Use this tag for questions about which frequencies to use or not use in certain locations/situations.
Questions tagged [frequency]
126 questions
51
votes
5 answers
How do I report an emergency using ham radio?
If I'm in the wilderness with ham equipment but no phone signal, how would I report an emergency? Is there a particular frequency I would use, a particular protocol or suchlike?
berry120
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What does a SSB frequency actually indicate?
An SSB signal is an AM signal with the carrier and other sideband filtered out, if I understand correctly.
As such, when specifying an SSB frequency do you specify the carrier frequency, then state which sideband, or do you specify the frequency the…
Adam Davis
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12
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5 answers
What is the difference between channel & frequency & band in RF?
I am reading about wireless networks basics. I found three terms I cannot find exact definition for: channel, frequency band, frequency.
Can anyone give exact definitions for them?
ashok
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11
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2 answers
Why do some DX listen on a different frequency than they transmit on?
I've heard some DX indicate "CQ up 5" for instance, indicating that they are listening on a different frequency than they are transmitting on.
What are the reasons one might want to do that?
Adam Davis
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9
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2 answers
What is a "calling frequency"?
Doing some study for the ham test, I read a question asking about a certain “national calling frequency”.
What is a “calling frequency”?
What is meant by “calling” in this instance?
SunSparc
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9
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5 answers
Why do Hams refer to bands by wavelength and not frequency?
I've noticed while reading literature and websites geared towards and written by amateurs and ham radio enthiuasts that frequency bands are commonly referred to by wavelength.
In professional environments I have been a part of, we always used…
YetAnotherRandomUser
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9
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1 answer
Antenna size for wideband
I just bought a SDR dongle that comes with an antenna. The dongle is for DVB-T.
The antenna is very small but the specs say that the dongle can go 30Mhz to 850Mhz.
From my knowledge of antenna physical size should be 1/4 the size of the…
Martin Naughton
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9
votes
4 answers
How can you calculate the frequencies for each band?
I've just started studying for my HAM license a couple of weeks ago, so please excuse me if this is a remedial question...
I have the Canadian Amateur Radio Basic Qualification Study Guide (which I'm finding is terribly hard to understand). Their…
BenAlabaster
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9
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1 answer
Why are radio frequency ranges aligned on multiples of 3?
Why are the radio bands organized by multiples of three?
For example the HF band is from 3–30MHz and UHF is from 300–3000MHz. Why not multiples of 2? Or plain powers of ten?
natevw - AF7TB
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9
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2 answers
Why do the ham radio bands get broader with increasing frequency?
The ham radio frequency allocations tend to comprise a larger frequency range for increasing frequency (also see this plot). For example, the 40 meters band is from 7,0 to 7,2 MHz, thus 200 kHz, while 23 centimeters is from 1240 to 1300 MHz, thus 60…
koalo
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8
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1 answer
Why is 9 kHz the lowest frequency for spectrum analyzers?
I researched a number of spectrum analyzers and it seems that the lowest frequency that these operate at is 9 kHz.
Why is the lowest frequency supported by spectrum analyzers 9 kHz?
kittygirl
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8
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1 answer
Why are there no amateur allocations in the LF and VLF spectrum?
Amateur radio enthusiasts have slices of spectrum at every magnitude of spectrum MF and above, but in the US none are below MF.
Why are there no spectrum allocations below 160M?
Adam Davis
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8
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2 answers
What will I need to receive the ICE/ISEE-3 transmitter?
The ICE/ISEE-3 spacecraft, launched in 1979, is due to pass by the earth in August, 2014. It was commanded to power down completely years ago, but it appears to have failed to do so, and while it could be re-tasked to perform another mission…
Adam Davis
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8
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1 answer
Is the bandwidth of an LCR resonant circuit independent of the capacitance?
Is the bandwidth of an LCR resonant circuit independent of the capacitance, if the inductance and its series resistance are kept the same, and the Q is high?
This question and the calculation associated with it were originally posted by a radio…
Harry Weston
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8
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3 answers
What is the permissible frequency error for US amateur radio transmissions?
What are my requirements as a licensed Amateur Radio operator in the US to keep to a single frequency? How much drift can I have during transmission and still be within my license? Does it depend on the mode or band? Note that I'm not asking about…
Adam Davis
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