Radio

Amateur
Radio

HF QRP operation —
Low-power but still long-distance communication on the HF bands, using CW (Morse Code)

SMK 40m QRP CW amateur radio transceiver. Circuit board holding many SMT (surface-mount technology) components.

Surface-mount technology (SMT) construction — the NC2030 QRP HF transceiver

Morse Code

Build a QRP RF 50Ω Load and Power Meter

Rhombic antennas — Classic designs for UHF & microwave

Small HF antennas — Shortened doublet designs for 10.1 and 14 MHz

J-pole antennas, also known as
End-fed half-wave Zepps

Modifications for the Icom IC2-SAT and IC-229H 144-148 MHz FM transceivers —
Many years ago, I posted a few articles to USENET on how to modify the IC2-SAT and IC-229H for wide-band receive. And no, I don't know any more about the topic now than I did back then! But here is what little I do have on mods for these two Icom transceivers:

IC2-SAT modification, Part 1 — This describes measurements of the sensitivity of the Icom IC2-SAT across the newly expanded receive range.
IC2-SAT modification, Part 2 — This describes the details of the modification itself.
IC-229 modification — This describes how to modify the Icom IC-229, and tells what to expect for results, including aviation band sensitivity.

Modifications for the Icom IC-3220 VHF/UHF FM transceiver

QST archive 1915-present!
The American Radio Relay League has made an archive of most articles from QST magazine available to members! http://www.arrl.org/members-only/qqnsearch.html

World Radio magazine went from print to on-line only as it was absorbed by CQ magazine in 2009, back issues of World Radio are available on line.

Service manual archives:

Repeater directory —
http://www.artscipub.com/repeaters/

Grid Square Maps —
http://www.vhfdx.net/callbook/gmap.php

Construction
and
Repair

Repairing a Tektronix 2445A oscilloscope

How to build your own oscilloscope probes

General construction / modification / repair references, plus parts vendors

Other technical topics — construction and repair

Radio Antenna Engineering —
Edmund Laport's textbook is now available for free in electronic form: http://snulbug.mtview.ca.us/books/RadioAntennaEngineering/

Surface-mount technology (SMT) size standards: http://en.wikipedia.org/wiki/Surface-mount_technology