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Re: yep w_tom is still full of CRAP !!!!



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You see w_tom, its not worth my time doing a research paper for you,
becuase you fail to respond to whats posted. Instead you steer away
from the topic.

BTW: When I was at uni, I learned how to gather information and
publish it. However, 90% of what I did I never really understood until
I actaully put it into practice.


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LOL, you are using defence lawer tactics now, citing lies. Where was I
critical of the paper? I made note to your 1960 references, which
suggests to me that you do not understand modern telco design. Thats
being critical of you, not the paper.

<snip>

If you would like to make yourself credible, then please respond to
what I posted.




Re: yep w_tom is still full of CRAP !!!!



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Well Actually Andy he is citing more lies than you think you see and let me
quote from w_tom directly here :

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Now unfortunately for w_tom there is a listing of the Bell System Technical
Journal publications and Articles available at:
http://www.reference.com/browse/wiki/BSTJ_papers

and while this listing is not complete all the 1960 issues are there, and it
is pretty clear that the Bell System Technical Journal was not published in
October of 1960 !
The Bell System Technical Journal was published every Second month in 1960
with Volume 39 Issue 5 published in September of 1960 and Volume 39 Issue 6
published in November 1960 !
None of the Articles listed for 1960 were written by Bodel or Gresh

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He is not credible as he is a Liar and he cannot respond to Direct postings
this is why he carefully guards his anonymity.

Best Regards (to Andy and other Lurkers)
Richard Freeman




Re: yep w_tom is still full of CRAP !!!!




Note gentle reader that as per usual w_tom cannot quote my message in its
entirety but snips and misquotes to make an erronous point.

First I can recycle all these points because w_tom has not really answered
them (please feel free to skip past this section if you have read all this
before):


w_tom claims that a MOV based surge arrestor can provide 100% effective
protection.
Unfortunately there is not a MOV manufactured that can safely handle 1% of a
typical Direct Lightning strike - w_tom avoids posting links to Data sheets
for MOVs because he knows that I could point out that any MOV he could find
would have difficulty handling a near strike let alone a Direct strike.

w_tom claims that it is all in the Earthing....
Ironically w_tom actually speaks some truth here but what he neglects to
mention is that a single Earth stake will suffer an EPR (Earth Potential
Rise - I believe that in the USA this is known as GPR) of in excess of
100,000 Volts in a direct strike.
w_tom does not even understand the basic physics involved for Earthing -
this is why he so frequently refers to the 'Art of Earthing' because for
w_tom Earthing is an art not a science.
An Earth required to even begin to effectively shunt a Lightning strike with
a minimum EPR requires multiple Earth stakes bonded together with low
impedance cable/bussbars covering 1/4 of an Acre or more - is this practical
or cost effective in a Domestic situation ? nope ! - yet w_tom still claims
100% effective 'whole house protection' for domestic premises is not only
possible but inexpensive.

w_tom claims that Lightning does not come in via Phone lines as all Phone
lines in North America are adequately protected - this is another of his
100% Bullshit claims he then tries to squirm out and blame the home owner
when presented with evidence that a high number of injuries and some deaths
occour each year in North America due to folk using Telephones during
Thunderstorms.
Further more w_tom claims that Telephone exchanges never ever suffer
lightning damage - this in direct contradiction of the experience of anyone
who works in the Telecommunications industry. w_tom ignores the example
provided as an inconvenient Fact.

Next w_tom claims that MOVs have been adequate protection for Telephone
exchanges since the 1960's - he neglects to mention that the Exchange
Technology in the 1960's was mainly Relay based switching with a lot of
Step-by-step (and Strowger) equipment still in use. whereas modern exchanges
are primarily digital Micro-processor based and these Micro-processors
running at up to 200Mhz routinely deal with Signals lasting just nano
seconds. The VLSI integrated circuits used in these Exchanges are
susceptible to static charges so small that a careless Tech who is not using
antistatic precautions when handling the Circuit boards in the exchange can
cause damage without even feeling or noticing the discharge.
w_tom from his standpoint of complete and utter ignorance then asks how
Spikes from Lightning lasting mere nano-seconds could not possibly cause
damage.

Further more modern exchange equipment does not depend on MOVs for
protection as while they may have been adequate to protect Strowger switches
they are neither up to the task nor reliable enough to provide protection
for modern exchange equipment so w_toms claim that lack of damage to
Telephones proves the effectiveness of MOV Lightning protection is also
proved False.
Modern Exchanges equipment typically uses an impedance of some sort in
series with the line to limit the current to managable levels then typically
a Transzorb or equivalent (Transzorb is a registered Trade name of Vishay
semiconductor however the term is often used to refer in a generic manner to
clamping diodes used for spike supression) to clamp the surge. This though
is not a techniique that can be readily adapted for use on low imedance
circuits like the AC power mains.

Next w_tom claims that a decently sized MOV does not suffer degredation -
again he provides no links to such a MOV's data sheet because all MOVs
suffer degredation when they suffer from surges - especially surges outside
the MOVs stated limits. But again w_tom knows that I can show that any MOV
that he posts a link to the data sheet for will suffer degredation and
possibly destruction in the event of a direct strike (and even in the event
of many near strikes) so he carefully avoids this inconvenient Fact *.

w_tom also claims that degredation of a MOV does not lead to it's clamp
voltage changing and the MOV becoming leaky - which leads to thermal runaway
in the MOV and ultimately its destruction - this in contrary to the IAEI
experiences and discussion paper on MOVs at
http://www.iaei.org/subscriber/magazine/04_b/04_b_brown.htm
But this is inconvenient data so w_tom just avoids it or misquotes it.

Finally w_tom claims that I think plug in Power protectors are effective -
This is just an insult and a Blatent lie on w_toms part

Next there are some questions regarding statements that w_tom has told in
the past that he has still not answered :

Tell me again tom what a Thermal Fuse is.

Tell me the fairy tale again about how Lightning is a 'Low energy event'

Identify the 'direct connection between AC mains and the Integrated circuits
in a modern modem' for me.

explain how 0.6mm diameter single strand copper wire has a lower impedance
than 2.5mm square multistrand copper wire and therefore provides a better
earth.

Tell me again how Telco gear and TV/Radio Transmitters never ever suffer
Lightning damage.

Tell me how long your 1KJ mov lasts in a Direct Lightning strike ?

how long does a surge last ? - what is the definition of a surge ?

Remind me again when the MOV was developed ? - I  thought w_tom had finally
caught on to this one and I could leave it out but the latest posting
indicates otherwise

But then again I am probably assuming w_tom understands enough basic physics
to answer these questions.....

************************************************************

Now on with the rest of the show in which w_tom spins some more
misinformation -


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w_tom is so stupid he quoted what I said directly - that MODERN Call centers
are fed by Fibre optic cable then he questions if call centers in the 1930's
used fibre optics?
- well I dont know about other folk but I hardly consider 1930's Technology
to be Modern. w_tom's Diatribe is chock full of such Lies and Misquotes that
you cannot really believe a word that he writes.

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Ah just when I thought that w_tom had learnt when MOVs were invented he
regresses.

- As per usual w_tom misquotes and Lies in order to win points he so
desperately needs - a Clue here 'w' you are about 20 Years too early if you
are trying to use this to demonstrate how good MOVs are.

If you are trying to illustrate how important Earthing is well then again
you are trying to squirm in another direction - I have already pointed out
how important Earthing is that was never in dispute except in your mind.

What is in dispute is:
Your belief in the 100% effectiveness of MOVs for Lightning protection
Your belief that the lack of damage to Telephone exchanges proves that MOVs
are 100% effective (especially when Exchanges do not even typically use
MOVs).
Your assumption that an Earthing system adequate to to absorb a Single
Lightning strike without a signifcant EPR is not only feasible for the
average home owner but inexpensive.


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and Again w_tom shows that he knows nothing about Telecommunications and has
never worked in the Industry (or has he changed his tune slightly)
Lightning damage to Telephone exchanges does happen (Note I am not saying it
is common merely that it does happen) - despite the best Earthing and
Protection available In contradiction to w_toms continued and erroneous
claims of 100% effective protection.

Next w_tom assumes that this is big News- on the contrary it is so common
(Note that it is rare for a complete exchange Failure but individual Line
cards etc being damaged by Lightning is not an uncommon event following a
Thunderstorm) that equipment gets damaged in some way by Lightning that it
hardly rates a mention in the news and sparing for this is allowed for by
most sane Network engineers (Yes I do maintain a Stock of spares
specifically for Lightning damage for the ADSL Network I run - a clue to the
Aussies this network is currently about the third largest ADSL Network in
Australia).

Lightning damage is basically a calculated risk where you do all you can to
avoid it BUT it still happens from time to time as contrary to w_toms Lies
there is no 100% effective Lightning protection available and it is the cost
of doing business like all other failures in the Telco game (Back-hoe fade
etc ).

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Must have been a damn thin issue of the Bell system Technical Journal In
October 1960!

Because we go from Volume 39 Issue 5 In September of 1960 which has the
contributer acknowledgements starting page 1379 to the Next article
("Signalling Systems for the control of Telephone switching") in Volume 39
Issue 6 starting page 1381 on November 1960.

It looks suspiciously like they did not publish a Bell System Technical
guide in October 1960!

Ooops have I just caught w_tom out in yet another lie ....

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Remind me again what Technology the Exchanges used in the 1960's ?
w_tom extraoplates that Because Strowger gear was less susceptible to Surges
and Lightning damage therefore modern computerised exchanges are also.

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Hang on Computer based exchanges in 1960 ??? - there may have been one or
two but they were hardly common then.

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well actually w_tom is incorrect again. MOVs may have been used in the
1960's for Strowger exchanges but the Carbon block arrestor that he claims
in an earlier post was a MOV is actually a spark gap and this type of
arrestor also often included fuses or 'Heat coils'.

- once again because w_tom knows nothing about Telecommuncations he just
invented a few more facts to suit himself....

Gas discharge Tubes are generally used nowadays in Telephone exchanges
if/when surge supression is installed at the MDF (actually common in small
country exchanges) with semiconductor diodes (aka Transils, Transzorbs) used
on the Line cards themselves - Note Gas discharge tubes are unsuitable for
use on AC Mains which is why w_tom cannot rave on about them (just watch -
w_tom will devote the next post to why Gas discharge tubes are unsuitable
for Mains use and then pretend I said they were).

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He gets sooooo close and then misses the point entirely - geez if he had a
brain he would have worked it all out long ago. This is mainly due to the
way an Exchange is set up but effectively presents some Series impedance -
which was a point I raised.

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Well of course when w_tom says enough crap he has toget something right
eventually - Note though that he carefully avoids my statement that Earthing
was critical and where I pointed out that a Single Earth stake was woefully
inadequate to handle a lightning strike.

- but w_tom has been unable to answer any of the points I raised last post
so instead he makes up points he can answer

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w_tom is is not a real name and is therefore an annonymous poster who goes
to great effort to hide who he is whereas I am a real person and use my real
name.
This is because at the end of the day w_tom is not prepared to stand behind
his advice.

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Well w_tom does not quote facts, Numbers or even genuine articles as he
knows that they can all be shot down in flames So lets try a few of our own:

a Good ground resistance for a single earth stake is considered to be 5-10
Ohms
the current in a typical Lightning strike is 30,000 to over 200,000 Amps
Lets take the lowest Figures of 5 Ohms at 30,000 Amps

5*30,000 gives us an EPR of 150,000 Volts

what this means is that in the event of Lightning being shunted to the Earth
stake then the Earth stake will rise to 150,000 Volts above ground (at best!
at worst try about 2,000,000 Volts).
Of course w_tom will claim that Lightning is mysteriously different and does
not follow Ohms law but he will be as usual unable to explain why or prove
this.

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And as illustrated above single Earth stakes are inadequate (which is why
exchanges use multiple stakes) and multiple earth stake earthing systems are
not practical in most domestic situations so even if MOVs were 100%
failproof (they are not) you still would not be able to claim (as w_tom
does) that they offer 100% effective protection .......



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