In WWII the allies were able to pinpoint the locations of German HF
transmissions very accurately. They were able to pinpoint the
locations of U-boats, etc. when they transmitted. (or so I have been
led to believe).

What methods did they use to do this? Is it something duplicatable
with Radio Amateurs in general or does it require some special type
equipment?


I hear lots of amateurs describing interference and other problems on
HF, but no one seems to be triangulating the offending stations. I am
guessing that the real secret was in their communications with the
'spotters' to triangulate the positions.

Any suggestions?

Thanks

--
73 for now
Buck
N4PGW

"Buck" wrote in message
...
In WWII the allies were able to pinpoint the locations of German HF
transmissions very accurately. They were able to pinpoint the
locations of U-boats, etc. when they transmitted. (or so I have been
led to believe).

What methods did they use to do this? Is it something duplicatable
with Radio Amateurs in general or does it require some special type
equipment?


I hear lots of amateurs describing interference and other problems on
HF, but no one seems to be triangulating the offending stations. I am
guessing that the real secret was in their communications with the
'spotters' to triangulate the positions.

Any suggestions?

Thanks

--
73 for now
Buck
N4PGW


Triangulating and so on, can and does work. You're talking a difference
between "war" and the need to know - vs - finding an offending station - to
shut it down, etc. The FCC isn't as involved as many would like to think.
They can't keep up with it. For others to do so, would be nothing short of
vigilante-ism. It's not worth being jailed or shot - trying to shut down an
offending station. Not to mention, most signals heard over hundreds or
thousands of miles away. Who really cares? Would you be willing to travel
the 1000 miles to put a stop to it? Probably not. Most new people can't
change a fuse - let alone triangulate. They're lucky they recall what a
resistor or capacitor is or does or even looks like once they put the book
down.

On Thu, 17 Feb 2005 03:32:48 -0500, "cl" wrote:

Triangulating and so on, can and does work. You're talking a difference
between "war" and the need to know - vs - finding an offending station - to
shut it down, etc. The FCC isn't as involved as many would like to think.
They can't keep up with it. For others to do so, would be nothing short of
vigilante-ism. It's not worth being jailed or shot - trying to shut down an
offending station. Not to mention, most signals heard over hundreds or
thousands of miles away. Who really cares? Would you be willing to travel
the 1000 miles to put a stop to it? Probably not. Most new people can't
change a fuse - let alone triangulate. They're lucky they recall what a
resistor or capacitor is or does or even looks like once they put the book
down.


I wasn't proposing that they 'shut them down' but to triangulate them.
I don't know how accurate the locations were during the war, but I
hear they were pretty accurate.

I think you agreed with my assumption that, basically, it is a matter
of amateurs not being coordinated, or more accurately from you, not in
the right location.

Sometimes the offending station is nothing more than a stuck keyer,
but sometimes it is intentional interference.

As for the competency, I hate to admit it, but sometimes what I see
leads me to believe my IQ must be about 250. That isn't to offend
those with high IQ's as those who have a real-life 200 IQ must be the
equivalent of about 600 now.

Oh well, off the soapbox.

I wonder if there would be any interest in long-range fox hunts (not
the QRP version.)

--
73 for now
Buck
N4PGW

"Buck" wrote in message
...
On Thu, 17 Feb 2005 03:32:48 -0500, "cl" wrote:


As for the competency, I hate to admit it, but sometimes what I see
leads me to believe my IQ must be about 250. That isn't to offend
those with high IQ's as those who have a real-life 200 IQ must be the
equivalent of about 600 now.

Oh well, off the soapbox.

I wonder if there would be any interest in long-range fox hunts (not
the QRP version.)

--
73 for now
Buck
N4PGW

Being one of the new nocode techs, I have no illusions re my overall radio
technical competency. I have one slight advantage over my newbie brethren
though. Having been a Jr. High shop teacher (woodwork, metalwork, drafting,
and electricity) I at least have some idea where to look for info that will
allow me to identify basic electronic components. Perhaps with license
upgrades I'll widen my knowledge and competency base, but for now antenna
building is my main DIY interest and such expertise is not yet required.
Your comments on IQs is interesting. Many businesses, after laying off older
workers for years, seem to be actively seeking elders again. Perhaps they've
decided that it's desirable to have at least some employees that can both
read and make change without a pocket calculator.(G)

Harold
KD5SAK

Buck wrote:
"What methods did they use to do this?"

Terman says on page 1046 of his 1955 "Electronic and Radio Engineering::
"The fact that radio waves propagate away from the transmitter alomg a
great-circle route makes radio direction finding a useful navigational
aid."

Ships and aircraft have been equipped with shielded loop antennas for
direction finding. At frequencies below 500 KHz,bearings can be read
within 1%.

Ionospheric reflection so scrambles polarizations at higher frequencies,
that loop bearings have higher errors.

An Adcock beam antenna can be made to ignore horizontally polarized
waves from a certain direction and respond to only the vertically
polarized waves. It suffers from very low signal pickup as compared with
a loop, but gives accurate bearings at high frequencies over a distance
of 100 miles where a loop would be useless.

In WW-2, aircraft and ships were often equipped with radios such as the
Bendix RA-1B multiband receiver and a loop antenna, or the navy `s
AN//ARC-5 equipment for direction finding.

Best regards, Richard harrison, KB5WZI

Great Britain had many antenna farms located many miles apart for direction
finding.

--

73
Hank WD5JFR
"Buck" wrote in message
...
In WWII the allies were able to pinpoint the locations of German HF
transmissions very accurately. They were able to pinpoint the
locations of U-boats, etc. when they transmitted. (or so I have been
led to believe).

What methods did they use to do this? Is it something duplicatable
with Radio Amateurs in general or does it require some special type
equipment?


I hear lots of amateurs describing interference and other problems on
HF, but no one seems to be triangulating the offending stations. I am
guessing that the real secret was in their communications with the
'spotters' to triangulate the positions.

Any suggestions?

Thanks

--
73 for now
Buck
N4PGW

Some years ago, the local gov department (fcc to you) here in aus carried
out test on their hf df. They were able to pinpoint a station in soth
australia within about 1 km or so. Impressive I thought at the time.

JE

"Buck" wrote in message
...
In WWII the allies were able to pinpoint the locations of German HF
transmissions very accurately. They were able to pinpoint the
locations of U-boats, etc. when they transmitted. (or so I have been
led to believe).

What methods did they use to do this? Is it something duplicatable
with Radio Amateurs in general or does it require some special type
equipment?


I hear lots of amateurs describing interference and other problems on
HF, but no one seems to be triangulating the offending stations. I am
guessing that the real secret was in their communications with the
'spotters' to triangulate the positions.

Any suggestions?

Thanks

--
73 for now
Buck
N4PGW

Buck, N4PGW wrote:
"Is it something duplicable with Radio Amateurs in general or does it
require some special type of equipment?"

Much British success in WW-2 in eavesdropping on German transmissions
had as much to do with information processing as it had to do with its
interception.

Germans used an "Enigma Machine" which was easily reset for a new code.
They often changed the code and it was quite complicated. Germans used
the machines to encode and decode their confidential messages. Early in
the war, an Enigma Machine was captured. British code experts worked
long, hard, and smartly to determine how the machine worked and broke
its codes. Afterwards, the British were silent parties on the German`s
war partyline. The British sometimes feigned ignorance so as not
announce their access to Germany`s most secret information. It was a big
factor in victory.

Stationary direction finding can take the directional antenna arrays
used for transmitting and use them for receiving insteaad. Reciprocity
means that the reception pattern is identical to the transmitting
pattern. I have no idea what the British did in their enemy reception
stations in WW-2. For HF, they could have used Yagi-Uda`s on rotators
and indicators. They also could have used crossed loops or Adcocks,
feeding a goniometer and not rotated the antenna. Terman shows how this
is done on page 1051 of his 1955 edition.

During the "Cold War", when I worked in HF broadcasting, Radio Free
Europe diligently monitored, recorded, and processed broadcasts from
behinnd the "Iron Curtain". All the Communist news and commentary that
was fit to broadcast from their point of view. To pick the desired
transmissions from among the babble, some RFE receiving stations had the
appearance of medium-wave multi-tower broadcast stations. Towers were
tuned and phased to null interference and to grab the desired
transmission. Other stations used sizeable loops. Some had air for a
core and some had huge ferrite cores. Whatever proved best was used in
any case..

Hams can surely use directional antenna systems.

Best regards, Richard Harrison, KB5WZI

In message , Richard
Harrison writes
Buck, N4PGW wrote:
"Is it something duplicable with Radio Amateurs in general or does it
require some special type of equipment?"

Much British success in WW-2 in eavesdropping on German transmissions
had as much to do with information processing as it had to do with its
interception.

snip

Stationary direction finding can take the directional antenna arrays
used for transmitting and use them for receiving insteaad. Reciprocity
means that the reception pattern is identical to the transmitting
pattern. I have no idea what the British did in their enemy reception
stations in WW-2. For HF, they could have used Yagi-Uda`s on rotators
and indicators.

Too broad a beam. Loop zeros are sharper.

They also could have used crossed loops or Adcocks,
feeding a goniometer and not rotated the antenna.

Correct.

U-boats used HF for reporting back to base in Lorrient, but MF for talk
among themselves in the Wolfpack. It was this that was DFed by the
shipborne CRT DF.

Mike

Brings back scenes from old WWII movies where the Germans were closing in on
an Allied spy, with a suitcase radio set, sending from an upstairs flat, in
the dark of night. Vans crawling along with loop antennas on the roof, and
guys inside with comm gear and headphones telling the driver where to go,
etc.

Wonder if loop antennas were what they really used, and how good they were?
The spies generally used cw. How do you get a fix on the short dots and
dashes?