Re: Active loop antenna overload

2001-09-24 Thread Robert Macy
Move the antenna further away. then use correction factors to calculate what it would have been at the original distance. Magnetic fields decrease as the inverse cube of the distance. So just apply a correction factor to "boost" the amplitude back up. For example, twice the distance away means

Need electrical characteristics of epidermis (skin)

2001-09-14 Thread Robert Macy
Sorry to post here but am running into a brick wall at trying to find out something as simple as the resistivity and dielectric constant for skin! Does anybody have a source? Need quick, please. - Robert - --- This message is from

Re: Noise from flourescent light ballasts?

2001-09-06 Thread Robert Macy
Chris, Fluorescent tubes are noisy anyway, but the old passive ballasts are starting to be replaced with active "electronic" ballasts. Those electronic widgets actually run at frequencies down near what you're using. Electrically they can be EXTREMELY noisy. The US has no real restrictions. A

Re: 120V appliance on 240V supply

2001-05-14 Thread Robert Macy
They will deliver less powerabour 50/60 of what you expect. The power supplies in those ovens are quite inexpensive and use a single rectifying diode. When the voltage gets high enough, the microwave bursts on for a short time. Thus, if operated from 50 Hz instead of 60 Hz, the power will d

Re: Zo

2001-02-01 Thread Robert Macy
Did you find out what you need? Somewhere around here I have the equations that closely approximate twisted pair for 26 Awg and 28 Awg wire from DC to 10MHz. They were derived from empirical modeling. You can make various approximations to simplify their use. That includes impedance, loss per

Re: Re[2]: assist me

2001-01-03 Thread Robert Macy
The accurate volume is about 1/3 by 1/3 of the outside dimensions. At least that's my "measured" experience. Just means one has to make a rather large Helmholtz for a large sensing coil. And my recollection of most sensing coils in that range are that they're over 1/2 meter in diameter. I've s

Re: Leakage Current Measurements

2000-10-04 Thread Robert Macy
Actually, most meters average the waveform, then apply a rote formula converting that average to an rms reading which is more likely to err on the side of too low a reading. For a square wave it will read too high by 6% (actually worked this out, but forgot the actual number, but you have the ide

Re: Probing power plane with analyser.

2000-09-28 Thread Robert Macy
We made a probe using rigid coax with its built in SMA connector. Solder a pin to the side of the coax and file it diagonally to create a sharp point. To increase the loading impedance we used an SMA "collar" that had been filed out to place a series chip resistor of 470 ohms in series with the c

Re: Argentina IRAM

2000-09-22 Thread Robert Macy
Uh, isn't the national language of Argentina Spanish? Not Portuguese. The web sites may still not be helpful, but at least aren't they in Spanish? - Robert - -Original Message- From: George Sparacino To: emc-p...@ieee.org Date: Friday, Septem

Need Test Lab set up to test for ETS 300 342-1 (Mobile phone ancillary equipment)

2000-09-14 Thread Robert Macy
Does anyone know labs set up to measure mobile phone ancillary equipment? located in northern California area? Specifically Silicon Valley, San Jose area. Just need to test for radiated susceptibility at 3 V/m of a hands free headset equipment when attached to a cell phone. Yes, any chamber can

Re: Electrical safety of firearms

2000-07-28 Thread Robert Macy
Guessing the best place to look would be in the "electronic detonator" requirements. They must have some really stringent compliance requirements to prevent mishaps. - Robert - -Original Message- From: pgodf...@icomply.com To: emc-p...@majordomo.ieee.org List-Post:

Re: ism band phones

2000-07-22 Thread Robert Macy
Ron, Interferernece? You need to find out about the specs for others then. That frequency band is allocated for microwave ovens, which obviously have lots of power. Watch out in a metropolitan area around lunch time when all the restaruant and office microwaves start operating, you'll see lots

Re: Are NTCs Safe to Use in Electrical Equipment-short life of light bulbs

2000-07-10 Thread Robert Macy
The subject of short life of light bulbs appears often on the alt.home.repairnewsgroup. People come up with potential sources of problems like "on the same branch with the sump pump(or well pump)", and "long lines to the light bulb". Their solutions were to put in those dimmer switches that c

Re: Global Engineering Change Process

2000-05-27 Thread Robert Macy
Many things to cover: Mechanism for approval process over a distributed area. Coordination of notification over a distributed area. Is this a true ECN, or do you still need approvals? If you need approvals, you might end up getting a change to your "ECN" Therefore, you'll need to split the pro

Re: Heat sink temperature rise

2000-05-13 Thread Robert Macy
Just my two cents worth with regard to temperature: It is my understanding that for every 10C rise the life of the part is half what it would have been. - Robert - Robert A. Macy, PEm...@california.com 408 286 3985 fx 408 297 9121

Re: Stroboscopic light sources

2000-03-29 Thread Robert Macy
Not sure where to look. But it is my understanding that the frequency of an impulse stimuli can "lock" a person's alpha brain wave inducing trance-like states. Guess at around the 5Hz to 10Hz range. In particularly susceptible people, certain pulsating frequencies can induce epileptic seizures.

Re: StripLine

2000-03-29 Thread Robert Macy
I've got a copy of DimStrip which calculates their characteristics. Either electrical properties from dimensions, or dimensions from required electrical characteristics for stripline, or microstrip. Runs under DOS and also has adjacent line capability. Is there a place I can post it so people c

Re: modest proposal

2000-03-27 Thread Robert Macy
As long as language is an art form, having all of its nuances explored, being legitimized by its users; it is highly unlikely that anyone will successfully create a viable alternative. - Robert - -Original Message- From: Muriel Bittencourt de L

Fw: Dithered clocks and EMC - BEWARE

2000-03-17 Thread Robert Macy
Of interest, so I forward this to the group: - Robert - Robert A. Macy, PEm...@california.com 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 619 North First St, San Jose, CA 95112 -Original Message--

Re: EMC and product safety split?

2000-03-13 Thread Robert Macy
Ditto, robertm...@aol.com -Original Message- From: Davis, Mike To: 'cdup...@cs.com' ; rl...@tectrol.com ; emc-p...@ieee.org List-Post: emc-pstc@listserv.ieee.org Date: Monday, March 13, 2000 8:38 AM Subject: RE: EMC and product safety split? > >I concur with the comments from K. Ric

Re: Horn Antenna

2000-03-06 Thread Robert Macy
Derek, The horn antenna is an impedance matching device for getting between 50 ohm lines and 377 ohm free space while launching TEM mode wave fronts. You could use the commercially available one which has an awful antenna factor. It's broadband as a result of the ribs placed in the horn. Just

Re: Debugging EN61000-4-2 Techniques

2000-03-06 Thread Robert Macy
Keith, Without looking at the specifics. Disruption from a discharge can be caused by direct high voltage gradients, localized breakdown which then applies direct high voltage, and the often forgotten current injection where the discharge makes enough current flow that the flow induces a voltage

Re: Fwd:Re: UL 891

2000-03-03 Thread Robert Macy
Wouldn't BABT have such a facility, too? - Robert - -Original Message- From: Jim Bacher To: emc-p...@ieee.org List-Post: emc-pstc@listserv.ieee.org Date: Thursday, March 02, 2000 3:51 PM Subject: Fwd:Re: UL 891 > >forwarded for Chris Dupres.. Jim > > >__

Re: Searching for a Design for EMC email list

2000-03-01 Thread Robert Macy
Jose, I've seen software go by on sci.engr.electrical.compliance newsgroup. I think more depth is discussed here than there, though. You might take a look at Douglas Smith's web site www.dsmith.org Or Charles Grasso's web site: http://www.ewh.ieee.

Re: conducted emissions test setup

2000-02-24 Thread Robert Macy
ation in measurements in this range than one would otherwise expect, especially if the peak is just starting near 30MHz. -----Original Message- From: Gert Gremmen To: Robert Macy ; Muriel Bittencourt de Liz ; Lista de EMC da IEEE List-Post: emc-pstc@listserv.ieee.org Date: Wednesday, February 2

Re: conducted emissions test setup

2000-02-23 Thread Robert Macy
Gert, The connection (Wire A) the ground connection from the EUT to the ground plane is indeed quite long and inductive and "does not exist" However, the three wires HOT, Neutral, and GND form a 3 winding transformer which has a core impedance in the range of 7uH for a six foot length of Belden

Re: conducted emissions test setup

2000-02-23 Thread Robert Macy
Muriel, Without a ground plane you will not have the necessary "parasitic" capacitance to the body of your EUT. It is this third path that often causes failures up passed 1 MHz. Definitely if you do your test in a "proper" setup versus a chamber you will see differences in the 20MHz to 30MHz ra

ASDL Modems & FCC Part 68

2000-01-26 Thread Robert Macy
Do SDL modems need to meet all the part 68 specs? Or can they violate just a little (and where) and obtain a waiver, but still be certified? - Robert - - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord..

Re: Magnetic field immunity in the Arctic regions

2000-01-25 Thread Robert Macy
ot;Quiet Room" specs to be used for mapping electrical brain activity. And those specs are going to make a chamber look like a sieve. -Original Message- From: Robert Tims (EMX) To: 'Robert Macy' List-Post: emc-pstc@listserv.ieee.org Date: Tuesday, January 25, 2000 9:40 AM S

Re: Magnetic field immunity in the Arctic regions

2000-01-25 Thread Robert Macy
Don't need SQUIDs to read earth's field. Fluxgates have enough accuracy. And the earth's natural noise floor is well above the SQUID so you don't need to pay for all that extra. Remember, SQUIDs can observe the current flow as metal rusts. Check out Geometrics. They use the decay of the electro

Re: Magnetic field immunity in the Arctic regions

2000-01-25 Thread Robert Macy
Are fields stronger there? The geologic survey people should have those numbers. In California the fields are about 50microT which is pretty insignificant. If you took a loop of wire that was 1 sq meter area and "flopped" it over in the earth's field you'd have to do it within half a second even

Re: E-Field Probe Question

2000-01-25 Thread Robert Macy
At first that looked like what is asked for is the ability to pass signals with a bandwidth of 10Hz. Given what they're looking for, stating frequency would make it easier to understand. But isn't the risetime 1/2pi F?? Or, are they just saying that the readings pop out at least 10 times per se

Re: EMC Circuit Board Design

2000-01-24 Thread Robert Macy
radiators. - Robert - -Original Message- From: cetest To: Robert Macy ; rehel...@mmm.com ; emc-p...@majordomo.ieee.org List-Post: emc-pstc@listserv.ieee.org Date: Monday, January 24, 2000 12:34 PM Subject: RE: EMC Circuit Board Design >Very good contribution R

Re: EMC Circuit Board Design

2000-01-23 Thread Robert Macy
Here are a set of rules worth recommending: Engineering design checks: 1 Avoid "spaghetti logic" block diagram. Make certain there's a good flow of functionality across and around the PCB. This includes using the concept of transferring INFORMATION not ENERGY (except where one must, like with

Re: Lead Banned in Europe & Japan?

2000-01-19 Thread Robert Macy
Just my $.02 worth It seems the problem is that willy-nilly use of lead in products leads to the undesirable effect of lead migrating into the environment. However, lead acid batteries are not banned, because there is strict recycling. Hmmm put those two together and the problem is solved.

Re: EN 61000-4-2

2000-01-18 Thread Robert Macy
Yes, we were applying the discharges too rapidly. Faster than 1 per 10 seconds did not allow adequate discharge. faster than 1 per 60 seconds still did not allow adequate discharge. So that's 10 minutes a discharge pointand still the test was not adequate for the intent of the test.

Re: EN 61000-4-2

2000-01-18 Thread Robert Macy
True. Same experience. To "legitimize" the test we had to "discharge" the case/structure between discharges. Or, to really aggravate the test, we went from - to + to - to + which often caused a failure. But the point to test at all voltage levels is well made. The discharge wavefront (and att

Re: Luminaire Ballast

2000-01-13 Thread Robert Macy
My opinion based upon working with 20KV, 200KV: You need to have the outer shroud rated for 4KV also. First, suppose the lamp doesn't strike? Then the 4KV is there a long time. Second, insulation is a "tricky" thing. Its ability to hold off voltage doesn't add, unless the materials are *very*

Re: Y3K

2000-01-12 Thread Robert Macy
In my notes from university (when cps was prevalent) I see that originally kcps was written and even mcps (handwriting was terrible hard to tell whether the m was capital or not, the m for millivolts was always written mV), then when the change to Hertz came about (that probably should be hertz) a

Re: transient suppression

2000-01-12 Thread Robert Macy
Ken, Rule of thumb which hopefully is accurate: MOV's have a discrete lifetime (like 10 cycles at full rating) before they're gone. In order of joules absorbed versus package size: Glass tubes, MOV's, silicon (from huskiest to weakest) For turn on time: silicon, MOV's, glass tubes (from fastes

Re: Radiation levels.

2000-01-11 Thread Robert Macy
David, Measured 3 to 7 V/m around and inside a building that is within 200-300 feet of the 10KW AM station's three towers. The towers are phased and the amplitude you measure will change based upon time of day as the station changes that phasing. Amplitude is greatly affected by materials, meta

What is "Fire-wire"?

2000-01-11 Thread Robert Macy
Heard of this high speed interface? Anybody know about it? Need information, please. Something about IEEE1394 Is the cable defined *very* well? like CAT-5? - Robert - - This message is coming from the emc-pstc discussion list. To cancel your subscription, send

Re: Common Mode or Differential Mode

2000-01-04 Thread Robert Macy
Generally, low frequency is dominated by differential mode caused by the current demand of the switcher being imprinted across the impedances of the components; then in the midrange its anybody's guess, but usually common mode, because the capacitors and series impedance elements start to take eff

Re: Network efficiency

1999-12-29 Thread Robert Macy
There is a way to do this. *IF* you really want quantitative answers, you can go through a laborious process (but kinda fun, too) of characterizing each step of your system's block diagram and the impact you find along the signal path. You have to start "microscopic" then get to the "macroscopic

Re: 50 GHz EMC testing

1999-12-15 Thread Robert Macy
Well, in no particular order there's Elliott Labs in Mtn View Compliance Certification Services in Morgan Hill (possibly Sunnyvale, too) I'm pretty sure that these can do it too: Intertek in Redwood City Electronic Compliance Labs in Sunol (or is that Sunnyvale) EMCE in Fremont

Re: Cell Phone Hazards?

1999-12-08 Thread Robert Macy
I'll ask our county supervisors (they occupy this building, too) - Robert - -Original Message- From: Bailin Ma To: 'Robert Macy' ; Edward Fitzgerald List-Post: emc-pstc@listserv.ieee.org Date: Wednesday, December 08, 1999 9:01 AM Subject: RE: Cell Phone Ha

Re: Warning Label Overkill

1999-12-06 Thread Robert Macy
Also, filling liquid to very close to the top prevents the bottle from storing as much energy. - Robert - Coca Cola used to lose glass bottles until they reduced the air at the top. -Original Message- From: Mark To: emc-p...@ieee.org List-Post: emc-pstc@listserv.ieee.o

Re: warning label overkill?

1999-12-06 Thread Robert Macy
You were then extremely lucky that pieces of the wire did not lacerate your eye. - Robert - -Original Message- From: Antonio Sarolic To: emc-p...@majordomo.ieee.org ; Robert Macy Cc: Antonio List-Post: emc-pstc@listserv.ieee.org Date: Monday, December 06, 1999 12

Re: warning label overkill?

1999-12-05 Thread Robert Macy
Isn't there a little wire basket that keeps the cork in? Once that's removed, it's essentially an armed explosive device. I've been at parties where people removed the wire retainers and left the bottles sitting in the ice, supposedly to make it easier to have their corks removed later. Our hos

Re: Cell Phone Hazards?

1999-12-04 Thread Robert Macy
Has anybody calculated the skin depth that 900MHz has in the human body? Is it shallow enough to make it impossible to do anything at the depth the tumors reportedly occur? - Robert - -Original Message- From: Patrick, Al To: 'Martin Green' ; Patrick, Al ;

Re: Cell Phone Hazards?

1999-12-04 Thread Robert Macy
Near our building near downtown San Jose, in what are called "the county buildings", one county building wing had 15 cases of very rare form of brain tumors. The incidence of a single case is very rare but to have so many in one building and only in one wing of that building is statistically incr

Re: Article to UL

1999-11-29 Thread Robert Macy
The timing of the article seems to coincide with tests done on a major automotive maker's products. What better way to discount the negative publicity this will cause than to discredit the source? Just food for thought. Especially, as many claim the article was more emotional than factual.

Re: A-t/m vs A-t/cm

1999-11-23 Thread Robert Macy
The tricky part is making sure that the conversion is the right direction. 1 A/m = 0.01 A/cm If you have oersteds and want amperes per meter, multiply by 79.577 If you have amperes per meter and want oersteds, multiply by 0.01257 - Robert -

Re: Floating Circuits - Protection Against Electric Shock

1999-11-18 Thread Robert Macy
Is this article in *.pdf format for any to pick up? - Robert - -Original Message- From: John Juhasz To: emc-p...@majordomo.ieee.org ; 'ri...@ieee.org' Date: Thursday, November 18, 1999 12:09 PM Subject: Floating Circuits - Protection Against Electric Shock

Re: Printed Wiring Board Design for Safety Compliance

1999-11-18 Thread Robert Macy
Good question. Have you posted tosci.electronics.cad group to see what their answers were? - Robert - -Original Message- From: Rains,Mike To: 'emc-p...@ieee.org' List-Post: emc-pstc@listserv.ieee.org Date: Wednesday, November 17, 1999 2:07 PM Subject:

Re: DC Power Applied to an AC Rated Switching Power Supply

1999-11-17 Thread Robert Macy
BE CAREFUL ! ! ! If this PS does not have Power Factor Correction Many switching power supplies comply with the conducted emissions limits BECAUSE of the conducting angle of the AC diodes. Simply said, the AC rectifying diodes only come on for 15--18% of the duty cycle. therefore the noise de

Re: Conducted Emissions for PS output

1999-11-17 Thread Robert Macy
Don't know about a formal spec for this one, but the general "rule of thumb" for low frequency conducted is less than 1% of the regulated value. For example, less than 5mV peak to peak from the 5 Vdc, less than 12mVpp from the 12Vdc, etc. Typically, the supplies put out half those values. If yo

Re: Grounding Questions

1999-11-17 Thread Robert Macy
re can one do, but install it oneself?) - Robert - -Original Message- From: Matthew Meehan To: Robert Macy ; emc-p...@ieee.org List-Post: emc-pstc@listserv.ieee.org Date: Tuesday, November 16, 1999 10:49 PM Subject: Re: Grounding Questions >Robert, >I don&

Re: Shielded Enclosure Fire Hazard

1999-11-17 Thread Robert Macy
Great, now all you need are some holes poked in the chamber. - Robert - -Original Message- From: Price, Ed To: 'emc-p...@ieee.org' List-Post: emc-pstc@listserv.ieee.org Date: Tuesday, November 16, 1999 7:36 PM Subject: Shielded Enclosure Fire Hazard > >Hi Listmembers! > >

Re: 60 Hz Power Line Impedance

1999-11-16 Thread Robert Macy
s in advance. > >Bob Martin, PE, NCE > >Sr. Technical Manager >Intertek Testing Services >(978)263-2662 >fax(978)263-7086 >r...@itsqs.com > >The opinions expressed are my own and not necessarily those of my >employer. > > >-Original Message- >From

Re: Grounding Questions

1999-11-16 Thread Robert Macy
Why has no one mentioned using a GFI detector as a "failsafe" way to make certain the installation is done per spec? After all, in the US the manufacturer still comes out liable for any damages. - Robert - -Original Message- From: Crabb, John To: '

Re: 60 Hz Power Line Impedance

1999-11-16 Thread Robert Macy
For our building we used a 1500W glowing (resistive impedance load) heater. Measure before, then turn on measure after and calculate the impedance. Also measure adjacent branches to get a feel for how much impedance was in the branch and how much was at the transformer and drop. This is more accu

Re: hot-swap disc drives

1999-11-11 Thread Robert Macy
Hi, Hans, Are you thinking of Four Phase ?? Weren't they a competitor to Tandem Computers? Don't know who did the first "hot swap" disk drives. Patent search tell you? Remember at one time it was really important to be able to pull out a hard drive and secure it away in a safe someplace. Boy

Re: EMC and Safety of equipment used in aircraft

1999-11-10 Thread Robert Macy
Take a look at Radio Technical Commission for Aeronautics (RTCA) Document No. DO-160B, "Environmental Conditions and Test Procedures for Airborne Equipment" The copy I have is dated July 20, 1984 Wow time flies! The cover page is ISO 7137 if that's any help. Basically, RTCA/DO-160 is ab

Re: Conductive Coating

1999-11-04 Thread Robert Macy
A small pedantic point here: Coatings are usually rated in "ohms per square" which is dimensionless. Looking at the resistance formula: R = rho * length / Area = rho * length / ( width * thickness ) Given fixed rho and fixed thickness (of the coating) you can see that you're left

Re: Device Specifications

1999-10-14 Thread Robert Macy
Insertion loss measured in a 50 ohm system could give you misleading performance expectations in your real world applications. For example, free space impedance is 377 ohms, knowing the impedance of the bead will tell you how much attenuation to expect.Or, many sources, like those from the PC

Re: Conduit entry dimensions

1999-10-13 Thread Robert Macy
>>Anaconda Sealtite is 12.6mm I/D, 17.8mm O/D; Mark, thanks for the details, but are you certain about that 17.8mm diam? Seems like that would really interfere with most holes. - Robert - -Original Message- From: Mark To: emc-p...@ieee.org List-Post: emc-pstc@list

Re: EMI from nearby welding

1999-10-13 Thread Robert Macy
First, look at voltages induced by the magnetic fields: The magnetic field from a single infinite long cable is: u * I whereu = 4pi10-7 B = S is in meters 2 * pi * S I know you don't have

Re: Coatings for Ferrite Tiles? (Magnetic Wallpaper)

1999-10-07 Thread Robert Macy
Thanks for the details. Just in case you "accidentally" permanently affect your monitor ( like I did after playing with one of those really strong space magnets); use a cheap electric pencil sharpener to degauss your screen's metal mask when the power-on degausser isn't strong enough. You're rig

Re: Inductor

1999-10-07 Thread Robert Macy
I've got some toroids sitting on the bench (about 2 inches in diameter) that would accomodate that with around 20 turns of doubled up 12 Awg wire. You need them? - Robert - -Original Message- From: Derek Walton To: emc-p...@ieee.

Re: Coatings for Ferrite Tiles?

1999-10-01 Thread Robert Macy
Light colored, self adhesive shelf liner? - Robert - -Original Message- From: WOODS, RICHARD To: 'emc-p...@ieee.org' List-Post: emc-pstc@listserv.ieee.org Date: Friday, October 01, 1999 3:44 PM Subject: RE: Coatings for Ferrite Tiles? > >We have been consi

Re: Magnetic Field Testing

1999-10-01 Thread Robert Macy
Deflect 2 degrees? Hmmm. The earth's magnetic field is around 50uT. To deflect the compass 2 degrees would take 1.7uT at a right angle, right? Therefore, you could set a level of 1 uT "residual" magnetism for your testing requirement and have some margin. With that quantized number, you could

Re: Bonding Meter

1999-09-24 Thread Robert Macy
That pretty much takes a four point measurement. However, if you're after only reading "about" the right value, or side by side comparisons of the esr of a cap, try Dick Smith's esr meter. Less than $60 in kit form from Australia. Is easy to put together and extremely functional for measuring t

Re: spectrum analyzer/receiver for pre-compiance and diagnostic testing

1999-09-17 Thread Robert Macy
You can use the HP 141T (storage scope mainframe) and the analyzer plugins: The 8552 IF section, 8553 (low frequency analyzer), 8554 (up to 1GHz), and/or 8555 (way up there) Some of these systems have been floating around for less than $1500, can't get much cheaper if you want "qantitative" data.

Re: Resistors across Reinforced Insulation

1999-09-17 Thread Robert Macy
Hmm... 5 mA 3000V that's a small 15 Watts. Ethernet coax uses a high voltage cap in parallel with multiple resistors. - Robert - -Original Message- From: Jim Eichner To: 'EMC-PSTC - forum' Cc: Tom Unger List-Post: emc-pstc@listserv.ieee.org Date:

Re: Sweeping components and filters

1999-09-16 Thread Robert Macy
sound card (also have a Turtle Beach Fiji with >better S/N ratio) to generate a sweep and track/display the response. >The >only down-side to this is that you need to pad the output and input >ports >with 50 ohms (to duplicate the way OTHER filters are almost always >tested

Re: Sweeping components and filters

1999-09-13 Thread Robert Macy
I use that HP Network analyzer that goes to 500MHz. On a component by component basis. Then shove that all into a PSpice circuit which allows me to add parasitics, etc. Then I can play games with waveforms, risetimes, components, etc and pretty much predict what the filter will do. Sometimes a

Re: Amplifier for measurements above 1GHz

1999-08-26 Thread Robert Macy
My experience with the HP spectrum anaylyzers is that it has about 35dB NF. You can calculate this from observation *and* from their data sheets. So if you want the analyzer to not contribute, you need a lot of gain in front. I'd recommend two stage amplifiers. Plus, you really have to make cer

Re: Concrete as an insulator???

1999-08-21 Thread Robert Macy
Not sure, but check into Light Rail. They use 600Vac (I believe) and use the natural insulating qualities of concrete (where the rails are placed) to give fairly good isolation from ground. >From memory - the rails are the return terminal. - Robert - - > >Hello

Re: PC Power Supply w/ PFC

1999-08-18 Thread Robert Macy
Try Digital Power Corp in Fremont, CA 510 657 2635 or their VP Mktg: bh...@digipwr.com - Robert - > >We are looking for a supplier of 300 Watt PS2, PC power supplies that have PFC >(Power Correction Factor). >Here is the spec: > >It mus

Re: NSA

1999-07-29 Thread robert Macy
Have you checked the resonance size of your ground plane? Or, multiple resonance size? Perhaps, the area where the turntable sits just aggravates all this. - Robert - On Thu, 29 Jul 1999, WOODS, RICHARD wrote: > > Thanks for all the comments. Some ha

Re: Test site threatened

1999-05-05 Thread Robert Macy
Wow. Load the City Council meeting with as many people as you can get. Even if they're only mildly interested in the issue. Have them look like all the people are of like mind. Unfortunately, the parallel here is like a person with a very nice view of the ocean (beach valley river etc) and has

RE: Precompliance Testing

1999-05-04 Thread Robert Macy
Absolutely, *PLUS* you pick up the advantage of natural shielding (the ground plane) between you and the R&D going on down below. - Robert - On Mon, 3 May 1999, Gary McInturff wrote: > I'll agree with Brent, and others, the headaches of a metal room or the

Re: Harmonics

1999-04-24 Thread Robert Macy
t two different sides of the same elephant? > > Ed > > > > From: Jeff Chambers > Subject: Re: Harmonics > Date: Fri, 23 Apr 1999 19:41:52 +0100 > To: Gary McInturff , "'ed.pr...@cubic.com'" > , Robert Macy , Scott Do

Re: RE Harmonics

1999-04-23 Thread Robert Macy
s non-repeating > signal. In Robert Macy example of a 25% duty cycle perfect square wave not > containing a fourth harmonic is just a twice the fundamental square wave. If > you apply the Fourier series math are a Fast Fourier Transform, FFT, on his > illustration, the fundamental frequ

Re: Harmonics

1999-04-22 Thread Robert Macy
OOPS! On Wed, 21 Apr 1999, Robert Macy wrote: > Can't make a general statement. A "perfect" square wave of 50% duty > cycle is missing all the even harmonics. A "perfect" 25% duty cycle is > missing every harmonic that's a m

Re: RE Harmonics

1999-04-22 Thread Robert Macy
>The amount of harmonic content in a waveform is weather it is an even or odd or somewhere in between function. A triangle waveform has all harmonics decreasing in a 1/N function. A square waveform has harmonics decreasing in a 1/(N*N) function. A perfect square wave (centered around zero value

Re: Harmonics

1999-04-22 Thread Robert Macy
>The question is numbering of harmonics. >One side says that given a fundamental frequency of 200 MHz, the first harmonic is 400 MHz, the second harmonic is 600 MHz and the third harmonic is 800 MHz. >The other side says that given a fundamental frequency of 200 MHz, the first harmonic is 200 MHz

Efficacy/cost value of used EMC Chambers

1999-04-20 Thread Robert Macy
Anybody know what it takes to use a 15 year old chamber and whip it into shape for maximum certification capability (3 m range only)? We're talking modular chamber with glued on cones to be dismantled and reassembled (no doubt all the old cones will be lost) Has anyone done this?

Re: Noise Figure

1999-04-13 Thread Robert Macy
>I am trying to determine the maximum noise figure that I can have for my 1-16.5 GHz EMC receiver system which includes the horn, mixer for above 18 GHz, preamp, cable and spectrum analyzer. I know the following: * Signal level received by the horn * Gain through the system * No

WTB: RF Chamber suitable for 3m test of rack mount size

1999-04-08 Thread Robert Macy
Anybody out there have a chamber for sale? Need at least 3m testing of a small refrigerator size. - Robert - - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubs

RE: EMC for automation & control - Electricity utilities (UNIPEDE )

1999-03-31 Thread Robert Macy
IMHO the magnetic fields go right through the watch case and either disrupt what's going on or can even magnetize the parts. Either way, the parts are like "stuck" together and the watch won't run well. Also, my father could never wear a watch, a great gift watch always would stop. The same watch

Re: Xenon Short Arc Lamp, Theatre Movie Projector, EMC Issues?

1999-03-20 Thread Robert Macy
Two issues of emc will hit you. 1) the trigger for the arc This one is a pulse that is used to "fire" the arc. Usually, 20-30KV spikes that hit once a second until an arc generation is detected. The noise from these can be quite impressive, but at least they're not that broadband. 2) the stan

Re: Wanted Dead or Alive: LOW COST Antenna Mast and T/T -- Reward

1998-12-18 Thread Robert Macy
If you have time, you can make the turntable (assuming light load) from a drain pipe pvc (large diameter) which is attached to an antenna rotor (those used in people's homes who live in fringe area). The thing was all strapped and glued which had to be inexpensive. Although uncalibrated position

Re: MPRII, TCO95 or 99, Egronomics

1998-11-19 Thread Robert Macy
I've got copies of the MPRII rules. They'd have to be out of date by now, (circa 1990) but at least it's good reading. I should have the origin of the MPRII printouts somewhere, but not off the top of my head. If you strike out, give me a call: Robert Macy

Equivalent radiators

1998-11-18 Thread Robert Macy
What is equivalent to : a 4 inch long wire excited at one end with 3 Vpp at 100MHz a 4 inch long slot with swirling current of how much to be equivalent radiators? - Robert - PS My guess was 10-100mA, but I would like to get a true qualitative answer.

RE: ANSI C63.4

1998-11-13 Thread Robert Macy
The ferrites "remove" the cable from the fields to some degree. No matter how perfect the baluns are the cable still represents a conductor out in the middle fo the fields you're working with. - Robert - On Thu, 12 Nov 1998, WOODS, RICHARD wrote: > Hans,

Re: Heat Warning

1998-10-28 Thread Robert Macy
If this temperature is the absolute value, not much of a problem. But if this is the "rise above ambient", big problem. That means you get about 24C rise and if that's operated in a hot office space like at 35C then thee base plate gets *very* hot. Once in our non-airconditioned office on a

Re: EMI Limit Margin Summary

1998-10-27 Thread Robert Macy
Sorry, to not get this in before your summary. When Sony (video div) was my client, they had an internal spec margin requirement of 8 dB. That's right! 8 dB below Class B limits. After going though that I'm convinced to use Sony equipment as support electronics.

Re: Required Margin for EMI?

1998-10-26 Thread Robert Macy
It is my understanding that this margin is a carryover from VDE requirements where for statistical reasons you need 2.2 (?) dB margin in order to infer that from a single unit test, your other units will also comply. It is also my understanding that that margin was waived when 3-8 units were test

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