Learn how to build a simple high-gain collinear antenna using coaxial cable for VHF/UHF amateur radio. Low-cost DIY design with improved omnidirectional coverage and better range than a standard vertical
DIY
“DIY” on DXR Electronics Bits is where practical ham radio projects come to life. Here you’ll find buildable circuits, antennas, receivers, preamps, audio tools, and experimental rigs designed for real‑world shack and field use. From compact HF antennas for small spaces to regenerative receivers, QRP transmitters, and uBITX add‑ons, each article focuses on parts you can actually source and solder on the bench.
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
Building a Andy 2E1TAP’s Shortened 40-Meter Delta Loop
Full-size Delta Loops for the 40-meter band normally require around 42 meters of wire—often impossible for operators with limited space. To overcome this challenge, Andy (2E1TAP) documented his attempt at constructing a space-efficient, shortened 40-meter Delta Loop.
Shortened Vertical Antenna for the 80-Meter Band (UR0GT Design)
Compact 4 m shortened vertical antenna for the 80 m band using a 64 µH loading coil and LC base matching network. UR0GT design enables efficient 3.65 MHz operation in small spaces with full-size radial system for strong HF performance.
Dual-Band RW4HFN Antenna for 145/430 MHz bands
Compact dual-band RW4HFN antenna covering 145 MHz (2 m) and 430 MHz (70 cm) with a center-fed element and integrated matching section. Single-feed 50 Ω coax design provides versatile VHF/UHF operation for base, portable, and repeater use.
A Broadband Butterfly Antenna for VHF and UHF
The broadband butterfly (bi-square) antenna uses two connected square loops to deliver stable 50–75 Ω impedance, low noise, and several dB gain over a dipole across VHF/UHF bands. Simple bidirectional design requires no tuning and scales easily for 144 MHz and 430 MHz operation
DIY Wideband CMC Choke Using Steel Wool and RG-213 – A Simple Common-Mode Filter
Common-mode currents are a well-known enemy of clean RF communication. When RF travels along the outside of your coaxial cable, it causes feedline radiation, noise pickup, RFI in the shack, audio distortion, and unpredictable SWR variations. To solve this, radio amateurs typically install a CMC choke (also called a current balun or common-mode filter) at […]
VHF Radio Receiver Antenna Amplifier Using MAX2633 – Simple Low-Noise RF Preamplifier Design
Build a low-noise VHF RF preamplifier using the MAX2633 MMIC to improve receiver sensitivity and antenna signal strength on 144–148 MHz. Simple biasing and matching provide wideband gain for FM, repeater, and weak-signal reception.
Square Loop Antenna for 144/430 MHz – Complete DIY Dual-Band Build Guide
The dual-band 144/430 MHz Square Loop Antenna is one of the most efficient and compact VHF/UHF antennas that amateur radio operators can build at home. Designed to cover both the 2-meter and 70-centimeter bands, this antenna offers excellent gain, low noise reception, and impressive SWR when constructed correctly.