[Milsurplus] LO radiation

[J. Forster]

b. smith wrote:

> With a weak signal it is much easier and faster to obtain an aural null.
> If the operator were  using a direct driven  manual antenna that utilized an
> "Arm Strong Rotator"(steering wheel) without gears and cables, the null could
> be
> obtained in seconds.
> Granted the "weak signal" correct bearing would be broad , say 20 to thirty
> degress but close enough to get you started in the correct direction and to
> get you in visual range. Signal varying with the square of the distance. If
> the signal strength  picked up the operator had the correct bearing, signal
> weakens then reverse direction.
> Starting with an assumed over the horizon signal(it must be over the horizon
> or you would not be going through this DF drill) Each participant could see
> the tops of the vessel approximately  7 or 8 miles ( and I will not quibble
> over the difference between the statue mile and a nautical mile which is
> approx 800 feet) So the idea is to get within 14 to 16 miles  for visual
> sighting on a smooth sea and no restrictions to visibility. Then the fun
> begins.
>
> breck k4che

Compare the DF as a search technique to a relatively early radar, the ASB-5. (I
choose this one, because I happen to collect it) It operates between 400 and 600
MHz and can scan out to 70 miles on each side of the plane (if the manual is to
be believed). That means at extreme range it can search a 140 mi wide path.
That's a whole lot more than a DF system seems capable of, and this is a very
early radar.

AFAIK, the only down side of using such a system is that it's an active search,
rather than a passive one.

-John

BTW, does anyone have the manuals for an ASB-5 that could be copied, scanned, or
bought?  I'd really appreciate it.