Recently Active Questions
4,999 questions
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What is this signal?
https://drive.google.com/file/d/1pCUDjJbDJVGmmnhp-jYk_vXjfm_KxK6V/view?usp=sharing [18kb .m4a file] (Note: The file was edited to remove the 30 seconds of silence between bursts.)
Heard on 7-May-2025 ...
- 949
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How to match 5w radio output to 0.005 watt input on amplifier
Found a 50-ish watt amplifier kit online that looked like a good challenging build.
It says it provides 40dB of gain, and specifies maximum input power of 0.005 watts.
The candidate radio I'd like to ...
- 2,610
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Does a transceiver radio have a "receiving range"?
I'm familiar with the fact that a transceiver radio has an effective transmission range that is affected by several factors, such as the antenna, transmit power, obstacles, etc. I'm wondering if a ...
- 274
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Hopelessly Lost on BFO Island
I am picking up some low ssb somewhere I think on the 160meter band (1800 -2000 khz) on one of my homebrews. I can also pick up much higher ssb bands, but this low stuff I was concerned because I ...
3
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2
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Linking DStar repeaters using Icom syntax
I would like to monitor a remote repeater (VE2RM) through my local repeater (VE3TTT). I am trying to figure out how to link them - specifically using the Icom ID-52A commands/syntax. I found some ...
CommunityBot
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Reverse protection for PA
I am designing an RF transceiver for TX RX at 435MHz. I have the module working fine without any issues with PA TX at 2W.
The only issue is the reverse power from the antenna if both units are placed ...
- 2,610
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Capacitance between two parallel wires with a cylinder of a dielectric added
A open twin feeder or a Lecher line is two parallel wires, both the inductance per meter and the capacitance per meter affect the impedance and the velocity factor of the line. While the polythene of ...
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dBi gain of random wire antennas
All antennas are a compromise. Are there any antennas that in free space perform strictly worse than an isotropic antenna would? Or a simple flat ground model?
This is what has been bugging me. I am a ...
- 1,002
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Ferrites losses calculation
I am new on RF design. I would like to know more about ferrites. I am looking for information about how to calculate ferrite losses and saturation points for a given application. I also would like to ...
CommunityBot
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Midland G7 Pro charging voltage (Ni-MH battery)
I've found contradictory information about the voltage and current fed by the original charger (using a PB/ATL-G7 Ni-MH battery), and I'm trying to use a generic one through its mini-jack port, ...
CommunityBot
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Yaesu ADMS-13 software: open saved file without reading config from radio first?
I recently purchased a Yaesu FTM-6000. I like the radio, and I'm happy that the ADMS-13 software runs under WINE without a problem, but the software has some truly odd behavior and I'm wondering if I'...
CommunityBot
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Wiring Cobra 29LTD CB for home use?
I'm a beginner trying to use one of my two CB radios as a "base station." The problem is that the power cable is just two wires (no connectors/12v car plug) and a 2A fuse along one. Is it ...
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271
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Weakly directive VHF/UHF antenna
Most resources around the Internet discuss common antenna types, classifying them between directive (like Yagi) and nondirective (like a simple dipole). Directive antennas are good when you know from ...
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2
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Is this an unintended short circuit in my Moonraker GPA-80F vertical HF antenna?
I'm a newly licensed ham and purchased this Moonraker antenna from DX Engineering as my first HF antenna.
I noticed that there is continuity between the inside and outside of the SO-239 connector at ...
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The whole neighborhood's internet drops when I transmit on 40M
I recently built a vertical. It's 6M radiator, a coil, and 1.2M more of radiator. It sits on my roof, which is metal, and acts as a ground plane (GND from the feedline is connected to it). There is a ...
