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1500 questions
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votes
1 answer
How does SDR demodulation differ between wideband and narrowband FM?
What is the difference between software demodulation of an IQ signal between wideband FM and narrowband FM? Both seem to look at the 2nd difference in unwrapped phase angles of IQ samples.
hotpaw2
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9
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Is steel or aluminum structurally a better material for catenaries?
I understand that steel is not a good material for antenna wire, but let's consider that I'm using the wire for purely structural support, or I am cladding it with copper to address the RF conductivity issues.
Then, which material is more suited to…
Phil Frost - W8II
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9
votes
3 answers
Impedance ratio vs. SWR
The specs of the Elecraft T1 tuner say, that it can match a 10:1 SWR.
What does that mean in terms of impedance ratio?
What antenna impedance can it match to 50 Ohm then?
Or is it not that easy?
Dominik Heidler
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2 answers
Can I use a amateur license to experiment with radar?
If I get a German Amateurfunklizenz, will I be allowed to experiment with non-communication radio technologies like radar?
Obviously, I'd still adhere to using allocated ham bands, stay within power budgets (solidly below), and identify.
The…
Marcus Müller
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9
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2 answers
How much current can Baofeng UV-5R provide on +V pin?
I noticed that the pinout for cheap Baofeng connectors has +V available. I'm interested in powering some electronics directly from this connector.
When unloaded, this seems to have about 3.3V on it, but when I try to power my load (an ESP32), the…
Evan Krall
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Does scanning take much more battery than listening on one channel?
I have a couple of HTs with channel scanning features. I imagine setting the radio to scan mode takes more power than just listening to a single channel, but what rough order of magnitude? Will I lose 1%, 10% or 50% of my battery life? Are some…
K0SWE
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What types of materials increase the inductance of a coil when inserted inside it?
I'm asking this because of the comments in this answer, that imply that steel (mostly iron) has similar characteristics to ferrite.
Specifically, it is implied that inserting solid steel into a single-layer coil (as is commonly used in an antenna…
Mike Waters
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9
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3 answers
How does contesting benefit Amateur Radio and its community?
Some use contesting for personal accomplishment, some out of pure enjoyment, others to gather awards, and some to hone their ability to work their craft. For instance, you may learn or improve your skills merely by contesting.
I'm wondering if…
Adam Davis
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9
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4 answers
What did it mean to "align" a radio?
I've heard older hams talk about "aligning" their equipment. E.g. "I sent it to a guy for alignment" or "that rig probably needs to be completely aligned before you use it".
As a kid, sometimes I remember broadcast AM/FM receiver dial indicators…
natevw - AF7TB
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9
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overhead power-line safety
A set of utility lines, and above them some high voltage power lines, run almost directly over the backyard fence. Some radio antennas are situated so that they can't fall onto the utility or power lines. However the opposite is not true. It…
hotpaw2
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9
votes
3 answers
RigExpert AA-35 - Interpreting The Information
I have a new RigExpert AA-35 antenna analyzer. 1st one I have had & 1st time trying to use an analyzer on an antenna. My questions are very basic and general, but I am having difficulty in Googling for answers. Hope someone can help, or direct me…
B. Varner
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9
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3 answers
In-house repeater?
At one time I was active in the local SKYWARN program, but then we moved and I find myself 10 miles from the local repeater. Given the various obstructions between it and me, I can't really hit it unless I'm up in the attic or on the roof. To make…
J_C_R
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9
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4 answers
Why does ladder line generally have a lower loss than coaxial cable?
It is well understood in the amateur radio community that ladder line, window line, etc. have lower losses per foot than say RG-213 or LMR400, particularly on HF frequencies. It is also understood that this loss is a function of the RF resistance of…
Glenn W9IQ
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9
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How many new amateur operators can currently use CW?
Given that it is no longer a license requirement, are there any current statistics available on what percentage of licensed amateur radio operators still learn Morse Code to some degree of proficiency? (e.g. without needing to use a computer…
hotpaw2
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9
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5 answers
What should I do if my call is being used by someone else?
I've been contacted by others who want to verify a DX with me, but I was not operating at that time! It appears that someone made several contacts using my callsign for a short window of time one day.
I've been keeping my ears open, but haven't…
Adam Davis
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