As you know I am mad about radios, WW2 airplanes, tanks & subs.

I was thinking about getting a compass so that I could better find my
possition at home. So I did a search on Ebay on Compass. I then came
accoss something that is called a Radio Compass.
EBAY Item number: 6565758752

My guess it that the gauge is telling the pilot his dirrection in the
sky. But why is it called a radio compass?

Is the device putting out a signal? And is the signal bouncing back?

73 SR!

It is a Radio Direction Finder.Some U.S.Military Aircraft (and some of
the Allies Aircraft used them too) used them with a loop antenna mounted
on the Aircraft.
cuhulin

Ok so it was like a LORAN system.

SR

wrote:

It is a Radio Direction Finder.Some U.S.Military Aircraft (and some of
the Allies Aircraft used them too) used them with a loop antenna mounted
on the Aircraft.
cuhulin

"SR" wrote in message
...
Ok so it was like a LORAN system.

SR


No, LORAN uses time measurement.

A Radio Direction Finder basically points in the direction of a LW or MW
radio station.
Have you ever used an old AM radio with a ferrite rod antenna inside? If you
turn the radio around the signal drops out if the end of the radio is
pointed toward the AM broadcast antenna.

Old direction finders used big circular crossed loops, now ones use a block
of ferrite with two windings on them at 90°.
With a combination of signals driving servo amplifiers, it is possible to
drive a device called a Goniometer to a null position, ie no signal, then
read off the bearing.
With a bit of practice, you can do the same thing with an old transistor
radio. BUT - they aren't very accurate. 4 or 5 degrees was considered
excellent. If you are trying to get a bearing on a distant station, be sure
you are using the groun wave, as the ky wave can distort and come in from
different angles.

Most modern aircraft carry an ADF receiver, but some are being removed in
favour of GPS.

Brad.

Ok I have a Panasonic 2200 shortwave radio that has the ferrite rod
antenna on the top. Often I have to tell people that it is not a handle
dam it!

I once used it while driving from Florida to New York. As I got closer
heading north, I tune it to a strong NY station, and yes the signal got
stronger.

Now I understand what an trans-oceanic radio is. I am still looking for
information of the radio that C. Linberg used.

As a kid I use to take broken am transitor radios apart. Many of them
had a small ferrite rod inside. But I noticed that pocket radio (later
on known as walkman)did not have them.

Some ferrite rod look like a minature dipoles. Different tiny thead
wires coiled around. As a matter of fact I recently built a 90 feet per
side dipole coiled around pvc tubing, which is hollow. And I thought to
myself, what if I where to put a long iron pipe inside the top part of
the pvc tubing? -(looks like a T)

Also, thoughout the 1970's when big stereos became popular, (you know
the record player, 2 wooden speakers, radio with a long am/fm bandwith
with a cool red lighed niddle, silver face plate, solid state, 8track
and the girlfriend) many of them had an odd long plasic thing in the
back. It looked like something you would put your toothbrush in. LOL!

I would often say to myself: if that is an antenna, what a strange place
to put it!

As for LORAN, I think I hear the last of the LORAN signals while I was
in Florida. It was around 150 KHZ.

73 SR!

SR!

Brad wrote:

"SR" wrote in message
...

Ok so it was like a LORAN system.

SR



No, LORAN uses time measurement.

A Radio Direction Finder basically points in the direction of a LW or MW
radio station.
Have you ever used an old AM radio with a ferrite rod antenna inside? If you
turn the radio around the signal drops out if the end of the radio is
pointed toward the AM broadcast antenna.

Old direction finders used big circular crossed loops, now ones use a block
of ferrite with two windings on them at 90°.
With a combination of signals driving servo amplifiers, it is possible to
drive a device called a Goniometer to a null position, ie no signal, then
read off the bearing.
With a bit of practice, you can do the same thing with an old transistor
radio. BUT - they aren't very accurate. 4 or 5 degrees was considered
excellent. If you are trying to get a bearing on a distant station, be sure
you are using the groun wave, as the ky wave can distort and come in from
different angles.

Most modern aircraft carry an ADF receiver, but some are being removed in
favour of GPS.

Brad.

www.devilfinder.com World War Two Aircraft Radio Compass

My old buddy owns an ex U.S.Navy Ship Compass.He was in the U.S.Navy
active duty for four years on the U.S.S.Ticonderoga back in the early
1960's (they were shootin at Whales,Tonkin Gulf incident,at the same
time,I was humping ammo in Vietnam) and in the U.S.Navy Reserve unit
here in Jackson.One day they were getting rid of some old things at the
Reserve unit he retired from here in Jackson on Jefferson Street and
they gave him the Compass and an Anvil (I have been trying to talk him
out of that old Anvil for many years) and a few other things.One of the
balls was missing from the Compass (it is a big heavy Compass,stands
over waist high, and about twenty years later I was in Pensacola,Florida
and I saw a big store that sells antique nautitcal things and they had a
Compass ball in there for sale for $40.00.I phoned my old buddy long
distance and I asked him what diameter the Compass ball on his Compass
is.I bought that Compass ball at the store in Pensacola for him.
cuhulin

From: SR
Organization: Posted via Supernews, http://www.supernews.com
Reply-To:
Newsgroups: rec.radio.shortwave
Date: Sat, 01 Oct 2005 15:19:31 -0400
Subject: WW2 Radio Compass

As you know I am mad about radios, WW2 airplanes, tanks & subs.

I was thinking about getting a compass so that I could better find my
possition at home. So I did a search on Ebay on Compass. I then came
accoss something that is called a Radio Compass.
EBAY Item number: 6565758752

My guess it that the gauge is telling the pilot his dirrection in the
sky. But why is it called a radio compass?

Is the device putting out a signal? And is the signal bouncing back?

73 SR!
No, it's a radio receiver with a directional antenna. The display shows the
compass bearing to the radio station being received. There used to be
portable radios, usually the "all band" variety, that had built-in radio
direction finders (RDF's). Heathkit even had one, though I don't recall the
model number.

Greg

Greg wrote:

From: SR
Organization: Posted via Supernews, http://www.supernews.com
Reply-To:
Newsgroups: rec.radio.shortwave
Date: Sat, 01 Oct 2005 15:19:31 -0400
Subject: WW2 Radio Compass

As you know I am mad about radios, WW2 airplanes, tanks & subs.

I was thinking about getting a compass so that I could better find my
possition at home. So I did a search on Ebay on Compass. I then came
accoss something that is called a Radio Compass.
EBAY Item number: 6565758752

My guess it that the gauge is telling the pilot his dirrection in the
sky. But why is it called a radio compass?

Is the device putting out a signal? And is the signal bouncing back?

73 SR!
No, it's a radio receiver with a directional antenna. The display shows the
compass bearing to the radio station being received. There used to be
portable radios, usually the "all band" variety, that had built-in radio
direction finders (RDF's). Heathkit even had one, though I don't recall the
model number.

One of them was the DF-1:

http://www.heathkit-museum.com/other/df-1.shtml

dxAce
Michigan
USA

There is an old Humphrey Bogart movie (I don't remember the title of the
movie just now although I have seen it a bunch of times before) and
Humphrey plays the part of a bad guy in the movie and they are going to
steal the payroll from a gas plant.One of the crooks buys a tractor
tanker (sort of like an 18 wheeler) and a guy who is playing the part of
one of the crooks,but is really a copper,installs a radio tracking
device underneath the tanker so the coppers can trace the truck
tanker.It is a real good old Humphrey Bogart movie.
cuhulin

.... radio tracking
device underneath the tanker so the coppers can trace the truck....

That's "White Heat," a 1949 movie starring Jimy Cagney.

http://www.imdb.com/title/tt0042041/

"Made it, ma; top of the world."