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1500 questions
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Will Icom HM-133 work on IC-2800H

I have been having problems with the knock off of Icom microphone so I figured I would bite the bullet and get a new Icom microphone, since the original is out of production. I found that HM-133 looks like a good candidate to replace it. If not what…
Darryl Wagoner
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What is an cheap and easy to build kit for a sw ssb transceiver?

I have a licence since I was 14 which is exactly half of my life, but honestly with the advent of the internet I somehow lost interest and sold my equipment. Now I really start to think, I should dive into it again, but I don't want to spend a lot…
Oliver Hankeln
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How to measure gain of an antenna?

I have dual stacked crossed yagi antenna. How can I practically measure the gain of the antenna combination? I know that this can be done in an anechoic chamber. But this is not feasible for me (transportation and cost). Please guide me. The antenna…
Vaibhav Rekhate
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Why exactly would cable lengths to a duplexer matter?

So a very experienced friend of mine is making a portable suitcase kit with Yaesu FTL-2001 (VHF), Yaesu FTL-7002 (UHF) and DX-720D duplexer* plus power supply and other miscellaneous gear. FTL-2001 and FTL-7002 are connected to inputs of DX-720D and…
AndrejaKo
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What is the aperture efficiency of an antenna?

For reflector antennas, I see a number called aperture efficiency. What does it mean?
Communicationantennas.com
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Why does the ionosphere reflect some frequencies and not others?

Why is it that some frequencies transmitted at some known direction are reflected back to earth, yet others transmitted at the same direction, power and polarity pass through into space with no reflection?
BenAlabaster
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Is Alaska considered to be located north of line A?

I recentley moved to Fairbanks AK, and was wondering if Alaska constituted being north of line A. Being that geographically, Alaska is north of line A, but in real world applications, Fairbanks is nowhere near Canada.
David Anastasio
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Connect Printed Yagi-Uda Dipole Array with Balun to coaxial cable correctly

I am making the Printed Yagi-Uda Dipole Array with Balun (that is the full name). I used Antenna Magus to calculate dimensions. I am not sure how to properly connect it to coaxial cable. Here is what the antenna looks like: In the Feed Method it…
Triak
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What are the continuous transmissions at the lower end of the spectrum?

I'm fairly new to amateur radio, and I've been using a web-based SDR tool in addition to my own radios. Using this SDR tool shows a lot of activity lower down on the spectrum, such as this: When I tune into it I hear a lot of odd sounds, some sound…
user9993
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How to feed coax from inside car?

What is the best (or standard) way to get coax from the radio in the car to the outside of the car without smashing it and damaging the line? If I just put it through the door crack, it seems to look pretty bad and I don't want to damage my new…
Skyler 440
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What if someone responds to my CQ, but I can't hear him?

I tried making a CQ on 20 m, 14.060 MHz (the QRP CQ frequency) and parallel to that I had a WebSDR on my computer just to keep an eye on the band. I saw someone responding on the WebSDR, which is rather close to my hometown; however, I couldn't hear…
user885
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1 answer

Images up and down the spectrum

I brought an rtl-sdr USB stick to a foreign country. I am listening with gqrx, and I am surprised to find audio (e.g. television or radio) up and down the spectrum, up to 600, 700 and 800 MHz ranges. I haven't experienced this in the States. I…
Ken - Enough about Monica
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Adapting an antenna coupler

I've built AA5TB's antenna coupler: I left out C2 because I didn't understand why I would need it - why would I? It works fine without. Unfortunately, when I started tuning for a 5W 20m transceiver, the LED was on all the time. I then measured with…
user885
5
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3 answers

Is it legal to use animal noise courtesy beep?

For Thanksgiving, I changed the courtesy beep to a turkey noise on my repeater/node. Some other people did it so I thought it was fine. Someone however told me that it did not follow part 97 FCC. Is this true?
Skyler 440
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Stacked shell inductor — what's its function/use?

I have a device of copper and iron (about 8 kg) which looks like two shell inductors joined so that there is some coupling but high leakage. The windings seem to be identical. Each is a single continuous winding with 4 intermediate taps. I did not…
Merlin3189
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