High-gain 435 MHz UHF collinear antenna using three 5/8-wave vertical sections with inductive phasing. Provides ~6 dB omnidirectional gain and low-angle radiation for repeater, base, and long-range 70 cm band operation.
HF
The HF category brings together all content related to high‑frequency bands, from 160 m through 10 m, with emphasis on practical antennas, propagation, and station hardware. Here you will find compact 40 m verticals, multiband wire antennas, HF QRP transmitters, SDR transceivers, and accessories designed for real‑world home and portable operation. Articles often include measured SWR curves, on‑air reports, and build photos so you can understand how a design will behave before you start cutting wire.
There is a strong focus on getting HF on the air from small Indian plots, apartments, and field locations without sacrificing too much performance. Whether you are preparing for your first HF QSO, improving your 40 m NVIS coverage, or chasing DX on higher bands during good conditions, this section provides tested ideas to upgrade your HF station step by step
Housing the LARCSet: A Community-Designed 3D-Printed Enclosure
Ready to move your LARCSet off the workbench? Discover this community-driven 3D-printed enclosure project featuring STL files from Peter Marks and builds by VE3WMB.
20–40–80 Meter Loaded Multiband HF Dipole Antenna
Operating on 80m, 40m, and 20m from a small backyard is no longer a challenge. Learn how to build a compact, loaded multiband HF dipole that uses precision-placed coils instead of traps. This high-efficiency design offers resonant performance on three major bands using a single 1:1 balun
4:1 UN-UN Transformer for End-Fed Antennas
Build a 4:1 un-un impedance transformer to match end-fed wire antennas to 50 Ω coax. Ideal for long-wire, vertical, and off-center-fed antennas, improving SWR and RF transfer in multiband HF installations.
9:1 UN-UN Long Wire Transformer for HF Antennas
This article explains the construction, operation, and real-world usage of a 9:1 impedance transformer (UN-UN) for long wire and random wire antennas, making it ideal for SWL listeners and amateur radio operators.
W5GI Multiband Collinear Antenna: A Proven HF All-Band Wire Antenna
The W5GI multiband collinear antenna combines wire radiators and coaxial phasing sections to deliver reliable HF coverage from 80–6 m. A tuner-friendly alternative to the G5RV with strong multiband performance and efficient radiation for practical ham radio installations
sBitx v3: The Linux SDR That Refuses to Be Boring
Explore the sBitx v3 — an open-source Linux SDR transceiver merging computer and HF radio, enabling portable digital operation without a laptop
RW4HFN Balcony Antenna for the 20-Meter Band
Discover the RW4HFN balcony antenna design for the 20-meter amateur radio band—ideal for limited spaces. Includes schematic, dimensions, and inductance values
RA9SUS Simple Loop Antenna covering 14–30 MHz
The RA9SUS simple loop is a compact HF antenna covering 14–30 MHz using a 4.7 m rectangular loop and variable capacitor tuning. Ideal for balconies and small spaces, it enables efficient multiband operation without large wire antennas or ground systems
ZBitx: The Pocket SDR That’s Redefining Portable QRP
ZBITX is an ultra-portable 5 W all-band HF SDR transceiver with built-in FT8, CW, and digital modes powered by Raspberry Pi. Pocket-sized QRP radio for POTA/SOTA field operation without a laptop.