Why We Started RF.Guru
It didn’t start with a business plan. It started with frustration.
After years of struggling with antennas that didn’t survive storms, baluns that filled with water, and mysterious "wonder antennas" that defied both logic and datasheets, we reached a breaking point. The tipping moment came when a trusted Wellbrook loop—once a prized piece of the shack—failed due to water ingress. That was the last straw.
We had seen too many so-called verticals fold like spaghetti in the wind, too many preamps built around transistors older than we are, and too many UNUNs filled with the wrong ferrite—if any at all. Documentation was often an afterthought, assuming it existed. Support? Nonexistent.
That’s when the decision was made: we’ll build everything ourselves. Not just better, but right. Using the correct materials, documenting thoroughly, and designing with the actual user in mind—ourselves included.
At first, this was a personal mission: to fix our own receiving setup, to build an antenna that wouldn’t lie about what it was, and to stop wasting money on compromised gear. But it quickly became clear we weren’t the only ones tired of the mediocrity.
So RF.Guru was born. Not to be the biggest. Not to be the cheapest. But to be the most honest and technically sound supplier of high-performance antennas, baluns, and RF solutions—especially for those who care about signal quality, not just the sticker on the box.
We don’t believe in “magic" antennas. We believe in physics, documentation, and support. And we’re building the tools we wished we had from the beginning.
This is RF.Guru. It started with one broken antenna—and a refusal to buy junk ever again.
About the Founder
RF.Guru was founded by Joeri van Dooren, callsign ON6URE. A lifelong radio amateur, RF engineer, and electronics enthusiast, Joeri brings a unique blend of hands-on experience and technical precision to every product. His background in both analog and digital design, combined with a relentless curiosity and high standards, drives the philosophy behind RF.Guru.
Over the years, Joeri became known in the ham radio community for his deep knowledge of antennas, his critical eye for quality, and his ability to turn theory into practical, working designs. He believes in transparency, sharing knowledge, and building gear that he would proudly use himself—because he does.
Jonas van Dooren
The mechanical genius behind the operation is Jonas van Dooren, Joeri's son. Without Jonas, things would simply look boring. His expertise in mechanical engineering, materials, and 3D design transforms functional products into robust, reliable, and aesthetically refined tools. He is the reason our products don’t just perform well, but survive real-world abuse.
Some might say we overdesign things. That’s fine by us. We like our antennas to be hurricane-proof. When we state that you don’t need to guy them, you really don’t. Design decisions are made based on quality and durability—never on cost cutting. Jonas ensures that every component reflects that philosophy.
Jonathan van Dooren
Behind the scenes, Jonathan van Dooren—Joeri’s cousin and business partner—keeps the operation running smoothly. He oversees logistics, supplier relations, administration, and bookkeeping. From managing inventory to tracking complex shipments and maintaining supplier contracts, Jonathan is the organizational backbone of RF.Guru.
His structured approach ensures orders go out on time, raw materials arrive when needed, and no detail is overlooked. While others focus on RF performance or mechanical design, Jonathan makes sure the business itself performs just as reliably. Thanks to him, RF.Guru operates with the efficiency and stability you'd expect from a much larger company.
What started in a home workshop has since grown into a recognized name among serious radio operators. But the mission hasn’t changed: make better tools for better signals, and never settle for mediocrity.
What We've Built (So Far)
Launched in April 2022, RF.Guru has already introduced a comprehensive lineup of receive and transmit gear, baluns, and accessories:
RX Antennas:
- EchoTracer: A compact active E-field probe optimized for HF reception with excellent CMRR and broad coverage.
- OctaLoop: A broadband active loop antenna for general HF reception, offering low noise and good directionality.
- TerraBooster: A shielded loop-on-ground (LoG) RX antenna available in Mini, Standard, and Maxi variants, engineered for low noise pickup and high urban survivability.
- SkyTracer: A capacitive-loaded dipole-style RX antenna optimized for the upper HF bands (30–10m).
- VerticalVortex: A high-performance vertical E-field probe for low-band (160–40m) reception.
- PulseRoot: An active Beverage-on-Ground (BoG) style antenna with automatic termination switching for directional diversity.
TX Antennas:
- The EFOC multiband series (no "cat in a bag" 4010 or 8010 gimmicks)
- Dual-band EFHWs with optimized transformation ratios
- EFHWs with 70:1, 68:1, 56:1, and 49:1 transformers, all QRO rated from 2 kW to 4 kW PEP
- Solid V dipoles
- IronWave6: a 4:1 UNUN-fed vertical covering 40 to 10 meters
- VertX: multi-element 1/4 wave vertical for 20 to 10 meters
- Solid DeltaLoop series
- 600-ohm open wire fed doublets
- Monoband Inverted V antennas with either openwire or coax feed
Baluns and Matching:
- Wideband baluns for open wire
- Antenna tuner balun
- Complete line of UNUNs: 4:1, 1:2, 9:1 available in single or dual-core variants up to 3.4 kW PEP
Electronics:
- Analog hotspot and transceiver, including a version with built-in 4G
- LoRa tracker for direct car battery hookup
- 2 ARDF fox transmitters (2m and 80m)
- uPaddle: a capacitive iambic keyer
- Repeater modules
- 75-ohm GPS antenna with multiple outputs
RX Enhancement and Phasing Systems:
- PolarFLIP: A precision phasing controller that flips polarity between LHCP and RHCP, supporting both circular and elliptical polarization modes. Ideal for diversity setups and space-limited arrays. All outputs are available in parallel for SDR and multi-operator use.
- EchoTriad: A 3-element equilateral phased array controller for EchoTracers or VerticalVortex antennas. Optimized for low-angle DX, it provides clean directionality and deep rear nulls. All azimuth outputs are simultaneously accessible.
- QuadraTUS: A 4-element phased FourSquare-style array controller for VerticalVortex on 160 and 80 meters. Engineered for ultra-low-noise reception, high RDF, and reliable directional separation. Fully multi-operator ready with all outputs live and in phase coherence.
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SignalHUB 8: An 8-port remote-controlled receive switch with integrated per-band/antenna attenuator, managed via LoRa. Built for SDR platforms and multi-operator environments.
More Than Just Products
RF.Guru also invests heavily in education and clarity. Our Knowledge Base features over 100 detailed publications, spanning 20+ categories such as EFHW theory, baluns, RX system design, and more. From practical how-to guides to deep technical breakdowns, it reflects our belief that good engineering starts with understanding.
In ham radio, many things are explained half-heartedly, and technical terms are often thrown around without context. That's why we put effort into dotting every i: explaining not only why things work, but also why some methods don’t—and what the better alternatives are. We take time to debunk myths and expose poor design practices, not to point fingers but to elevate the entire community.
Our products are a direct result of this philosophy. Each antenna, balun, and accessory is designed with durability and performance in mind, backed by thorough documentation and support. We believe that by combining robust engineering with comprehensive education, we can elevate the standards of amateur radio equipment and practice.