This NLJD was known as the Broom (Model 400 - sold in the US for a period of time in the mid '80's by Winkelman Countermeasures Inc, located in Tempe, AZ). It operated at Approximately 455 MHz and had a (Legal in US) rated output of 100 Mw of RF power. If memory serves me, all commercial grade units sold in the US are limited to 100 Mw of RF output. Equipment sold to government agencies, or designated for export, can be designed (or tuned) to operate at higher output.
I have two of the older Broom's, operating (illegally) at the 454 MHz frequency. They could have been FCC approved for that frequency if management had left us alone when we was coordinating with FCC; they tried to play the political influence game and the people at FCC told them what they could do with their rolling donut.
About two to three years ago, a friend and I did some comparison testing of the Broom, the ISA Boomerang and the Locator (another NLJD, operating at about 900 MHz, built in and exported from Great Britain), all putting out the legal amount of power for the US and found there was very little difference in distance at which an electronic device could be located. They all performed, essentially, identically. We taped our test devices on a clean wall with nothing on the other side and did the locate thingy from different angles---result, little difference.
I hope this helps answer your initial question.
For the second part:
The NLJD is NOT a listening device---nor is the hand held walkie talkie you carry around. BUT, both can be hazardous to you communications security health if used improperly or in the wrong place.
The problem in using any type transmitting device is one called RF Flooding. What happens is the energy from a transmitting device (NLJD, walkie talkie, cellular phone) "floods" nearby electronic equipment, often causing them to re-radiate a signal containing intelligence on a different frequency. That, essentially, is what occurred with The Great Seal in the Ambassadors office in Moscow. A resonant cavity was bombarded with a radio signal and audio was re-radiated on a different frequency. From experience, I can guarantee two things happening if someone is using the NLJD in a different office and you're running an RF at the same time---you'll get an adrenalin rush that is great and the pucker factor goes out of sight.
Feel free to contact me for more info.
Tim Johnson
Through a combination of physical and electronic examinations of the incoming telephone lines it was determined that two telephone lines were serviced by a single outgoing telephone pair. This was accomplished through the process of digitizing the audio from the telephones at a Multiplex Twoline Digital Carrier interface built into the cover of the telephone box mounted on the outer rear wall of the residence. This interface electronically combines the analog signal from each telephone/fax and converts it to digital information which is then relayed down the telephone lines to the telephone company central office, at which point it is converted back to analog and processed as independent signals.
You were dealing with lines coming from two different switches/power supplies. Either one CO line and two SLIC's, two different CO's, or one CO housing two different switches. With a 40 VDC on-hook showing, my guess is that they were SLIC lines. More background info on the location of this residence would nail it down.
Moral of the story. Its not just residential clients who are sometimes schizophrenic. Sometimes their phone lines are too.
Kevin
I remember the hostage situation and you guys responding. I was never lucky enough to have a corporate sized jet diverted for me, only once with a KC-135. Back to the hostage situation: what a zoo that was -- the guy actually broke out of jail and did it again after that too. They then sent him off to some psychiatric hospital under heavy armed escort. It was his ex wife he held hostage, along with their infant child. Remember? It was Blytheville, not Little Rock.
I also remember the tech assistance - don't recall it as we were always
about to lose a case when we called you guys in. But tech certainly
helped us out. Lots. More than once. I used to work lots with IVT at
Dist 20 when I was an RFC. They even gave me a tech call sign for my
radio: JAFTA-9 (don't remember the number, but do remember JAFTA. "Just
Another F------- Tech Agent". I'm sure you've heard that one.
Take care of yourself - happy Thanksgiving.
Fred
Actually, as the stand in for Superman AND the six million dollar man we traveled so much we seldom are able to remember where we went and what we did (I still suffer from not knowing what I'm doing), but he's right It was Blytheville Arkansas. I do remember the subject was armed and I asked for TWO bullet proof vests be waiting when I arrived; so did Penny Lloyd. We were scheduled to go into the unoccupied part of the on base duplex and install a camera/microphone to get some idea of where the guy was located so they could plan a way to get to him.
No, never in the Thai, but I did a couple of tours in Korea.
Hi Tim,
Good to see the board back up and running. I've actually had some good results with the Radio Shack 170 MHz wireless mics. If you take them out of the cigarette pack sized case you have two pc boards that can be placed inside target objects, and if you boost B+ to around 12 volts you actually get a low cost transmitter with a useful range for many hotel type applications.
Trace Carpenter Investigations ******
2926 Maple Ave., Ste. 200 Ignorance of the law is no excuse;
Dallas, Texas 75201 Ignorance of the law makers apparently is
214.828.4520 ******
214.740-0112 Facsimile
Anyhow, I need more input and questions for the forum..
Tim Johnson