R-390A
Overhaul Discussion
Servicing R 390As at Aesop's shop has averaged 50 hours to clean, troubleshoot, fix, and align, by an experienced tech with tools, test equipment and a stock of replacement parts from cannibalized receivers. In addition, it takes about a month of "burn in" to stabilize components for proper final alignment, as tubes’ heat drives the moisture out of coil forms, and the high voltages reform capacitors.. At current shop rates and parts prices, a "restoration" to stock performance can easily cost over $1000. This does not include the optional extra modifications included in several dozen K1QAR "overhauled" receivers : Treetop product detector, 6:1 BFO reduction drive, oscillators’ filaments current regulator, solid state power supply, soft start thermistors, heavy duty covers with feet, refinished panel, etc). K1QAR does service on sent in R 390As, and can provide an estimate based on your receiver's condition and desired optional mods. As a low cost alternative, one can bring their R 390A (or KWM-2) to the free clinics at some New England ham fests, ARRL Conventions the Near-Fest, or the Vintage Electronics expos. in New Hampshire and Massachusetts. Alignment and troubleshooting are done free (first come, first served). The advantage of the clinic at a ham fest is that needed replacement components, such as connectors, resistors, filters, tubes, etc. for repairs are usually available on the spot for low prices.
73, Ted Robinson, K1QAR