How about the Broom, surely this will detect a digital recorder ?
Regards
DMMG
From: tscm-..._at_googlegroups.com [mailto:tscm-..._at_googlegroups.com] On Behalf Of James M. Atkinson
Sent: Monday, October 25, 2010 1:10 AM
To: tscm-..._at_googlegroups.com
Subject: Re: [TSCM-L] {5128} Re: {5085} the best way to find digital recorders
A NJLD will provide unreliably results, and a high probability of a missed eavesdropping device.
A spread spectrum NLJD will give better results, and a broad band "chirped" or "swept" NLJD will give even better results.
If you can use an spectrum analyzer that has a "discontinuous sweep generator" as part of the spectrum analyzer then you can use the spectrum analyzer itself as an NLJD and there will be zero reason to haul a NLJD to the job site. The ESA-E is a good example of this where you can illuminate at one frequency, and have the SA display only the harmonics of where you are illuminating, and give you audio of the signal via the Y/Z axis output.
It is pretty cool to turn a spectrum analyzer into the the Mother-of-all-NLJD's
-jma
Humberto Sodre wrote:James,
The best way to find a digital recorder or any device that is not broadcasting an RF signal with good intensity, is not to use a non-linear junction detector?
Humberto Rigotti
2010/10/24 James M. Atkinson <jm..._at_tscm.com>
The loop antenna that you describe will help a little, but as the frequencies get lower and lower the geometry of the antenna starts getting cumbersome, things start getting larger, and is you use a sideband antenna is is very easy to saturate the entire band that you are trying to filter, the specific frequency you are seeking is not finely dialed in, and it can be tricky to use for this.
Yes, the loop and bandpass filter will work, and I have used them in the past like this. But I got vastly better results when I wound a single bar antenna of a very specific frequency, and tunes it so that essentially it was a huge filter itself. Then I ran it into a small concentrator ring inside the frequency specific antenna, and then outside of the antenna passed the signal into a BPF attached to a ultra-low noise pre-amplifier.
cptkaos wrote:How effective would a bandpass filter (say 32.0 KHz - 32.9 KHz) bewhen used with a loop antenna with the range of 20 Hz to 50 KHz?On Oct 18, 2:51 pm, "James M. Atkinson" <..._at_tscm.com> wrote:The optimal electronic way is to use a magnetic antenna, in the form ofa small loop of ferrite core with a very sharp bandpass filter at 32.768kHz. A good rule is that if you can "hear" the timing crystal on adigital from 2 feet away you should be able to "hear" any magneticradiation coming off a digital recorder.A very sophisticated digital recorder that presents miniscule amounts ofRF energy will often provide a considerable magnetic signal if you knowwhat to watch for.The spy is going to deal with a very large and very heavy enclosure tokeep this leakage down, but since most spies obsess on keeping theirdevices small they compromise the detection of magnetic signals.I have some very nice stick antenna's that I have made that are resonantright at 32.768 kHz, and they are easy enough to build and impedancematch to a 50 ohm filter, and then to a 50 ohm pre-amp, but get thepreamp well away from the antenna and use double shielded cables foreverything. It does involve thousands of loops of wire, some carefuluse of capacitors, a ferrite loop, and a piston cap to settle it righton frequency.-jmaDavid Rom wrote:Hi TSCM expertswhat is the best way to fins digital recorders in while we sweep a room?David RomGD Intelligence Security LTD.On Sat, Oct 2, 2010 at 5:54 PM, <soca..._at_aol.com<mailto:soca..._at_aol.com>> wrote:Bug Hunting with Anritsu's Spectrum Master�http://www.youtube.com/watch?v=jGv3nNSIsfo--You received this message because you are subscribed to theGranite Island Group "TSCM-L Professionals List" group which isthe oldest, and the largest TSCM group on Earth. To post to thisgroup, send E-Mail to TSCM-..._at_googlegroups.com<mailto:TSCM-..._at_googlegroups.com>, to contact the list ownerand moderator please send an E-Mail message to j..._at_tscm.com<mailto:j..._at_tscm.com>.This group is sponsored by Granite Island Grouphttp://www.tscm.com/to improve the profession of hunting spies,and to educate others in the craft of technicalcounter-intelligence. Granite Island Group performs bug sweepslike it's a full contact sport; we take no prisoners, we don'tplay fair, and we give no quarter. Our professional goal is tosimply, and completely stop the spy.Granite Island Group Offers World Class, Professional, Ethical,and Competent Bug Sweeps, and Wiretap Detection usingSophisticated Laboratory Grade Test Equipment.--You received this message because you are subscribed to the GraniteIsland Group "TSCM-L Professionals List" group which is the oldest,and the largest TSCM group on Earth. To post to this group, sendE-Mail to TSCM-..._at_googlegroups.com, to contact the list owner andmoderator please send an E-Mail message to j..._at_tscm.com.This group is sponsored by Granite Island Grouphttp://www.tscm.com/to improve the profession of hunting spies, and to educate others inthe craft of technical counter-intelligence. Granite Island Groupperforms bug sweeps like it's a full contact sport; we take noprisoners, we don't play fair, and we give no quarter. Ourprofessional goal is to simply, and completely stop the spy.Granite Island Group Offers World Class, Professional, Ethical, andCompetent Bug Sweeps, and Wiretap Detection using SophisticatedLaboratory Grade Test Equipment.--James M. AtkinsonPresident and Sr. EngineerGranite Island Groupjm..._at_tscm.comhttp://www.tscm.com/- Hide quoted text -- Show quoted text -
--James M. AtkinsonPresident and Sr. EngineerGranite Island Groupjm..._at_tscm.comhttp://www.tscm.com/
--James M. AtkinsonPresident and Sr. EngineerGranite Island Groupjm..._at_tscm.comhttp://www.tscm.com/
-- James M. Atkinson President and Sr. Engineer Granite Island Group jm..._at_tscm.com http://www.tscm.com/Received on Sat Mar 02 2024 - 00:57:24 CST
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