National Radio Company's AN/FRR-24 HF Receiver Tuner Module (Model: Amplifier-Converter AM-450B/FRR-24) --- The Ultimate Big-Iron Receiver ---
---left front---	---right front---
---top view---	---bottom view---
---close up of sealed 5-gang main tuning capacitor---	---close up of fine tuning scale in kilocycles---

The 1950s National AM-450B/FRR-24 is the tuner module of what is perhaps the most expensive, elaborate HF receiver ever manufactured in the United States. A complete receiver equipped for triple diversity monitoring--with all four RF modules for the full HF range of 2 to 32 MHz--contains a total of 420 vacuum tubes, weighs 3,121 pounds in four six-foot rack cabinets, and sold for $60,000+ in 1947 dollars (or $581,000 adjusted for CPI inflation). It truly is a "Duesenberg" of radios and represents the very best of National Company's engineering talent.

I have only one of the 9-tube, 2-4 MHz tuner modules, which includes 3 RF stages and separate mixer and oscillator tubes providing a 1750 kHz IF output for this double-conversion receiver. I would like to set it up for 80-meter operation with a homebrew power supply and IF amplifier/detector. I am indebted to Nick England, K4NYW, for schematics and other documents and especially his expertise. If you can contribute any information to Nick regarding its development and historical use, I am sure he would love to hear from you. His website, which contains a treasure of photos and information about this receiver and other military models of interest to Nick, has the following URL:

http://www.navy-radio.com/rcvrs/frr24.htm

--- 1953 National Radio Co. Ad ---

Also see:

A Brief History of the National Radio Company by John J. Nagle, K4KJ

Index of webpage links for National Radio Company

The National Radio Company by OLDRADIOS.CO.NZ

National R1230/FLR Wide Band Receiver

e m a i l

return to KK6HY home page

Copyright © 2009 H.A. Layer, all rights reserved