Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

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1500 questions
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How to build a balun transformer for 2m RX with low insertion loss

I'm looking into ways to match a 137MHz RX dipole antenna to an unbalanced coax + amplifier. I know there are several types of baluns which can be categorized under magnetic baluns (where there are separate primary and secondary windings) and…
Felix S
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How to programmatically distinguish European from non European call sign?

Any ham radio log processing app developers? I am creating web application to manage our club award and I need to programmatically distinguish European from non European stations by call sign. I cannot find viable solution so any hint is valuable. I…
Pedja YT9TP
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What might this tower be used for?

This tower is located on the campus of my wife's employer. She's asked around but no one seems to know the purpose of it. Does anyone have any idea what this may be used for? Edited to add Additional Information: This tower is located on a…
Lance
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Noticeable difference between trunk and roof mount?

Between trunk-mounting and roof-mounting a 2m/70cm antenna, both as through-hole NMO mounts, is there really that big a difference performance-wise? I mean, I know roof mounting is better, but let's face it: looks are a factor for some of us (and…
Dominick Pastore
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Can I use a CB antenna with a ham radio?

I just passed General and purchased a FT-450D with an internal antenna tuner. While my ultimate plan is to use a G5RV, it will be a while before I can get it up. What modifications would I need to make to use a mag mount CB antenna. Would it work…
Adam KC0DAD
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How to transmit images and video through a hurricane?

Background You're in the path of a hurricane, and the eye just passed over your head. There is no electricity (apart from your own generator or battery), there is no mobile network and there is obviously no internet availability. But you do have a…
not2qubit
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My Baofeng UV-5RV2+ will receive a signal with rubber duck antenna but not with a new Nagoya

I bought my self a Baofeng UV-5RV2+ as an inexpensive way to introduce myself to the world of ham radio. With all of the stock components everything has been working fine. I wanted to try to increase the radios performance so I purchased a Nagoya…
T12mack
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HF Noise Level S5 to S9+18

Since I got my HF radio a year and change ago, I've been able to hear very little except noise and the WWV time station on 10MHz. Noise seems to vary by band, but not how I'd expect: 80m: S7-S9 40m: S9+10-20 20m: S2 15m: S3 10m: S9 6m: S5 My setup…
William
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How often are we required to send our callsign?

Amateurs on the radio and online tell us we MUST ID at the start of our transmissions. A couple of hams on 75m sometimes take me to task for not saying my callsign right away. 'The FCC says so'. Is that true or not?
Mike Waters
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I am installing a ham radio and want to properly ground it

I am installing a ham radio and want to properly ground it. I will be including a lightning arrester that will also go the the ground. I will have a 20' mast with a long wire antenna running 130+ feet out to the south. The far end will be about 45…
Chris Baker
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3 answers

HF antenna design for high-altitude balloon

I'd like to put a WSPR or JT65-like transmitter on a high-altitude balloon, but lacking much experience with HF antennas, I don't quite know where to start. I'm thinking it will operate on 20 meters, at (obviously) low power, say 100 mW or less.…
Rodney Price
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Detecting signals using statistics

I have sampled a section of spectrum every few Hz. I have mean, standard deviation, and range data for every frequency sampled (and I can gather more statistics if necessary). I've sampled for several seconds before storing the spectrum…
Ken - Enough about Monica
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When should an adapter be used to marry a coax to a connector?

A quick follow-up to What should I consider when choosing a coaxial cable? Most commercial rigs come with a PL259/SO239 connector for use with something like the RG8/RG11. In the event the diameter of the cable used is significantly smaller; say…
VU2NHW
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Tiger Tail + capacitive coupling... what's the interaction?

I've been working on a 2m setup for hiking. My goal is to have the best possible antenna that can be used while walking, and that won't get damaged if I walk under a low branch or some other forest obstacle. The setup so far: Off the top of a…
Dr Marble
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AX.25 on macOS (aside from APRS)

I'd like to send raw AX.25 packets from a macOS PC using a KISS TNC (mobilinkd TNC2). I've sent APRS packets with this set up using Xastir, but I'd like to send other information besides just APRS (i.e. put my own information into the AX.25…
watkipet
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