Re: EOL's

["Nick Markowitz" <nick-markowitz@xxxxxxxxxxx>]

Looks like Robert is up to his old stunts again so here is my 2 cents worth
with 25+ years of residential and commercail  low voltage alarm and high
voltage 120 to 480 volts 3 phase work with resistors.Plus working as a
broadcast engineer at a 5000watt AM station.

I have seen the 2.2 k resistors on FBII equiptment go low
around 1500 ohms on 12 different  ocasions due to power surges and
enviromental conditions  and I have seen circuits with end line resistors
get tricked in metal buildings when the positive makes ground even with the
resistor in proper place the door was able to be opened and no reaction from
the panel.  Saw this happen with the old class A type loops with Holmes
Direct Wire equiptment which is why we never put the switches in the
posistive loop and in the olden days we ran the ground side of the alarm
circuit loop thru a copper water pipe in a building  to detect  circuit
tampering. or accidental circuit grounds.which was a requirement for UL burg
systems back then.
As far as resistors going high have only seen this 3 times and again
enviromental problems caused it when the resistors material deteriorated.
All electronic components eventually dry up and go bad thats why they say 10
years on most items made these days.Yes I have a 45 + year old radios down
stairs which still fire on but they are the exception not the rule.
The resistors made today are much higher quality than old days but they can
and do drift under the right conditions.
even the 5% tollarance ones.