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1500 questions
17
votes
4 answers
Are amateur radio call signs unique among all radio call signs?
Idle curiosity:
Are the call signs of amateur radio operators distinct from call signs in all other radio services, such that there can be no ambiguity even if the relevant license and band(s) of operation is disregarded?
If they are not distinct…
Kevin Reid AG6YO
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17
votes
2 answers
Is free space path loss dependent on frequency?
Free space path loss is calculated as:
$$ \left( 4 \pi df \over c \right)^2 $$
The presence of $f$ in this equation means that losses increase with increasing frequency, so there's an inherent advantage in lower frequencies, right?
Phil Frost - W8II
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17
votes
2 answers
Why is the solar-flux index measured at 10.7 cm?
Why is the solar-flux index measured at 10.7 cm? What makes that such a special frequency?
Dan
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17
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3 answers
Why are proprietary codecs used in amateur radio?
This may be slightly off topic (maybe there's a Legal Stack Exchange :-D), but how is it that codecs like Yaesu's C4FM are allowed to be proprietary while still being used on Amateur bands? At the very least, this does not seem to be in keeping with…
Joshua Nozzi W4JLN
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17
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8 answers
Should I chose a vertical or a horizontal HF antenna?
If I only have the budget for one HF antenna, should I chose a vertical or a horizontal antenna?
Timtech
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17
votes
5 answers
If I receive an SOS signal, what is the proper response?
My 5-year old son loves sending out an SOS signal using a toy Morse code generator (wired, don't worry about false alarms for real authorities).
He has learned to send the SOS signal and was asking me to send a response to him to let him know that…
Hanky Panky
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17
votes
4 answers
Understanding coax impedance
I keep doing research, and trying to grasp it, but when it comes to RF impedances, and coax, I still have trouble trying to grasp it.
So first, I think you have to have a 50 ohm coax for a 50 ohm transmitter to keep the impedances matched. I think I…
Skyler 440
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17
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3 answers
Why do we not use AM and FM at the same time to transmit more information?
Amplitude modulation uses the modulation of the amplitude of a carrier wave to transmit data while leaving the carrier frequency constant, and in the case of FM it's just the other way round.
Why is a modulation of the frequency in an AM signal not…
DK2AX
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17
votes
5 answers
Can a licensed ham use or modify CB equipment to work the 10 Meter Amateur bands?
Can a licensed ham use or modify CB equipment to work the 10 Meter Amateur bands? If so, are there any advantages/disadvantages to this?
Timtech
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16
votes
3 answers
What's wrong with 220MHz?
It seems like 220MHz is the bastard step-child of the amateur world. Every HT is either 2m or 2m/70cm. Some companies offer tri-banders, but they almost always add 6m (?!), not 220MHz.
The only way to get this band easily is the Chinese radios. I…
WPrecht
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16
votes
7 answers
What is the cause of this unusually long period of terrible HF band conditions?
I've been a ham for over 40 years, but never has there been such a prolonged period of such poor propagation. This has been especially the case over the past six months or so, and they continue to deteriorate.
What could possibly be the cause?
This…
Mike Waters
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16
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12 answers
How can I safely transmit without an antenna tuner or SWR meter?
Just what the title says.
An Antenna Tuner, henceforth AT, is almost a de facto piece of equipment in a shack; working the bands without one is tantamount to leaping off the diving board into a swimming pool with tarantula nests in it ... or…
VU2NHW
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16
votes
2 answers
How does selecting the opposite sideband when receiving CW on HF reduce interference?
I am studying for my FCC General Class license, and question/answer G4A02 reads as follows:
Q: What is one advantage of selecting the opposite or "reverse" sideband when receiving CW signals on a typical HF transceiver?
A: It may be possible to…
Bryson
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16
votes
3 answers
Why does SSB have the hollow voice sound?
When I listen to SSB, it has the very familiar tunnel-voice sound. What properties make it sound like this? With a Carrier and an extra sideband as AM, I don't hear the tunnel-effect at all. Is there special equipment to get rid of the effect?
Skyler 440
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16
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4 answers
OK to use any repeater?
There are a number of repeaters in my area, each belonging to a particular amateur radio club. These guys are all friendly and willing to chat but I was wondering if it was bad form to make use of a repeater belonging to a club you aren't part of…
s3c
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