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1500 questions
4
votes
2 answers
What does the FCC do with confiscated equipment?
When a station is repeatedly violating FCC rules, transmitting out of band etc, equipment may be confiscated in addition to the fine. I am sure they have collected a large chunk of inventory from violating hams, pirate radio stations, kilowatt CB…
Skyler 440
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OFDM spectrum, HACKRF, and GNUradio companion
I am trying to analyze the spectrum of wifi spectrum.
I getting a good OFDM spectrum with my HackRF at 2.412 GHz (from my first QTGUI Sink).
But I get nothing out of OFDM Receiver. I was wondering why. Any help would be appreciated.
Jack
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4
votes
1 answer
How many frequency channels are there in a frequency band?
I've often heard people saying that 4G uses the 1800 MHz band but precisely what all frequencies does it work upon? Does it mean that is just uses one frequency i.e. 1800 MHz, well in that case wouldn't there be interference among signals carrying…
Shivam Aggarwal
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4
votes
1 answer
SDR with the Raspberry Pi
I wanted to explore digital modes by connecting a Raspberry Pi via audio cables to a transceiver. However, I realized that thanks to the clock generator, the raspberry pi can produce RF signals directly. Adding a square to sine wave converter, a…
Edgar H
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4
votes
1 answer
Steel Directors with Copper DE
I found old plans for a quagi that uses copper for the Reflector and Driven Element and any 1/8" metal available for the directors. The general recommendation for antennas is: no steel for the DE. Is it OK to use for the directors, and OK to 'mix'…
Mein Tenah
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4
votes
4 answers
Why does an "electrically small" antenna have narrow bandwidth?
Reading this interesting piece on magnetic loop antennas, the author explains that a magnetic loop has great efficiency even at small size, but the the price you pay is very narrow bandwidth. Why is this?
It seems counter-intuitive (and miraculous)…
bcattle
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4
votes
2 answers
How to determine a serial number in cq contest?
What serial number is referred to in a cq contest? How do I determine that serial number?
Louis Stannard
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4
votes
1 answer
No stations on MW band at daytime
I have a portable radio which serves for FM / MW / SW bands. At nights I can listen to 4-6 international channels from different countries on MW. However, I am unable to tune them at daytime. Is it about my location as a result of earth's spin or…
Karel Capek
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4
votes
1 answer
why do some radios have two fuses in the power leads
On a number of fairly modern rigs I've seen that both power leads are fused:
Why is this still so?
Does this have something to do with some vehicles having a ground-positive system or is this simply a forgotten relic that needs to disappear as…
captcha
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4
votes
1 answer
Bonding of Coax shield to RF ground conductor for long ground runs?
My shack is on the second floor of my home, and I run a single operator, 2 radio contest setup. The two coax runs pass through the wall and drop down to an antenna switch approximately 15 feet from the radios.
The ground system consists of multiple…
Hamsterdave
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4
votes
4 answers
Is it normal for mini shortwave radios to not have any reception in a major city?
I'm new to radios. Just bought the mini Eton which has FM/AM/SW and while FM & AM work I have never received a single station on SW1 (5.9 - 10 MHz) or SW2 (11.65 - 18 MHz). Is that normal? Will shortwave only work in Europe? I'm in Canada now. If…
verve
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4
votes
3 answers
Calculating bandwidth of antenna?
Is there a way to calculate bandwidth of an classical dipole antenna having this information:
center frequency
wire velocity
wire diameter
I would disregard antenna height, to simplify.
I am not targeting high precision calculation, just rough but…
Pedja YT9TP
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4
votes
3 answers
How can one convert from Grid Square to Lat/Long?
Can someone explain how can get the Lat/Lon of a given Grid square? (the middle of the grid would be the best).
I've looked at this (that does the "reverse"...from lat/lo to grid"):
How can one convert from Lat/Long to Grid Square?
But i need to do…
4
votes
3 answers
Is there a preferred order for learning Morse code using the Koch method?
The Koch method of learning Morse code is based on the idea that you learn characters at full speed, but a reduced set of characters that is expanded over time, instead of learning the full set of characters from the beginning at reduced speed and…
user
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4
votes
1 answer
How to calculate effective isotropic radiated power apply to lossy antennas
If a band allows one watt EIRP and I have an antenna that is 1% effective could I legally run 100 watts into the antenna because only one watt is radiated?
If that same antenna also has a gain would I then have to include this as well in the…
Arthur
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