sure walkie talkies existed before that. What radio bands did those use?
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Why do operators mention the band when calling CQ on phone?
I'm a new-ish ham, licenced for about one year now.
Within that year I've heard a lot of CQ calls from other hams on phone (both HF and VHF), and it seems that a large portion of hams routinely ...
- 459
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Hardened UHF Antennas
Minuteman missile silos used an interesting hardened UHF antenna.
What kind of antenna is this? Does anyone have a drawing with a cross section?
Edit:
Jay Moore added a picture to a different type of ...
- 91
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2
answers
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Tuning two antennas using wire length
I've heard that in the early spark-gap wireless telegraphy era people would use kites with a wire acting as antennas and if the receiving side had a wire length that was an even division or multiple ...
- 47
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What do old unit abbreviations like "mfd" and "kc" mean, and where did they come from?
I saw a recent answer that mentioned "mfd" as a unit of capacitance, and I can recall having seen that term in old schematics and ham radio articles. I've also seen other non-SI unit ...
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How did SMA connector size become standard?
I'm working on a project in microfluidics and it has become apparent that a significant challenge to overcome is a lack of consensus in connector design.
I have been thinking about my time working ...
- 13
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3
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What replaces the T/R switch in modern transceiver
I have been watching and reading about the time when receiver/transmitter were separated and T/R switches were used. Current transceivers are still sharing a single antenna to transmit and receive. ...
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What would a "crystal mixer" have been in an 1960's radio telescope at 960 MHz?
In a paper cited in comments to this answer to In the 1950's how were radio-astrometric positions with portable dishes so precise they could be assigned to their dim optical counterparts (Quasars)?
...
- 543
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Looking for a book that contained a circuit for receiving (literally) underground amateur radio transmissions
In this comment in Earth Science SE I've said:
This is a really cool question! I remember (a long time ago) reading about electromagnetic waves inside conductive soil that travelled near but below ...
- 543
7
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1
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257
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What exactly was a decremeter and how did they work?
In A Century of WWV, I found this mention of an unusual sounding instrument that may have once been commonplace:
Calibration work was mainly focused on decremeters, instruments designed for ...
- 7,421
3
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What is this military radio?
Please help me identify this piece of equipment. It looks military spec, but don't know anything about it.
I want to look up some history about what it was used for.
Here are more photos.
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Is the Relay in ARRL still relevant?
The second R in ARRL stands for Relay, but is that still as relevant in the 21st century?
Has it been relevant since broad damped-wave spark transmitters were supplanted with tube-generated CW, which ...
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