Low-Loss Feedline on a Budget: Building 450 to 600 Ohm DIY Ladder Line

DIY Ladder Line for the HF Ham A complete technical guide to building, routing, and using open-wire balanced feedline at your station

Ladder line is a type of feedline made of two parallel wires held apart by small spacers at regular intervals. When you look at it from the side it looks exactly like a ladder — hence the name. The spacers keep the wires a fixed distance apart all the way from the antenna down to your radio room.

Unlike coax cable, which has a center conductor buried inside solid plastic and covered by a metal braid, ladder line is open to the air. This is not a flaw. It is actually its biggest strength. Air is one of the best insulators there is, and it does not eat up your signal the way solid plastic does.

The two wires carry equal and opposite signals. Because they are close together and balanced, the fields from each wire mostly cancel each other out. Very little energy radiates from the feedline itself. This means nearly all your transmitter power reaches the antenna, where it belongs.

Low-Loss Feedline on a Budget: Building 450 to 600 Ohm DIY Ladder Line from Common Materials:

3 x 5/8 Collinear antenna for 435 MHz UHF Band

For UHF repeater systems operating around 435 MHz, antenna efficiency and gain are critical. Simple vertical antennas often do not provide sufficient performance, especially when wide coverage and reliable signal strength are required. To address this need, a UHF collinear antenna design adapted from the well-known Diamond BC-200 has been developed and documented by Kostadin Evstatiev (LZ1DJ).

This 3 x 5/8 Collinea antenna is intended specifically for the 420–440 MHz band and provides high gain without requiring post-installation tuning when constructed accurately.

3 x 5/8 Collinear antenna for 435 MHz UHF Band

DIY Antennas for LoRa and Meshtastic: A Complete Guide to 433, 868, and 915 MHz

LoRa radios offer incredible long-range, low-bandwidth communication—but only if your antenna is up to the task. A poor antenna can limit you to a few hundred meters, while a well-built DIY design can push past 20 km. The best part? You can build proven, high-performance antennas for just a few dollars.

This guide covers everything you need to build your own LoRa antennas for LoRa and Meshtastic 433 MHz (Europe/Asia/amateur radio), 868 MHz (EU), and 915 MHz (North America/Australia). You’ll find exact dimensions, construction tips, band-specific trade-offs, and real-world performance comparisons.

Stock antennas that ship with LoRa modules, Meshtastic nodes, and Helium Hotspots are typically tuned for minimal cost rather than maximum performance. They’re often mismatched to your specific frequency, use cheap materials, and have poorly characterized radiation patterns.

DIY Antennas for LoRa and Meshtastic: A Complete Guide to 433, 868, and 915 MHz: 

OXO QRP HF Transmitter

The OXO QRP HF transmitter is a simple, low-power CW (continuous wave) transmitter designed by George Burt, GM3OXX. It is a single-band transmitter that can be built to operate on any of the amateur radio bands from 160 to 20 meters. The transmitter is built around a few standard transistors and a crystal oscillator. It is an elementary circuit to build, and can be assembled from a kit or from scratch.

Fig: OXO QRP HF Transmitter

The OXO transmitter is a QRP HF transmitter, which means that it produces a very low output power. This makes it ideal for making short-range contacts with other amateur radio operators. The OXO transmitter can also be used for experimentation and learning about radio electronics.

OXO QRP HF Transmitter