I grew up listening to shortwave radio. I learned how to make antennas too. The proper length of antenna and electrically shortening or lengthening it with a capacitor or inductor. I would also learn how to take a #balun and make covert directional and #yagi antennas, something that might be very important if signals are jammed during a total fascist takeover. Cable, connectors, and makeshift insulators and RF iron cores, stocking up on these DIY antenna parts might be quite useful during the dark days ahead. Also, learning #MorseCode never goes out of style.
#Balun
Looking at the next project after our PSU and was looking at a I/O solution using balun line drivers/receivers. Here's my first pass.
2HP Eurorack I/O panel for the front. 4HP panel (for cases like ours that have rear slots) for the line-level I/O.
I want to make a version that uses transformers too but those will likely be $$. Has benefits (like ground isolation) though so I'm looking to see what the price might be for those.
#Eurorack #Modular #Balun #LineDrivers #KiCAD
2HP Eurorack I/O panel for the front. 4HP panel (for cases like ours that have rear slots) for the line-level I/O.
I want to make a version that uses transformers too but those will likely be $$. Has benefits (like ground isolation) though so I'm looking to see what the price might be for those.
#Eurorack #Modular #Balun #LineDrivers #KiCAD
And this is how you can measure your choke aka Ugly Balun with a quick and dirty solution. VNA set to Logmag.
I can't find for sale anywhere a 1:4 #balun for HF. It is for a low height 40m inverted V #NVIS #antenna. Military versions such as #AS-2259 use the custom coax support pole as an impedance transformer.
To be clear, I mean 12.5 ohm balanced antenna side to 50 ohm unbalanced coax side. The ones for sale on eBay/Amazon seem to be mislabeled 4:1 ones.
Making one isn't an option: my hands don't work properly.
Anyone any ideas.
Baluns & Ununs: The Unsung Heroes of Antenna Building and Signal Matching
758 words, 4 minutes read time.
When diving into the world of antenna systems, whether you’re a hobbyist or a professional, you might often hear about Baluns and Ununs. These are specialized transformers that play pivotal roles in signal transmission. Their primary function is to match impedances between components in your system to ensure the highest efficiency and performance. But what exactly are they, and how do they contribute to antenna building?
What Is a Balun?
A Balun, short for BALanced to UNbalanced, is an electrical transformer that allows the connection of a balanced load (like a dipole antenna) to an unbalanced feed line (such as coaxial cable). It’s a key component in matching the impedance between these two differing systems, ensuring that signals are transferred without significant loss. Baluns are widely used in radio frequency (RF) systems to ensure minimal signal reflection, noise, and interference.
Baluns come in various configurations, depending on the specific needs of the system. They can handle impedance transformations with ratios like 1:1, 1:4, or 1:9. The type of balun you choose depends on the specific characteristics of your antenna and feed line. For example, a 1:1 balun keeps impedance consistent, while a 1:4 balun is typically used to match a 75-ohm coax to a 300-ohm antenna.
Additionally, there are different types of Baluns, such as current baluns and voltage baluns. A current balun is used to block common mode currents, while a voltage balun balances the voltages on the antenna.
What Is an Unun?
An Unun, which stands for UNbalanced to UNbalanced, is another crucial transformer, but it serves a slightly different purpose. While a balun connects a balanced antenna to an unbalanced feed line, an unun matches impedance between unbalanced components. It’s commonly used with antennas like end-fed half-wave (EFHW) antennas, which are often unbalanced in nature. The unun’s job is to ensure that the impedance of the antenna matches that of the transmission line, reducing signal reflections and losses.
Ununs are typically used in situations where both the antenna and transmission line are unbalanced but have different impedance values. For example, a 1:1 unun might be used to match a high-impedance antenna, like an EFHW, to a coaxial cable. The most common configurations for ununs are 1:1 or 4:1, but just like baluns, the specific ratio needed depends on the application.
The Key Differences Between Baluns and Ununs
While both baluns and ununs serve to match impedance, the key difference lies in what they connect. A balun bridges the gap between a balanced antenna and an unbalanced feed line, whereas an unun is used for matching different impedances between unbalanced components. The choice between a balun and an unun largely depends on the antenna system you’re working with. For example, for dipoles or Yagi antennas (which are balanced), a balun is typically required. For end-fed antennas, an unun is more appropriate.
Why Are Baluns and Ununs Important for Antenna Performance?
Impedance matching is vital in any antenna system, and both baluns and ununs make this process possible. Without proper impedance matching, your antenna system could suffer from inefficiencies such as signal loss, poor radiation patterns, and mismatched power transfer. By using the correct balun or unun, you ensure that the antenna system operates at peak efficiency, minimizing reflections and maximizing power transfer.
Furthermore, these components also help in reducing common-mode currents that could otherwise introduce noise and distortions. Whether you’re dealing with high-frequency signals in amateur radio or broader RF applications, a well-matched antenna system ensures cleaner, stronger signals.
Practical Applications and Tips
When building or designing an antenna system, consider the following practical tips:
- Choose the right impedance transformation ratio: Whether you’re using a balun or an unun, selecting the right ratio (e.g., 1:1, 1:4, or 1:9) will significantly impact the performance of your antenna system.
- Select the right materials: Baluns and ununs can be made from various core materials like ferrite, powdered iron, or even air. The choice of core material can affect the device’s efficiency, especially at higher frequencies.
- Use for noise reduction: For systems prone to interference or common-mode noise, a balun (particularly a current balun) can help to suppress these unwanted signals.
Conclusion
Baluns and ununs might seem like small components in the grand scheme of antenna building, but they play an essential role in ensuring your antenna system performs optimally. Whether you’re setting up a dipole antenna, a Yagi, or an end-fed wire, understanding the role of these transformers will help you make the right decisions for better signal transmission, reduced interference, and overall improved antenna performance.
D. Bryan King
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#11Balun #41Unun #antennaBuilding #antennaEfficiency #antennaPerformance #antennaSignalMatching #antennaSystems #balancedAntennas #Balun #coaxialCable #coaxialTransmissionLines #commonModeCurrents #currentBalun #dipoleAntenna #endFedAntenna #impedanceMatching #impedanceTransformation #noiseReductionInAntennas #powerTransfer #radioFrequencySystems #RFTransformers #signalInterference #signalLoss #transformerDesign #unbalancedAntennas #Unun #voltageBalun #YagiAntennas
Angélica Negrón (1981-)🇵🇷 is a Brooklyn, New York based Puerto-Rican composer, writer, multimedia artist multi-instrumentalist, and music educator. She is is currently a teaching artist for New York Philharmonic’s Very Young Composers program and also part of the electronica/dream-pop band Balún who can be heard on NPR’s Tiny Desk in 2020 (https://youtu.be/YZ2iWUyT_DI?si=pcHjRoNZHtWihNt7) and KEXP in 2018 (https://youtu.be/tzXnUaO2rRY?si=bG_hgZa76dwr_UX6).
#SymSat #HispanicHeritageMonth #AngelicaNegron #Balun
last update tonight -- finished the 4:1 balun
all that's left to do is is get wires up in the air and connect everything up
Current-Based Side-Channel Attacks, Two Ways https://hackaday.com/2024/01/04/current-based-side-channel-attacks-two-ways/ #ReverseEngineering #cryptography #Sidechannel #current #balun #ESP32 #shunt #aes
Denke den Balun habe ich ganz ordentlich und sauber aufgebaut.
Jetzt braucht es noch Werkzeug damit die PL-Buchse eingebaut werden kann
#hamradio #amateurfunk #darc #unun #balun #antenna #kurzwelle #shortwave
Saw an amazing #PuppetShow collab last night with #Balún and #PonciliCreación - and immediately thought @ancient_catbus would be into this sort of #shoegaze #fuzeboxfestival #Explosioncita
Does anyone have experience with #hdmi extension technology like #Balun, #HDBaseT, or KVM Extender over IP?
I have a house wired with point-to-point cat6, and I'd like to move all my AV junk to the basement. It'd be great if I could run it through a switch but it's unclear to me what tech allows for that.
I also took care of this thing throughout the weekend. It is an MFTF UnUn #Balun with multiple transformation connections. Despite of what the label claims, it could not do 150 watts as the ferrite core was getting hot with half the power. I would have expected more when paying for that thing. I still have to try that fix.
I build a small test bed to play around with #UnUn (#Balun) in this case a 1:9 UnUn. With a 440 ohm resistor you see plugged in, this one is a perfect dummy load on all HF bands as expected.
Started getting high SWR from this "magitenna" a while back. Damaged the case investigating it so ended up replacing the case and so239 socket.
The before and after (pictured) look the same more or less, but still getting very high SWR over 3:1 on ham bands.
Feed lines and antenna wire check out OK so leaves the #balun at fault but what are the variables here? Ferrite gone bad? Wires slipped out of position? Not sure where to start diagnosing this, any ideas? #hamradio
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