[Milsurplus] ADF vs. HFDF

[Mike Morrow]

Richard wrote:

>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)

There are excerpts (mostly in German) from this interesting book at:

http://cdv-and-t.org/

There is a link to a 23 page article on the technical details of the HF-DF systems used by the British (FH3 and FH4 sets) that takes you to:

http://www.xs4all.nl/~aobauer/HFDF1998.pdf

If you poke around a bit on the HF-DF topics, you'll even find a picture of the FH4 HFDF set.

As Richard points out, there is very little that aircraft LF/MF ADF sets had in common with shipboard rapid-response HF-DF technology.  The HF-DF system was far far more sophisticated.

73,
Mike / KK5F