Knowledge Base: Guides & Technical Resources

Welcome to the Knowledge Base, your comprehensive resource for improving your understanding of antennas, RF systems, and station optimization. Whether you’re new to amateur radio or an experienced operator, this collection of articles is designed to provide practical advice, technical insights, and solutions to common challenges faced in antenna design, installation, and performance tuning.

The articles are divided into key categories to help you easily navigate through the topics that matter most to your station’s setup and operation.

Wire Antennas

1. Advice on Wire Antennas for Those with Limited Space
2. Does feedline length matter?
3. Fold-Back Tuning for Antennas: Guidelines and Best Practices
   
4. Tuning a Doublet Antenna: Methods and Considerations
   

RF.Guru End Fed Wire Antennas

1. End-Fed Antennas Explained
2. Using an Antenna Analyzer for End-Fed Antennas with Coax as a Counterpoise
3. Feed Point Impedance vs. Feedpoint Height Above Ground for End-Fed Antennas
   
4. Comparing 80/40 Meter EFHW Antennas: Inverted L vs. Sloper/Flattop for DX and NVIS Operations
   
5. Why the EFOC29 Design Outperforms the EFHW8010 and EFLW37 in Multiband Operation
   
6. The Challenges of Multiband End-Fed Half-Wave (EFHW) Antennas and Ferrite Losses
   
7. Why the EFOC17 is the Better Choice for 40M to 10M Operation
   
8. Comparing a 15m and 20m Mast for a Dual-Band 160/80m EFHW Inverted-L
   
9. Why RF.Guru Pushes Dual-Band EFHW for High-Power (3kW-4kW)
10. Why RF.Guru Recommends Only Inverted L for 160/80M and 80M/40M with 68-70:1 Transformers for end fed antennas
    
11. Why a (External) Tuner is handy to get more out of your (too short) wire antenna
    
12. Why We Won't Build the EFHW8010 Anymore
13. Optimizing End-Fed Antennas with High-CMR Chokes
    
14. Why RF.Guru Does Not Use Coils to Electrically Lengthen EFHW Antennas [NL]
15. Why an EFHW Inverted-L for 160m/80m outperforms a 20m long vertical with a Tuner
    
16. Why an EFHW Inverted-L for 80m/40m Outperforms a 10m or 13m long Quarter-Wave Vertical
    
17. Why We Primarily Use Full-Wave and Half-Wave End-Fed Antennas
    
18. Why an Antenna Tuner Is Essential When Using Multiband Wire Antennas with Solid-State Amplifiers
    
19. Why a Near-Resonant Antenna Like the EFOC29 Is Preferable to a Long Wire: EFOC29 vs. EFLW22
    

RF.Guru Active Receive Antennas

1. Comparison of Active RX Antennas
   
2. Why an Octaloop is Superior to a Square or Circular Loop Antenna
   
3. Understanding the Null of a Shielded Active H-Field Loop Antenna
4. Height vs. Performance: Optimizing the OctaLoop Active Magnetic Loop Antenna
   
5. Active RX and TX Antenna Proximity: Safe Distances and RF Protection
6. Safe Distance for Active Antennas from the Home
7. Mounting the Vertical Vortex
   
8. When Is a Rotator Useful on a Active Magnetic Receive Loop?
   

Product Related General Technical Articles

1. Why High Quality Polycarbonate Enclosures
2. Understanding the Visible Gap on Our Enclosures
   
3. Why Does RF.Guru Use PTFE-Tinned Stranded Copper Wire for Baluns Instead of Enameled Wire?
4. Stainless Steel Type 316: Properties, Benefits, and Applications
5. Correct Use of RF.Guru Antenna Tuner Baluns
6. Mounting Flanged Enclosures on a Boom, Mast, or Support Tube
   
7. Want to refer to us ?

Baluns and Ununs

1. The History of RF Transformers
2. A brief overview of BALUN types and their applications
3. A brief overview of UNUN types and their applications
4. The Guanella transformer (Current Balun/UNUN) explained
5. The Ruthroff transformer (Voltage Balun/UNUN) explained
6. The Autotransformer (Voltage Unun transformer) explained
7. The Hybrid transformer explained
8. Autotransformer vs. Ruthroff Transformer in UNUNs and BALUNS

General Technical Articles

1. The Importance of a High-Quality Common-Mode Choke or Line Isolator
2. SWR Demystified: Understanding the Real Impact of SWR on Your Station
3. Grounding Practices, Safety, Performance, and Regulatory Compliance
4. Ground, Grounding and SWR
5. Understanding Power Specifications: ICAS, CCS, and DIGITAL in Amateur Radio
   
6. Minimizing RF Noise in the Radio Environment
   
7. Optimal Common-Mode RF Current and Noise Elimination for TX antenna
   
8. Propagation Characteristics of Ham Radio Bands (2200m-2m) Mid-Europe
   

Frequently Asked Questions and their Answers

1. Common Misconceptions in Ham Radio
   
2. Is radiating resistance as important for RX antennas as it is for TX Antennas?
   
3. Why is Targeting Zero Reactance (X = 0) Important When Tuning an TX Antenna?
   
4. Is a TX antenna (with high radiation resistance) always a good RX antenna?
5. Are There Any Truly Efficient Multiband 160M-10M or 80M-10M Wire Antennas?
6. Why We Don't Build a 6:1 UNUN for High Power Applications
   
7. Why Do I Need a Kilowatt-Rated BALUN If I Only Run 100 Watts?
   
8. Common Issues and Their Solutions
   
9. Why a 600-Ohm Open-Wire Doublet with a Z-Match is More Efficient Than a 450-Ohm System with an Asymmetric Tuner
   
10. If You Could Choose Only One QRO Multi-Band Antenna, Which One Would It Be?
    
11. Reducing RF Interference from Solar Panels: How to Mitigate Noise on Your Beam Antenna
    
12. Debunking the Height Myth: Why a 20M Yagi May Not Be Your Best Choice
    
13. What Is the Biggest Effect of a Line Isolator?
    
14. Why Choose a +45 dB Line Isolator? The Benefits Over Standard Chokes
    
15. Why a LineIsolator at the Transceiver and a Balun on a Dipole Are Always Necessary
    

EndFed Antennas Installation guides

1. EFOC29 Antenna Installation Guide
   
2. EFOC17 Antenna Installation Guide
   
3. EFOC8 Antenna Installation Guide
   
4. Optimizing the EFOC29 for 160m-10m Band Operation with additional Radials

UNUN and BALUN Installation guides

1. General UNUN user installation guide & safety instructions
2. General BALUN user installation guide & safety instructions
3. General LINE ISOLATORS user installation guide & safety instructions
4. General ANTENNA TUNER BALUN user installation guide & safety instructions

PCB Products Installation guides

1. 2023-P-811 PowerPole Power HAT for Raspberry Pi  Installation Guide