R-1449/WLR6(V) VLF Receiver

Front picture

Any information at all that can be provided about this receiver would be deeply appreciated. A schematic would be great, a complete manual would be divine, but even lesser info would be welcome. For example, what's the FDD mode on this receiver used for?

Cover Label

Cover and Label

Right Side Left Side

Right and Left Sides

Left Open IF

Loose Module Some modules pivot out for interior access or removal. 2 MHz crystal filters visible on IF module.

Top Top

Rear Rear Panel

Block Diagram Module Wiring Diagram

Of the two R-1449's I acquired, the A10 power supply module was defective on one, and missing on the other. I've heard of other R-1449 receivers missing the A10 module, so suspect that's a weak part of the design. I've traced out the schematic of the A10 module and associated chassis mounted +12 V pass transistor.
A10 Power Regulator Module Schematic

Below is the schematic and photos of the replacement module I built. The circuit was simplified by using a 7912 negative 12 V voltage regulator IC. Copper tape was placed on the board to act as a heat sink. To use the chassis mounted pass transistor, and so that the original or replacement board could be used, I stuck closely to the original circuit for the +12 V side.
Replacement Power Regulator Module Schematic

Replacement PS Front Replacement PS Rear

For information on the related R-1451/WLR6 0.5 - 32 MHz receiver, visit the Rovero Research website.

For information on the Watkins-Johnson 357 VLF receiver, which is said to be closely related to the R-1449, see the Premium Radios website and follow the links to Reference, then Complete Manuals, then Watkins-Johnson 357 (VLF).


Send E-mail

Copyright © 2003-2004 John Kolb Last revised May 7, 2004