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Site Created by:

Chuck Rippel

Copyright: 1996, 1997, 1998, 1999, 2000, 2001, 2002 

See our copyright page for full information

The R390A/URR

Ultimate Performance, General Coverage AM & CW Receiver

Last Site Update: 12/24/2001

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Technical Resource Directory

Find the troubleshooting help, alignment procedure, parts resource or restoration tip here. This section is updated as new material arrives so check back often. Useful contributions are always welcome and will be posted with proper credit.

Quick Reference:    R390A Compendium of Common Problems  (Your Contributions)  (Updated 07/01/00)  (A Printable Page !)

Aligning the COSMOS PTO     (New 07/01/00)    A Printable Page

The Tracking IF System: Theory and Troubleshooting    (New 12/11/99))

Complete listing of Problem Capacitors            (New 9/22/99))

Alternate methods to properly feed the R390A balanced antenna input    (New 6/6/99))    A Printable Page !

Get the Best Audio Reproduction Possible from your R390A !      (New 6/6/99))    A Printable Page !

 Measuring Receiver Sensitivity   (New 9/23/98)    A Printable Page !

Cosmos PTO Setup and Alignment by John Harvie (New 10/21/98)  A Printable Page !

Replacing C-549 and C-553   (New 9/23/98)    A Printable Page !

Converting the R390A Power Supply to Solid State (New 9/12/98)     A Printable Page !

Rebuilding filter capacitors C603 & C606 (New 9/7/98)

IF Deck & Mechanical Filter Alignment

R390A PTO's & Correcting Certain Instability Problems

Setting the IF Gain for Maximum Performance

Testing RF/IF Deck Noise Power

R390A Field Changes     (An Original Document)

List of Official Government R390A Modifications   (An Original Document)

Information on the R390A Video - Do it all yourself

R390A Tube Complement (New 9/7/98)    A Printable Page !

IERC Heat Shields (New 9/7/98)    A Printable Page !