[Milsurplus] ADF vs. HFDF

[Mike Morrow]

George wrote:

>I know that the Bendix and AN/xxx systems were used in the 
>bombers for navigation, but has anyone ever heard of using
>one to track submarines?

Even had the boats emitted continuous signals for than a fraction of a second in length (they didn't), none of the airborne DF sets were usable on HF bands for direction finding.  The manuals say that even the MN-28LB or MN-28Y manual DF sets, which had a third band covering either 2.9 to 6.0 or 3.7 to 7.0 mc, were not usable for DF'ing on that third band.

The other ADF sets extended no higher than 1.5 or 1.75 mc, well below the frequencies used by the boats.

I think the 1970s vintage AN/ARN-89 was one of the few airborne ADF sets that went above 1.75 mc with DF function.  It went to 3.0 mc.

Cold War US nuclear submarines used (in extremely unusual circumstances) HF data-burst transmission somewhat akin to the WWII German HF "Kurier" code-burst system.

73,
Mike / KK5F