Telescope Reviews: Surge protection for observatory

Unfortunately, when one knows only from observation, then junk science results. First, all incoming phone lines have a superior surge protector installed free by the telco. A 'whole house' protector located where their wires meet yours. A protector that has existed generations before the PC ever existed. A protector that every electrically knowledgeable tech would know of. Unfortunately, too many only know from what they see. Observation alone results in junk science conclusions. To have a fact, one must also learn the fundamentals.

Yes, many have seen a damaged modem. A surge ignore the telco 'provided for free' protector to destroy the modem - then stop? Of course not. Electricity does not work that way. First electricity (current) is simultaneously everywhere on a path from cloud to ground. That means a surge incoming on the modem is simultaneously outgoing on the modem. Where did that surge continue out of the modem? The modem did not stop a surge – contrary to popular belief.

How a modem is typically damaged: Lightning strikes AC electric wire down the street - highest wires on the pole. Does not strike lower phone wires. Incoming on AC electric. Through fuse box, into computer via AC mains, out via the modem, and to earth via phone lines. Since all phone lines have a 'whole house' protector, lightning found earth ground destructively via the modem. The typical failed part in that path is a PNP transistor that drives the off-hook relay.

What makes a surge easier to find earth via the modem? A plug-in protector. A protector too close to the computer AND without that always required 'less than 10 foot' connection to earth. That protector can even contribute to modem damage.

Once permitted inside the building, a surge will find earth destructively via electronics. Most modems are damaged due to surges entering on a utility wire without protection – AC electric.

Why do so many not learn this? The more informed literally repaired modems by identifying and replacing damaged semiconductors. And needed more than observation to know anything, Damaged modems typically have a failed PNP transistor that drives an off hook relay. That transistor is a path from cloud to earth. Either the transistor fails shorted (modem causes the line react to a phone off hook for too long), or transistor fails open (modem cannot connect to phone line). Either way, typical error message is "No Dialtone Detected". Many modems damaged by direct lightning strikes and repaired by me are still functioning today because we required more than just observation. Either the surge is earthed before entering the building OR surge damage due to human failure is expected. That comes from knowledge well proven even 100 years ago.

All phone line have a 'whole house' protector installed for free by the telco. Often located in an NID box. But a protector that will only be as effective as the earth ground provided by the home owner.

A protector is only as effective as its earth ground - which is why direct lightning strikes to the CO (about 100 per thunderstorm) never learn the entire town without phone service. Each line of defense is only defined by the earth ground – not by any protector. How good is each protection layer? How good is that layer’s earth ground. Plug-in protectors have no earth ground – therefore do not even claim protection in numeric specs. Each protection layer is only as good as and defined by its single point ground.