uusgta@sw1e.UUCP (03/23/87)
I was thinking about the commonly mentioned electronic snooping technique of pasting a reflective dot to a window and listening to conversations in the room by bouncing a laser off this vibrating mirror. How *could* such a signal be encoded? Short bursts of light and time based sampling? Backscattered signal strength measurements of some sort? Doppler shifts? Anyone know or got suggestions? -- # ---Tom Adams--- # {bellcore,ihnp4}!sw1e!uusgta St. Louis MO 314-235-4237 # Opinions expressed here are mine, not those of Southwestern Bell Telephone
greg@endor.UUCP (03/26/87)
In article <499@sw1e.UUCP> uusgta@sw1e.UUCP (uusgta) writes: >I was thinking about the commonly mentioned electronic snooping technique >of pasting a reflective dot to a window and listening to conversations in the >room by bouncing a laser off this vibrating mirror. My understanding is that a window is reflective enough by itself that you don't need to put anything on it in order for this device to work. This way you can bug a room without ever being within 100 feet of it. >How *could* such a signal >be encoded? Probably the reflected laser light is combined with the laser source, and the interference pattern is measured. The coherence length of the laser must be much greater than the distance from the laser to the window. ---- Greg
yerazuws@rpics.UUCP (03/27/87)
In article <499@sw1e.UUCP>, uusgta@sw1e.UUCP (uusgta) writes: > I was thinking about the commonly mentioned electronic snooping technique > of pasting a reflective dot to a window and listening to conversations in the > room by bouncing a laser off this vibrating mirror. The technique works by interferometry. As the dot moves, the distance between the dot and the laser changes. By creating an interference pattern, it can be determined how far and in which direction it moved. By the way, you really don't need the dot. A dirty window is enough. -- -Bill Yerazunis "VAXstation Repo Man" -->Copyright (c) 1987. Restrictions on Redistribution PROHIBITED <--
dave@onfcanim.UUCP (03/29/87)
In article <499@sw1e.UUCP> uusgta@sw1e.UUCP (uusgta) writes: >I was thinking about the commonly mentioned electronic snooping technique >of pasting a reflective dot to a window and listening to conversations in the >room by bouncing a laser off this vibrating mirror. How *could* such a signal >be encoded? One suggestion: The coherence length of a stabilized laser can be several hundred meters. Thus, you can send a beam 100 meters to a reflector, have it return, mix it with a sample of the beam coming from the laser, and get interference fringes. The movement of these fringes measures the change in distance between the interferometer assembly and the reflector to a resolution of less than a wavelength of light. Of course, the interferometer has to be on a very vibration-free mount for this to work. A much simpler possibility: if the mirror is mounted near the edge of the pane of glass, it will rotate as well as translate as the window flexes. The rotation will change the angle of the reflected beam, and this angular change may be measurable. However, the window will flex far more due to wind, air pressure changes when doors are opened, etc, probably making the desired signal hard to extract. I haven't tried any of these.
levy@ttrdc.UUCP (03/29/87)
In article <1505@husc6.UUCP>, greg@endor.harvard.edu (Greg) writes: <In article <499@sw1e.UUCP> uusgta@sw1e.UUCP (uusgta) writes: <<I was thinking about the commonly mentioned electronic snooping technique <<of pasting a reflective dot to a window and listening to conversations in the <<room by bouncing a laser off this vibrating mirror. <My understanding is that a window is reflective enough by itself that you don't <need to put anything on it in order for this device to work. This way you can <bug a room without ever being within 100 feet of it. <<How *could* such a signal <<be encoded? <Probably the reflected laser light is combined with the laser source, and the <interference pattern is measured. The coherence length of the laser must be <much greater than the distance from the laser to the window. If a reflective dot were not used, the laser would almost certainly need to be one with an invisible wavelength (infrared or ultraviolet). Otherwise, there'd be a telltale spot of light on any solid object in the beam's path on the other side of the window. (Or the laser beam could be reflected off at a sufficiently small angle to the plane of the glass so as not to penetrate, but that would require the sensor and the laser to be at different sites.) Come to think of it, sunlight, moonlight, or already-present artificial sources of direct light might even be used with an appropriately placed sensor. In this case interference patterns couldn't be used because the light isn't laser light. But maybe instead some kind of aperture could be used in front of the detector, such that as the edge of the reflected light pattern moved back and forth (presuming some angular displacement of the window), light would shine through less or more of the aperture and thus produce a greater or lesser instantaneous output from the detector. (This would be like "slope detection" of FM on an AM receiver, with physical displacement corresponding to frequency). OBLIGATORY STEENKING DISCLAIMER: Don't try this at home on your big sister's window, kiddies. She'll smack you sillier than you already are, even if it IS for your junior high school science fair project.... -- |------------dan levy------------| Path: ..!{akgua,homxb,ihnp4,ltuxa,mvuxa, | an engihacker @ | vax135}!ttrdc!ttrda!levy | at&t computer systems division | Disclaimer: try datclaimer. |--------skokie, illinois--------|
uusgta@sw1e.UUCP (03/31/87)
In article <560@sdiris1.UUCP>, res@sdiris1.UUCP (Robert Sanders) writes: > The modulation is simple, good old Amplitude modulation.. that is, a > continuous laser, which will be amplitude modulated by the vibration of > the window. (you can do this with a mirror connected to a voice box and > a reflected sunbeam, with a photodetector for recovering the signal) > Skip Sanders : sdcsvax!jack!man!sdiris1!res If/when you locate the construction project I would appreciate a reference. AM modulation doesn't seem terribly possible unless I misunderstand. Correct me if I'm wrong but I would think that the only amplitude variability would be attenuation due to different return path length (i.e. as the window vibrates inward the beam travels further to get back to the xmitter.) For any real distance I would expect this signal to get swamped quickly. Interferometry seem more reasonable. Asking a physics type person around here cleared up some things for me. Where I had thought that this sort of translation was many quick measures of distance he points out that the number of constructive/ destructive interferences per unit time is an indication of velocity. I hadn't heard of interferometers being used for anything other than precise measurements of distance, on the order of a part of a wavelength. He also points out that there are two components here. The gross travel of the window, as a function of sound level, and the "wiggle" of the window, as a function of frequency. He also points out that a reflective dot helps in determining which surface of the pane is reflecting. I have a few questions. 1) Can someone think of a method for determining the sign of the velocity of the window at a given time. It seems that waiting for acceleration to pass zero is the only indication of the window passing back through an earlier position. 2) Does anyone have a "feel" for the travel distances of the window? 3) Any thoughts on using a second imposed frequency on the laser? How could this help? Also what of lower frequency beams? Limits on frequency? 4) Are fourier transforms the appropiate tool to seperate volume and frequency information. 5) Could someone decribe the inerferometer setup. How would you prevent vibration at the measuring site from ruining the measure? -- # ---Tom Adams--- # {bellcore,ihnp4}!sw1e!uusgta St. Louis MO 314-235-4237 # Opinions expressed here are mine, not those of Southwestern Bell Telephone
res@sdiris1.UUCP (03/31/87)
> >I was thinking about the commonly mentioned electronic snooping technique > >of pasting a reflective dot to a window and listening to conversations in the > >room by bouncing a laser off this vibrating mirror. > >How *could* such a signal > >be encoded? I have a constuction project for this somewhere in my pile of spy gear manuals, but until I locate it, my recall is that yes, to get a usable bug at a real-world distance, you must put a reflective dot on the window. (At short range, you can do without) The modulation is simple, good old Amplitude modulation.. that is, a continuous laser, which will be amplitude modulated by the vibration of the window. (you can do this with a mirror connected to a voice box and a reflected sunbeam, with a photodetector for recovering the signal) The real units use telescopes for beam direction (in both directions) and usually use photo-multiplier tubes for sensitivity. Range on a real world (expensive) unit is about a mile, maximum (with the dot) or a hundred yards maybe without the dot. Note that ambient traffic noise will obscure the signal, so there is really not much use of these gadgets in normal city areas. -- Skip Sanders : sdcsvax!jack!man!sdiris1!res Phone : 619-273-8725 (evenings)
ron@brl-sem.UUCP (04/01/87)
We tried this rather crudely one day. Using a sheet of aluminum foil draped accross a stereo speaker (simulating the window) a friend shone a laser at the foil, the reflection's modulation is viewed as a scattering or visible wiggle of the beam, not as a simple distance change. Detection was done with a cheapo photoresiter in a kaliedoscope with walkman headphones arrangement that someone got out of a science toy kit. -Ron
roy@phri.UUCP (04/01/87)
In article <15260@onfcanim.UUCP> dave@onfcanim.UUCP (Dave Martindale) writes: > if the mirror is mounted near the edge of the pane of glass, it will > rotate as well as translate as the window flexes. The rotation will > change the angle of the reflected beam, and this angular change may be > measurable. An idea for a detector based on this idea: Assuming that the movement of the glass is small, the angle of deflection of the beam will also be small, so you can assume that the distance the beam is deflected is in direct proportion to the angle of deflection. Make a mask with a narrow slit in it which is wide at one and and narrow at the other. The wide end should be just smaller than the beam width, the narrow end should come to a point (i.e. zero width). The amount of light coming through the slit should now be a linear function of where along the slit the beam hits. Just measure the total amount of laser light striking a photorecepter behind the slit. If you want to get fancy, you can modulate the beam as it leaves the laser and put the signal output of the photoreceptor through a bandpass filter centered on this frequency (this will mask out incident light); now the voice signal will appear as AM modulation on top of the carrier you originally used to modulate the beam with. One problem might be that I've assumed a lot of linear steps; air pressure in the room to window flexing; window flexing to beam deflection, etc. If you really want to get fancy, calculate the real transfer function for voice -> room air pressure -> window flexing -> beam deflection. Now, instead of making the slit a linear taper, cut the slit to be the inverse of that transfer function and you compensate for all those nonlinearities in one step! All the various random signals like wind and doors opening and closing just get lost as out-of-band signals when you demodulate. -- Roy Smith, {allegra,cmcl2,philabs}!phri!roy System Administrator, Public Health Research Institute 455 First Avenue, New York, NY 10016 "you can't spell deoxyribonucleic without unix!"
howard@cpocd2.UUCP (04/02/87)
In article <503@sw1e.UUCP> uusgta@sw1e.UUCP (uusgta) writes: > 1) Can someone think of a method for determining the sign of the > velocity of the window at a given time. It seems that waiting > for acceleration to pass zero is the only indication of the window > passing back through an earlier position. Quadrature. You need two (or more) closely-spaced detectors. One will lead when the velocity is one way, and the other way the other will be leading. > 5) Could someone decribe the inerferometer setup. How would you > prevent vibration at the measuring site from ruining the measure? You just need to make sure it's smaller than the motion of the beam. If you use angular effects instead of distance ones, then the farther away you are the bigger deflection you get! It was not uncommon in the 60's & 70's for a "light show" at a rock concert to use a light beam bounced off of a mirror attached to a speaker or special double (stereo) speaker, giving the effect of an X-Y oscilloscope projected on the wall. Similar techniques on a smaller scale allow piezoelectric control of laser beam scanning. -- Copyright (c) 1987 Howard A. Landman. Transmission of this material constitutes permission from the intermediary to all recipients to freely retransmit the material within USENET. All other rights reserved.
res@sdiris1.UUCP (04/02/87)
Ummm... I goofed somewhat on my first posting... found the bugging techniques book involved, and the circuit given is for a laser diode, pulsed at approx. 10 KHz, and the recieved signal is described as being "pulse width modulated" ( which is equivilent to am, for the purposes of detection by simple analog detectors ). The book also mentions the possibility of using doppler/interferometric methods with a continuous laser. - Skip the forgetfull one - -- Skip Sanders : sdcsvax!jack!man!sdiris1!res Phone : 619-273-8725 (evenings)
wam@cdx39.UUCP (04/02/87)
[discussion of detecting beam through tapered slit] Trouble is, you need to find the orientation of the axis of rotation of the bit of window you are illuminating. Note that this axis may depend on vibrational modes of the window... Perhaps if you decoded the Lissajous figure that came back to a 2-dimensional detector array....
henkp@nikhefk.UUCP (04/03/87)
In article <2628@phri.UUCP> roy@phri.UUCP (Roy Smith) writes: >In article <15260@onfcanim.UUCP> dave@onfcanim.UUCP (Dave Martindale) writes: -> If you want to get fancy, you can modulate the beam as it leaves ->the laser and put the signal output of the photoreceptor through a bandpass ->filter centered on this frequency (this will mask out incident light); now ->the voice signal will appear as AM modulation on top of the carrier you ->originally used to modulate the beam with. The voice signal appear as phase modulation on modulation frequention of the laser. A "phase multiplier" like mc1496 and a phase shifter to put it in the linear region does the detection job. Henk Peek, ..!seismo!mcvax!nikhefk!henkp.UUCP
mcintyre@rpics.UUCP (04/03/87)
[discussion of laser eavesdropping] Well, this discussion is getting pretty interesting (2d analysis of interference patterns?) but I think that we are all missing something. The fact is that this technology exists, or at least I have been led to believe that it exists by several tv shows I have seen. I have seen several documentaries on the growing ease of invasion of privacy, and all have mentioned and shown the laser eavesdropping at work. The user shines the laser on the window of the room to be bugged. A dot of laser light does illuminate the opposite wall. The listener listens through earphones connected to not very much electronics (it looked like smaller than a shoebox). Maybe the shows were making this up, but they appeared to actually be able to do this, and I am not technically incompetent. There must be an easier way than what has been discussed. -- Dave "mr question " McIntyre seismo!rpics!mcintyre mcintyre@csv.rpi.edu
mae@vygr.UUCP (04/04/87)
Wasn't the U.S. Embassy in Moscow being snooped on a couple of years ago with *microwaves* being bounced off windows? I think some of the embassy staff complained that they felt 'run-down' all the time, which may have been due to large amounts of micowaves(instead of poodle-in-the-uwave-oven, you have grill-the-spooks :-} ). mike - Sun uSystems, MStop 5-40
roy@phri.UUCP (04/04/87)
In article <16143@sun.uucp> mae@sun.UUCP (Mike Ekberg) writes: > Wasn't the U.S. Embassy in Moscow being snooped on a couple of years > ago with *microwaves* being bounced off windows? The story I heard (about as reliable as any Nth-hand info) was that the the Russians presented the American embassy folks with some sort of carved wood plaque of an american bald eagle, or something like that, as a gift. Of course, the embassy folks gave it to the electronics types to look at to make sure it wasn't bugged and then hung it up in the office. It never occured to them that the sheet metal plate on the back of it might actually be a microwave reflector... Memory is hazy, but I seem to remember hearing this 5-7 years ago, and the story was at least a few years old by then. Believe it at your own risk. -- Roy Smith, {allegra,cmcl2,philabs}!phri!roy System Administrator, Public Health Research Institute 455 First Avenue, New York, NY 10016 "you can't spell deoxyribonucleic without unix!"
res@sdiris1.UUCP (04/06/87)
In article <2632@phri.UUCP>, roy@phri.UUCP (Roy Smith) writes: > The story I heard (about as reliable as any Nth-hand info) was that > the the Russians presented the American embassy folks with some sort of > carved wood plaque of an american bald eagle, or something like that, as a > gift. Of course, the embassy folks gave it to the electronics types to > look at to make sure it wasn't bugged and then hung it up in the office. > It never occured to them that the sheet metal plate on the back of it might > actually be a microwave reflector... Memory is hazy, but I seem to > remember hearing this 5-7 years ago, and the story was at least a few years > old by then. Believe it at your own risk. The Bugged Eagle was real, I remember seeing a photo of it in the news. The method involved was that the eagle contained a tuned cavity, with one wall acting as a sound microphone... vibration varied the frequency of the cavity, which radiated for a short distance to a listening post outside the embassy... the bug was powered by a microwave beam at a harmonically related frequency, inducing a signal at the main frequency. -- Skip Sanders : sdcsvax!ucsdhub!jack!man!sdiris1!res Phone : 619-273-8725 (evenings)
larry@kitty.UUCP (04/06/87)
In article <2632@phri.UUCP>, roy@phri.UUCP (Roy Smith) writes: > > Wasn't the U.S. Embassy in Moscow being snooped on a couple of years > > ago with *microwaves* being bounced off windows? It probably still is. The microwave energy is probably being used for at least three purposes: 1. To excite passive tuned-cavity listening devices. A sharply tuned cavity is fitted with a metallic microphone diaphragm. Microwave energy is directed toward the cavity using a directional antenna from the monitoring location. The microwave oscillator is connected to the antenna using a directional coupler having forward and reverse power detectors. The instantaneous VSWR is an indication of diaphragm displacement as the cavity power absorbtion changes through detuning. Modulation of the microwave oscillator, with appropriate detection, can also be used to improve S/N ratio of the detected signal. 2. To excite listening devices which use received energy to power a transmitter on a different frequency, which is then detected by a receiver at the monitoring location. This technique may be implemented by a tuned cavity that is fitted with a varactor diode leading to a second tuned cavity at a higher frequency. The second tuned cavity is fitted with a metallic microphone diaphram. The "retransmitted" frequency is often a simple second or third harmonic of the excitation frequency; depending upon the type of diode and what frequency at which it is designed to oscillate, the retransmitted frequency can also be a small frequency shift of the excitation signal. This principle has been used for a number of years as a passive military radar beacon (sans microphone :-). 3. To measure the micro-displacement of some reflecting metal object in the subject room; this displacement is presumably the result of sound vibration within the room. The reflected signal is modulated both by sound amplitude and sound frequency; the reflected signal is detected as phase modulation and corresponds to the instantaneous velocity of the reflecting surface. This technique has the advantage of no advance "planting" of a listening device in the room. The principle behind this technique has been used for industrial vibration measurement for at least 30 years. > The story I heard (about as reliable as any Nth-hand info) was that > the the Russians presented the American embassy folks with some sort of > carved wood plaque of an american bald eagle, or something like that, as a > gift. Of course, the embassy folks gave it to the electronics types to > look at to make sure it wasn't bugged and then hung it up in the office. > It never occured to them that the sheet metal plate on the back of it might > actually be a microwave reflector... Memory is hazy, but I seem to > remember hearing this 5-7 years ago, and the story was at least a few years > old by then. Believe it at your own risk. It's a true story, and it happened during the 1950's at the United Nations; most people in the know call this "The Great U.N. Seal Caper". :-) It seems that the Russians gave the Secretary General of the U.N. a nice wooden plaque which contained a passive-cavity listening device whose principle I described in (1) above. It operated undetected for at least two years. The frequency of operation was around 330 MHz (which is not truly microwave, but the principle is still the same). The Russians had a high-power transmitter concealed in a truck that they would park in close proximity to the the U.N. building when they wanted to monitor the device. I don't know how much transmitting power was used, but considering the lack of directivity at UHF frequencies I would guess it to be several hundred watts CW. I seem to recall that the device was discovered only because the truck was discovered, thereby triggering a thorough search of the building. You have to admit, them Rooskies have balls. :-) <> Larry Lippman @ Recognition Research Corp., Clarence, New York <> UUCP: {allegra|ames|boulder|decvax|rocksanne|watmath}!sunybcs!kitty!larry <> VOICE: 716/688-1231 {hplabs|ihnp4|mtune|seismo|utzoo}!/ <> FAX: 716/741-9635 {G1,G2,G3 modes} "Have you hugged your cat today?"
roy@phri.UUCP (04/06/87)
In article <1683@kitty.UUCP> larry@kitty.UUCP (Larry Lippman) writes: > In article <2632@phri.UUCP>, roy@phri.UUCP (Roy Smith) writes: > > > Wasn't the U.S. Embassy in Moscow being snooped on a couple of years > > > ago with *microwaves* being bounced off windows? I didn't write that! Larry, you may be an inexhaustible source of useful information about all areas of communications and a cat lover (both good things), but you have to learn to be more careful in quoting! 1/2 :-) > 2. To excite listening devices which use received energy to power a > transmitter on a different frequency, which is then detected by a receiver > at the monitoring location. [...] The "retransmitted" frequency is often a > simple second or third harmonic of the excitation frequency ... This is also, BTW, one of the ways those stolen-item detectors in stores work. The big plastic clips contain some sort of passive tuned circuit, with a diode detector. The gizmos on either side of the door emit RF at some frequency (presumably up in the several hundred Mhz range) and listen for harmonics comming back. The important features of this system are that the replicated parts (the big plastic clips) 1) are cheap to produce, 2) require no internal power, 3) are not likely to break, and 4) can be made physically small. The latter three are properties which also makes this a nice spy technology. -- Roy Smith, {allegra,cmcl2,philabs}!phri!roy System Administrator, Public Health Research Institute 455 First Avenue, New York, NY 10016 "you can't spell deoxyribonucleic without unix!"
ccplumb@watnot.UUCP (04/07/87)
In article <2632@phri.UUCP> roy@phri.UUCP (Roy Smith) writes: > The story I heard (about as reliable as any Nth-hand info) was that >the the Russians presented the American embassy folks with some sort of >carved wood plaque of an american bald eagle, or something like that, as a >gift. Of course, the embassy folks gave it to the electronics types to >look at to make sure it wasn't bugged and then hung it up in the office. >It never occured to them that the sheet metal plate on the back of it might >actually be a microwave reflector... I heard something very similar, except it was a metal box, whose microwave resonance changed as sound waves deformed it. > Memory is hazy, but I seem to >remember hearing this 5-7 years ago, and the story was at least a few years >old by then. Believe it at your own risk. Ditto. -- -Colin Plumb (watmath!watnot!ccplumb) Silly quote: His foot is in his mouth up to his ear.
hal-k@burdvax.UUCP (04/16/87)
> ... the Russians presented the American embassy folks with some sort of > carved wood plaque of an american bald eagle, or something like that, as a > gift... > It never occured to them that the sheet metal plate on the back of it might > actually be a microwave reflector... > > Roy Smith, {allegra,cmcl2,philabs}!phri!roy I remember reading about the same event. As I recall it was a desk ornament that was a resonant microwave cavity. When the microwave energy was sent to it the response was a sound modulated signal of the sounds within the room. These signals were picked up by a ham radio operator in England who reported it to the authorities, eventually leading to the discovery of the device. This goes back 20 or more years ago so don't count on all the details being entirely accurate. Hal Koskela Unisys Corp. Paoli, Pa.
douglas@reed.UUCP (P Douglas Reeder) (04/22/87)
You can listen to florescent lights with a simple photocell. Photodiodes are great for light beam transmitters, especially the new superbright diodes. I've used these myself. I have heard that the new soviet embassy in D.C. is on a hill in a great place for snooping on government windows. Anyone know if laser eavesdropping is really practical from there? -- -Doug Reeder, Reed College
michael@m-net.UUCP (Michael McClary) (04/25/87)
In article <3275@burdvax.PRC.Unisys.COM> hal-k@burdvax.UUCP writes: >> ... the Russians presented the American embassy folks with some sort of >> carved wood plaque of an american bald eagle, or something like that, as a >> gift... >> It never occured to them that the sheet metal plate on the back of it might >> actually be a microwave reflector... > >I remember reading about the same event. As I recall it was a desk ornament >that was a resonant microwave cavity. When the microwave energy was sent to >it the response was a sound modulated signal of the sounds within the room. >These signals were picked up by a ham radio operator in England who reported >it to the authorities, eventually leading to the discovery of the device. Yep (except it was an enormous wooden plaque of the great seal - with a few tiny holes under the eagle's beak to pass the sound to the bug.) Saw an ilustration of the gadget in a newspaper. Looked like this in the side view: H---------------H H ========= H H H H H H H H H H H========================================================= H H H H H H H H=======U=======H The business on the left is a cylinder with the axis up the center of the t-shaped thing in the middle. Think of it as a metal top from an aerosol can (the small type, about as big around as a stack of quarters), with a metal diaphragm stretched over the opening, and a nail with a big head that almost touches the diaphragm. This forms a tuned cavity resonator. The "nailhead" and the diaphragm form a (variable) capacitor that greatly lowers the cavity's resonance, and tunes it back-and-forth slightly as the diaphragm moves. Think of the long horizontal thing as about the size and shape of a thin knitting needle stuck through a hole in the side of the cavity (and insulated where it passes through). The long section forms an antenna, and the T-shaped end couples strongly to the cavity. A good length is a quarter-wavelength for the resonant frequency. (Now shrink the whole thing until you're using a cut-down thimble for the aerosol can lid, and you've got it. I hear they did one that looked like an olive on a toothpick, too, and stuck it in a martini.) If you transmit a carrier a little to one side of the resonance, this thing will reflect it. As the diaphragm moves back-and-forth, tuning the cavity, it will reflect more or less of the carrier, effectively amplitude-modulating it with audio from the room. (Much like slope- detecting an FM signal, but backwards - you modulate the frequency of the filter, not the carrier.) =========================================================================== "I've got code in my node." | UUCP: ...!ihnp4!itivax!node!michael | AUDIO: (313) 973-8787 Michael McClary | SNAIL: 2091 Chalmers, Ann Arbor MI 48104 --------------------------------------------------------------------------- Above opinions are the official position of McClary Associates. Customers may have opinions of their own, which are given all the attention paid for. ===========================================================================