On Thu, 19 Mar 2015 16:20:58 +0000, Ian Jackson
wrote:

In message , Don Pearce
writes
On Thu, 19 Mar 2015 13:58:37 +0000, Ian Jackson
wrote:

In message , Phil
Allison writes
Brian Gaff wrote:


I think the worst case I saw was a Pioneer receiver which kept calling a
ferrite rod am aerial a Loopstick,

** Correct name, in my experience.

A "loopstick" is a ferrite rod antenna that replaces the old loop antenna.

Indeed. It's what the Americans have always called a ferrite rod aerial
(well, at least since the 1950s).



That name never happened in the UK - or if it did, I never heard of
it. It doesn't make much sense either - it can't be a loop and a
stick.

On the contrary, it IS fairly logical. It a loop (or, more accurately,
lots of loops) of wire, wound on a ferrite stick.

A loop is a very specific type of antenna.

And so is a 'loopstick'.

Yes, it's simply a loop antenna (of many turns) wound onto a stick of
ferrite, hence the name, 'Loopstick'. What the brits called a ferrite
rod (aerial/antenna) back in the late 50s/early 60s, the yanks called
(exactly the same thing) a 'Loopstick' The yank name has been around
for just as long as the british name.


I know about using a loop AND a stick to resolve the two possible
directions from a loop DF antenna, but that isn't what this is about.


The rod in this case simply being a short electric field detector to
resolve which of the two possible directions that a loop antenna would
respond to on its own (normally using the null for most accurate
directional information). I think the loop would be used on its own to
get a bearing/reverse bearing and the 'stick' antenna would be
combined to determine from which of the two bearings the signal was
originating from.

Not all of what some Brits call 'crass Americanisms' are completely
crass. Some names give a fairly good description of what a device does.
For example, in the world of cable TV, a constant impedance, variable RF
attenuator acquired the name of 'varilosser'. On the other hand, a
'toob' could be anything!

The constant impedance attenuator used in professional audio mixing
desks are simply called 'faders'.

The 'toob' or "Tube" reference was derived using the same reasoning
behind the everyday name for an incanescent lamp, Light Bulb, on
account of it's resemblence to a 'bulb'. In this case, apart from the
very earliest examples of thermionic vacuum devices, most thermionic
valves used a cylindrical glass envelope, giving them a tube like
shape which the yanks (God Bless 'em) in their rather unsophisticated
way, decided to use in place of the technically more accurate valve
part of the name Thermionic Valve, creating the americanised
expression "Thermionic Vacuum Tube" or simply "Vacuum Tube" (the
corresponding UK abbreviation simply being the word "Valve").

The one exception in UK usage being that "Picture Valve" swiftly got
dropped in favour of "Picture Tube" or, more commonly and simply,
"Tube". The yanks used an even more descriptive name for a CRT,
calling it "The Boob Tube" when it was used in a TV set. :-)
--
J B Good

On Thu, 19 Mar 2015 18:13:36 +0000, Johny B Good
wrote:


The rod in this case simply being a short electric field detector to
resolve which of the two possible directions that a loop antenna would
respond to on its own (normally using the null for most accurate
directional information). I think the loop would be used on its own to
get a bearing/reverse bearing and the 'stick' antenna would be
combined to determine from which of the two bearings the signal was
originating from.

In direction finding you start with the loop antenna only. You find
the signal, then turn the antenna until it disappears. The direction
of the antenna axis is now at 0 degrees to the target. The minimum
will be found again with the loop turned 180 degrees. You use a
minimum because it is far sharper in angle than the maximum. Then you
couple in the stick antenna and search this time for a maximum. This
will only happen in one direction, and it will identify which of the
two possibles is the right one.

An alternative form of direction finder uses two loop antennas mounted
at right angles. The signals from these are used to drive the x and y
axes of a scope. The phase and amplitude are such that the bearing of
the source is shown as a line across the screen. Calibrate it in
degrees and the job is done. You still need to resolve the 0/180
degree problem.

d