Autumn Sparks: Baluns, Myths, and Mailbox Madness
The trees are shedding their leaves, field days are winding down, and over here the soldering iron is heating up again. Less outdoor noise means more writing — and our mailbox is buzzing. Many of your recent questions sparked full-blown articles, and some of them turned into myth-busting deep dives below.
Baluns in a Nutshell
A concise look at current vs voltage types — when to use which, and why the right choke placement matters more than the ferrite mix itself.
🔗 https://shop.rf.guru/pages/baluns-in-a-nutshell
How Much Choking Do You Really Need for RX and TX?
Forget the one-number dB myth. Here’s how to match common-mode impedance to your band and power level — without over-engineering it.
🔗 https://shop.rf.guru/pages/how-much-choking-do-you-really-need-for-rx-and-tx
Why “Common-Mode” Is the Most Abused Term in Ham Radio
Engineers wince when this term gets tossed around. Let’s clean up the vocabulary — and your signal path.
🔗 https://shop.rf.guru/pages/why-common-mode-is-the-most-abused-term-in-ham-radio
When Open-Wire Feedline Starts to Radiate
That magic balanced line isn’t always innocent — we show when and why it radiates, and how to fix it.
🔗 https://shop.rf.guru/pages/when-open-wire-feedline-starts-to-radiate
Lowering SWR on a Dipole or Inverted-V by Making It Asymmetric
A touch of asymmetry can tame high SWR. Here’s the geometry trick that every tuner secretly loves.
🔗 https://shop.rf.guru/pages/lowering-swr-on-a-dipole-or-inverted-v-by-making-it-asymmetric
Stray Return Currents on the Coax Braid Can Accelerate Connector Corrosion
It’s not just electrochemistry — it’s RF. See how unseen common-mode current slowly eats your hardware.
🔗 https://shop.rf.guru/pages/stray-return-currents-on-the-coax-braid-can-accelerate-connector-corrosion
Drop SWR, Keep Return-Loss and Insertion-Loss
A fresh take on SWR obsession: lower numbers don’t always mean lower loss.
🔗 https://shop.rf.guru/pages/drop-swr-keep-return-loss-and-insertion-loss
Licenses, Loopholes, and the Myth of “Real” Operators
Paper doesn’t make performance. A reflection on skill, ego, and the myth of the “full” license.
🔗 https://shop.rf.guru/pages/licenses-loopholes-and-the-myth-of-real-operators
Carbon Radiators – Miracle Antenna or Marketing Smoke?
If carbon really radiated well, your pencil would make a fine 20 m dipole. We’ll test the claims soon.
🔗 https://shop.rf.guru/pages/carbon-radiators-miracle-antenna-or-marketing-smoke
The 50-Ohm Myth – What Really Matters in Ladder-Line Baluns
Why chasing perfect 50 Ω can backfire, and how balanced systems behave in the real world.
🔗 https://shop.rf.guru/pages/the-50-ohm-myth-what-really-matters-in-ladder-line-baluns
Balanced vs Unbalanced Tuners
There’s no one-size-fits-all. Learn what “balanced” really means inside your tuner.
🔗 https://shop.rf.guru/pages/balanced-vs-unbalanced-tuners
Faraday Strips – 23 % of Nothing Is Still Nothing
The viral “miracle ground” myth gets a reality check with math and measurements.
🔗 https://shop.rf.guru/pages/faraday-strips-23-of-nothing-is-still-nothing
Why Most SWR Meters Don’t Really Measure SWR
Because what they show isn’t what you think it is. Here’s the calibration story behind the needle.
🔗 https://shop.rf.guru/pages/why-most-swr-meters-don-t-really-measure-swr
How Much Choking Do You Really Need for RX and TX?
(Yes, it’s that important.) A practical follow-up on measured common-mode impedance per band.
🔗 https://shop.rf.guru/pages/how-much-choking-do-you-really-need-for-rx-and-tx
Kurt Speaks Out – Updated Technical Notes and Modern Errata
Classic truths revisited: which 1980s “laws” still hold, and which need an update for today’s rigs.
🔗 https://shop.rf.guru/pages/kurt-speaks-out-updated-technical-notes-and-modern-errata
Reflections Revisited – What’s Still True and What’s Been Refined Since W2DU
Half a century later, the reflection debate isn’t over. Here’s where measurement beats memory.
🔗 https://shop.rf.guru/pages/reflections-revisited-what-s-still-true-and-what-s-been-refined-since-w2du
Thévenin Equivalents in Receive Systems
Why Thévenin’s 1883 insight still underpins every receiver front end today.
🔗 https://shop.rf.guru/pages/thevenin-equivalents-in-receive-systems
Johnson Noise & Thermal Noise – What Is It?
The random hiss that defines the ultimate sensitivity of your receiver.
🔗 https://shop.rf.guru/pages/johnson-noise-thermal-noise-what-is-it
The New Ham Species – Homo Ignoramicus Technicus
A gentle roast of the modern ham who fears ferrites and worships SWR dips.
🔗 https://shop.rf.guru/pages/the-new-ham-species-homo-ignoramicus-technicus
📻 The Gospel According to Professor Wattson
The fictional professor returns — this time preaching VSWR salvation to the un-tuned masses.
🔗 https://shop.rf.guru/pages/📻-the-gospel-according-to-professor-wattson
Thanks for reading Issue #9 of the RF.Guru Lab Newsletter.
Keep the questions coming — they’re fueling the next batch of experiments and myth demolitions.
Stay warm, stay curious, and as always — let physics do the talking.
73,
Joeri – ON6URE
Founder – RF.Guru
https://rf.guru/