[Milsurplus] ADF vs. HFDF

[Richard Brunner]

William Donzelli wrote:
..... Well, yes, they were slow as cement, but the Navy did have 
shorebased HFDF
> sets in the 1930s for intercept work. The Army also had some big HFDF sets mid-war, like the SCR-291/502. Anyone
> know if these worked with the Navy, or were they only used for land based
> intecepts?

The navy and army undoubtedly had HFDF (high-frequency direction 
finding) stations from the 1930's on, but they were manual.
The U-Boat transmissions using Kurier-Signal were very short, 337 
milliseconds maximum, and manual DF'ing wouldn't have a ghost of a 
chance of finding them.  Huff-Duff was direction finding using two 
antennas to two receivers feeding a scope to give an instantaneous 
vector, and would indeed catch the Kurier transmissions.  The idea was 
first developed in 1926 by R. A. Watson-Watt to localize thunderstorms, 
but apparently wasn't used by the military until late in WWII, and named 
Huff-Duff.

Referenz:  "Funkpeilung als alliierte Waffe gegen deutsche U-Boote 
1939-1945."  Arthur O. Bauer, 1997 (in German)

Richard Brunner, AA1P