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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: 05/02/01

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New Additions!

I am always looking for new, accurate and useful information to present.  Click on the titles below to view the latest additions.

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The ``Secret" behind receiver performance:  The Tracking IF stages explained !

Wondering how the R390A tracking IF system works?  Have a gain problem?  Here is am explanation to how the heart of this fine receiver works.  Gain and troubleshooting tips are included.

Converting the R390A Power Supply to Solid-State

How to and discussion on changing the 26Z5W rectifier tubes, V801 and V802 to solid state

New !  9/12/98

Feeding the R390A Antenna Input

Feeding the receiverantenna input through the ``BALANCED input yields the best results.  Here at instructions and pictures of doing it without expensive, hard to find connectors.!

New ! 6/6/99

Get the story behind the R390A with Factory SSB

Thats right !  See an ultra-rare Stewart-Warner R390A equipped with factory installed SSB detection circuitry.  Also included is actual audio from the receiver.

New !  04/301/99

Now Installing Longwave Products Replacement Mechanical Filters

You may have read the recent Electric Radio review on Longwave Products, replacement 6, 2.5 and .5kc Collins mechanical filters for the R390A.  I am now offering their installation as a option in receivers which I am restoring.   Follow the link for more information.

New !  04/15/01

What do I offer?  How to contact me?

Working on your own R390A?  I can help.  Go here to find out how

New ! 9/7/98

Replacing C-549 and C-553

This is a"must do" for any R390A owner.  An explanation of the procedure coupled with hi-resolution pictures helps make it easy.

New !  9/23/98

 

Cosmos PTO Alignment by John Harvie

Cosmos PTO's are often maligned for their end point accuracy.  However, consider that once properly set up, the Cosmos PTO is among the most accurate PTO available for use in the R390A.  Read R390A List member John Harvie's narrative on setting up a Cosmos PTO.

 

New !  10/21/98

Get the Best Audio From Your R390A

Your R390A is capable of excellent audio reproduction.  Here is how to do it.

New !  6/06/99

The R390A Filter Story

The full story on the ``magic" of R390A IF filtering.  Also, Think that Collins mechanical filter the only ones used in an R390A?  This story may just suprise you.  Follow the link for information.

New !  5/01/01

A personal tour.  Have a look at some rare and not so rare radios.

Virtual Shack Tour:  Amateur Radio Station

Virtual Shack Tour:  Receivers

Updated November 27, 2004