The R-390A Frequently Asked Questions Page

Pearls of Wisdom

Wei-Li has been collecting and categorizing the wisdom which flows through the R-390A mailing list for many years. He periodically shares his collection here.

Below are links to the e-mail postings by category.

This document is a compilation of the wisdom shared by members of the online community of R-390A enthusiasts. As such, it is advice to those who endeavor to maintain and restore the R-390A family of receivers.

The information is shared without warranty, expressed or implied. This information is in the public domain and can be freely copied or shared.

Appropriate attribution is appreciated.

AC and Other Line Topics


Audio Deck

Ballast Tube


Dead Units

Dead Unit Inspections


IF Deck

IF Deck Filters


Mods and Field Changes

Painting and Knobs


Panel Meters


Power Supply

R-392 and R-648 Notes

Racks and Cases


Restoration, General

RF Deck, Electrical

RF Deck, Mechanical

Sensitivity Alignment

SSB Conversion

Storage and Shipping

Test Gear

Tubes and Tube Testers

Tube Shields - Heating

R-390 (non -A) and R-391 Notes


  • Wei-i Li

Send Comments to the FAQ-Meister: (root[at]r-390a[dot]net)

Version: 51 - - Last revision: 2021-Nov-15