Valiant Mods
W8TOW describes in detail how to improve the audio on the Johnson Viking Valiant transmitter. http://www.msu.edu/~wb9tow/mods.htm
Eico 730 Modulator
Improvements made to a boatanchor classic. http://www.amwindow.org/tech/htm/eico730.htm
FT-101 Mods
Yaesu-Musen Company FT-101 series audio modifications for improving fidelity on the air. http://www.amwindow.org/tech/htm/ft101.htm
WA2ISE Old Radios
Information, pictures and schematics. History of the All-American 5. Includes modifications, and sub-miniature tube info. http://www.geocities.com/CapeCanaveral/9178/
Heathkit HW-16 Modifications
WA3REY presents a number of transmit and receive mods. http://www.wa3rey.com/hw16.htm
K5DKZ
6146 conversion kit for the Drake T4X (instead of two 6JB6 finals). He also offers other kits and repair tips for radios and amplifiers. http://www.qsl.net/k5dkz/
Radio Modification files
Files of mods arranged by brand and model, plus a few Heath. http://qrz.com/download/main/mods.html
Hot rodding AA5 radios
How to make vast improvements in the typical "All American Five" tube receiver. http://www.geocities.com/CapeCanaveral/9178/radios/12ba7.html
6146 Diagrams FTP
Download GIF and PDF diagrams here for the modification of power amplifier stages from Sweep tubes to 6146es. ftp://bama.sbc.edu/downloads/drake/6146conv/
AM Rig Modifications
From The AM Window folks. Excellent source of information. http://amwindow.org/tech/htm/mods.htm
E.F. Johnson Co. Ranger Mods
Tim Smith, WA1HLR shows his audio improvements for this rig. http://amwindow.org/tech/htm/rangtron.htm
Southeast Iowa Technical Society
Articles on modifying the Motorola Mitrek for the ham bands. http://www.seits.org/repeater/mitrek/mitrek.htm