Cover and Label
Right and Left Sides
Some modules pivot out for interior access or removal. 2 MHz crystal filters
visible on IF module.
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
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).
Copyright © 2003-2004 John Kolb Last revised May 7, 2004