Is it possible to have a radio that when the signal comes in, it can
tell you which dirrection it's from?????????????????????????????????

SR!

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.

Greg

SR wrote:
Is it possible to have a radio that when the signal comes in, it can
tell you which dirrection it's from?????????????????????????????????


Yes.

Cmdr Buzz Corey wrote:
SR wrote:
Is it possible to have a radio that when the signal comes in, it can
tell you which dirrection it's from?????????????????????????????????

Yes.

ITYM Yes!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!

--
If John McCain gets the 2008 Republican Presidential nomination,
my vote for President will be a write-in for Jiang Zemin.

Cmdr Buzz Corey wrote:

SR wrote:
Is it possible to have a radio that when the signal comes in, it can
tell you which dirrection it's from?????????????????????????????????


Yes.

ADF works well in aircraft for LF and MF
VOR works for VHF
TACAN works for UHF
and some military aircraft carry UHF DF
Plus, of course, ECM systems work throughout the spectrum.

Dave
Who has used them all, but long ago!

"Dave Holford" wrote in message
...


Cmdr Buzz Corey wrote:

SR wrote:
Is it possible to have a radio that when the signal comes in, it can
tell you which dirrection it's from?????????????????????????????????


Yes.

ADF works well in aircraft for LF and MF
VOR works for VHF
TACAN works for UHF
and some military aircraft carry UHF DF
Plus, of course, ECM systems work throughout the spectrum.

Dave
Who has used them all, but long ago!

I am reading his question for the point of view of DF'ing ANY radio signal
in an effort to gain knowledge of it's possible source.

VOR is a deliberately phase modulated signal, as is TACAN. Not much point
DF'ing them from a ground station since their location is known, or can be
found from the Ident. Now UHF DF certainly has some applications,
particularly if DX'ing FM broadcast stations, but so would a yagi and a
rotator.

Since the newsgroup is r.r.shortwave, then DF'ing shortwave seems to me to
be the topic. Here is another method worth trying, particularly because of
it's compact size. http://www.qsl.net/dj3tz/loop1.html

Brad.

"Brad" (bradvk2qq AT w6ir.com) writes:


Since the newsgroup is r.r.shortwave, then DF'ing shortwave seems to me to
be the topic. Here is another method worth trying, particularly because of
it's compact size. http://www.qsl.net/dj3tz/loop1.html

And a significant point is that a "radio compass" was so simple, because
it was at a time when applications for radio was relatively small. The
more complicated systems came later, when things had built up and a
need for something better came along.

Direction finding has come to mean tracking down an unknown station, but
in the case of a Radio Compass the scheme is identical, using a directional
antenna and a basic receiver, but you pick a station you know the location
of, so when you point to it you know you are going the right direction
(unless you pick the wrong side of the null, and go 180 degrees in
the wrong direction, but there were ways of fixing that).

While there were beacon stations set up for Radio COmpass use, I gather
it was not uncommon to use existing broadcast stations for the purpose.

Were talking sixty to seventy years ago when they first started using
Radio Compasses.

Michael

"Michael Black" wrote in message
...

"Brad" (bradvk2qq AT w6ir.com) writes:


Since the newsgroup is r.r.shortwave, then DF'ing shortwave seems to me
to
be the topic. Here is another method worth trying, particularly because
of
it's compact size. http://www.qsl.net/dj3tz/loop1.html

And a significant point is that a "radio compass" was so simple, because
it was at a time when applications for radio was relatively small. The
more complicated systems came later, when things had built up and a
need for something better came along.

Direction finding has come to mean tracking down an unknown station, but
in the case of a Radio Compass the scheme is identical, using a
directional
antenna and a basic receiver, but you pick a station you know the location
of, so when you point to it you know you are going the right direction
(unless you pick the wrong side of the null, and go 180 degrees in
the wrong direction, but there were ways of fixing that).

While there were beacon stations set up for Radio COmpass use, I gather
it was not uncommon to use existing broadcast stations for the purpose.

Were talking sixty to seventy years ago when they first started using
Radio Compasses.

Michael

That's right. A Radio compass is like DF'ing in reverse. I know where you
are, so where am I?
ADF is still an approved and popular form of aircraft navigation. The VLF
beacons are maintained for that purpose.

Whilst broadcast stations were also used for navigation, it was not really a
recomended practice. The radiation pattern could change, but more
importantly, without a proper identification, it was possible to DF on the
wrong transmitter, sharing the same frequency. If they carried the same
music program, there may be no way to know until the pilot is truly lost.
That said, the ABC station near us is called 2RN and is the inbound
checkpoint. That's mostly because it is a big thing with flashing lights.

Where is SR located? If he tells us his home town or local airport, we'll
find a beacon for him to practice on.

Brad.

Brad I am in Queens New York. Sometimes I like to find beacons when
nothing else is on the band.

Within my 10-20 or so radius area their are two big air port and not far
from the Atlantic. I noice that on the upper part of the medium band I
sometimes pick up a CW beacon. I belive it's a beacon because it
repeats it's self in perfect timming. I had not yet decoded the message
yet.

Now, MFJ sell an interesting device, it's looks like a black flat box
with numbers and red lights on them. The device is suppose to read all
beacons nation wide.

Do you know anything about that? And how does this work? And is WWV
that voice that gives the UTC on 10000.0 MHZ?

73 SR!



Brad wrote:

"Michael Black" wrote in message
...

"Brad" (bradvk2qq AT w6ir.com) writes:



Since the newsgroup is r.r.shortwave, then DF'ing shortwave seems to me
to
be the topic. Here is another method worth trying, particularly because
of
it's compact size. http://www.qsl.net/dj3tz/loop1.html

And a significant point is that a "radio compass" was so simple, because
it was at a time when applications for radio was relatively small. The
more complicated systems came later, when things had built up and a
need for something better came along.

Direction finding has come to mean tracking down an unknown station, but
in the case of a Radio Compass the scheme is identical, using a
directional
antenna and a basic receiver, but you pick a station you know the location
of, so when you point to it you know you are going the right direction
(unless you pick the wrong side of the null, and go 180 degrees in
the wrong direction, but there were ways of fixing that).

While there were beacon stations set up for Radio COmpass use, I gather
it was not uncommon to use existing broadcast stations for the purpose.

Were talking sixty to seventy years ago when they first started using
Radio Compasses.

Michael


That's right. A Radio compass is like DF'ing in reverse. I know where you
are, so where am I?
ADF is still an approved and popular form of aircraft navigation. The VLF
beacons are maintained for that purpose.

Whilst broadcast stations were also used for navigation, it was not really a
recomended practice. The radiation pattern could change, but more
importantly, without a proper identification, it was possible to DF on the
wrong transmitter, sharing the same frequency. If they carried the same
music program, there may be no way to know until the pilot is truly lost.
That said, the ABC station near us is called 2RN and is the inbound
checkpoint. That's mostly because it is a big thing with flashing lights.

Where is SR located? If he tells us his home town or local airport, we'll
find a beacon for him to practice on.

Brad.

Brad wrote:


Whilst broadcast stations were also used for navigation, it was not really a
recomended practice. The radiation pattern could change,


Doesn't matter if the radiation pattern changes, if you can still
receive the signal you still know the direction.

UHF DF certainly has some applications, particularly if DX'ing FM broadcast
stations, but so would a yagi and a rotator.

It's also useful for homing on UHF NDBs. Pretty hard to put a Yagi and rotator
on a Navy aircraft.

Dave