Coax power surge protector

[Mr__Bill]

I bought it for the new TV. Specifically because it had protection on the antenna coax, and it was inexpensive. But, when in line with the TV it filters out or does not let through about half of the stations. When I check it with a meter I see that there is no connection between the center contact of the two F connector connections. The shield has continuity but not the signal. Now I know it's not a lightning arrester but was hoping that what got past the arrester at the base of the antenna would be stopped by this.

My question is, should the signal contacts not be connected? I have no other coax surge protectors to test. This thing is made by Monster, is that the problem?

Bill
on the left coast

[LCHIEN]

it may be AC-coupled on the coax meaning it lets RF through but not DC. In which case your ohmeter won't measure it since it measures DC ohms and not high frequency impedance. OTOH I've seen some baluns and filters made in the far east that were so badly assembled they might not have been connected which would explain your signal loss. I would say if you don't get half the signals take it back and get another. Not much use if it doesn't pass all the TV RF signals.

[Cochese]

I did some research before buying my UPS on the wisdom of trying to power protect the coax. Like all things on the internet there was confusion and claims made to both protect and leave the coax unprotected. Most of what I saw and trusted said that there wasn't much benefit to protecting the coax as long as your house had a good ground. That any coax shield wouldn't be strong enough to do anything if you got a hit anyway. That the shield would do as you've noticed, just filter out content and provide questionable insurance.

I'm not an EE so I don't know how accurate those claims are. But it sounded reasonable enough to me that I went without.

[westom]

I'm not an EE so I don't know how accurate those claims are. But it sounded reasonable enough to me that I went without.

I am an EE and did this stuff for decades. An adjacent protector is ineffective for a long list of reason. Starts with no specification numbers.

A connection between shield and center conductor may exist. And no multimeter will detect it. A significant RF short is indicated by loss of channels and signal degradation. Degradation that occurs when using cheaper components designed only for lower frequencies.

Cable companies are blunt about this. They recommend no protector. Since best protection must be where a cable enters the building.

Best protection is a wire, as short as possible, from cable to single point earth ground. Not any ground. And definitely not safety ground in a wall receptacle. Single point earth ground. All four words have engineering significance.

How do centimeter parts inside that Monster stop what three miles of sky could not? That should have been glaringly obvious. But then one word on that protector screams scam. Monster has a long history of identifying illusions. Then selling equivalent products for even higher prices. Monster sold speaker wire labeled with amp and speaker ends. Reverse that wire and many said they could even hear subverted sound. Monster sold seven dollar speaker wire for $70 because so many want to be deceived. Where are spec numbers for a Monster product that claims to do the protection? Good luck. Marketing that works on people who prefer to stay naive. Who never demand numbers. And who know something is better only because it is more expensive.

Critical to protecting the TV starts by inspecting what does protection. Single point earth ground and how each incoming wire connects to it.

[Cochese]

I am an EE and did this stuff for decades. An adjacent protector is ineffective for a long list of reason. Starts with no specification numbers.

A connection between shield and center conductor may exist. And no multimeter will detect it. A significant RF short is indicated by loss of channels and signal degradation. Degradation that occurs when using cheaper components designed only for lower frequencies.

Cable companies are blunt about this. They recommend no protector. Since best protection must be where a cable enters the building.

Best protection is a wire, as short as possible, from cable to single point earth ground. Not any ground. And definitely not safety ground in a wall receptacle. Single point earth ground. All four words have engineering significance.

How do centimeter parts inside that Monster stop what three miles of sky could not? That should have been glaringly obvious. But then one word on that protector screams scam. Monster has a long history of identifying illusions. Then selling equivalent products for even higher prices. Monster sold speaker wire labeled with amp and speaker ends. Reverse that wire and many said they could even hear subverted sound. Monster sold seven dollar speaker wire for $70 because so many want to be deceived. Where are spec numbers for a Monster product that claims to do the protection? Good luck. Marketing that works on people who prefer to stay naive. Who never demand numbers. And who know something is better only because it is more expensive.

Critical to protecting the TV starts by inspecting what does protection. Single point earth ground and how each incoming wire connects to it.

That's exactly what I read, but couldn't remember the term.

I also really don't like Monster, but didn't want to mention it.

[phrog]

That's exactly what I read, but couldn't remember the term.

I also really don't like Monster, but didn't want to mention it.

You can be dubious about a company named "Monster?"

[chopnhack]

What is that plastic standoff on the plug side? Don't know if its the photo, but it looks like it would prevent you from completely inserting into the recept.

[LCHIEN]

What is that plastic standoff on the plug side? Don't know if its the photo, but it looks like it would prevent you from completely inserting into the recept.

goes into the 2nd socket ground socket hole to stabilize the connector. Supposed to cover up both pairs of a duplex outlet.

[Mr__Bill]

Thanks to all who responded. The Monster has been returned and I'll buy an APC surge arrester when next I see one for sale, they have a few direct plug units. I expect that if it had been more expensive I would have researched it and not have been bamboozled by Monster.

There is a lightning thing installed by Direct TV that is inline with the antenna lead, I'll rely on it and as I have done in the past when a lightning storm is headed my way I'll disconnect the TV from the wall, power and antenna.

I have never been a fan of Monster's Marketing. It's interesting how many sales people insist that you get better digital signals with gold plated connectors and that really loud base requires really big speaker wire. I had assumed that at least the quality was there along with the hype, in this case I had assumed wrong.

Now if I can just work out the WiFi issues I have with the TV..... but then if there was nothing to fix life would get boring.

Bill
on the left coast

[Slik Geek]

I'm a EE who has designed lightning surge protectors and tested them (with simulated lightning energy). I thought that a few clarifications might be warranted.

As westom noted, how can small parts do what three miles of sky cannot? A direct, "hot" lightning strike has so much energy that it would take significantly more protection than is practical (or perhaps even achievable) to even hope to have your equipment survive the strike.

But in reality, the odds are greater that a nearby strike will couple enough energy into your coax to still do damage. This higher likelihood event is where a surge suppressor can help.

An "adjacent" surge protector, if properly designed, can actually be very effective. The common industry strategy is to have three levels of protection: primary, secondary, tertiary.

The primary protector would likely be installed at the entry point to the building, where a large suppressor is placed and a very robust ground connection is available. This device will shunt the bulk of the energy to earth, but lets through enough of the surge that it can still cause damage to your device. This device clamps the energy to roughly 1,000 or 2,000 V.

A secondary protector reduces the energy and voltage further, to a couple hundred volts, and then a final protection device clamps the pulse to maybe 10 V, depending upon the application. The secondary protector is usually what the consumer installs when they add a surge protector. The final, tertiary protector is best done by the product designer on the circuit board. Alas, that involves a costly component which retail electronics developers like to avoid.

The major challenge is to sufficiently suppress the energy without suppressing the desired signal. This can be very difficult (and costly) with very high frequency signals, like RF on television coax. The addition of components that shunt energy to ground will also shunt some of the desired signal to ground. If enough energy from the signal is diverted, you get a degraded signal as the original post noted.

[Cochese]

Wish I had something tonight. Lightning hit pole across the street, fried the modem and I believe the motherboard of my main computer. Drives checked out fine, hopefully the processor and memory are okay.

Makes me rethink hooking it back up.

Sent from my HTC One using Tapatalk 4

[westom]

This discussion from an AT&T forum entitled "How can I protect my DSL/dialup equipment from surges?" describes how protection even from direct lightning strikes is implemented. These principles must be on each wire of every incoming utility cable. Otherwise lightning will go hunting for earth destructively via appliances:

Surge protection for DSL and dialup service.
Surge protection takes on many forms, but always involves the following components: Grounding bonding and surge protectors. ...

Grounding is required to provide the surge protector with a path to dump the excess energy to earth. A proper ground system is a mandatory requirement of surge protection. Without a proper ground, a surge protector has no way to disburse the excess energy and will fail to protect downstream equipment.

Bonding is required to electrically connect together the various grounds of the services entering the premises. Without bonding, a surge may still enter a premise after firing over a surge protector, which will attempt to pass the excess energy to its ground with any additional energy that the services surge protector ground cannot instantly handle, traveling into and through protected equipment, damaging that equipment in the process. ...

Now, if all the various service entrance grounds are bonded together there are no additional paths to ground through the premise. Even if all of the grounds cannot instantly absorb the energy, the lack of additional paths to ground through the premise prevents the excess energy from seeking out any additional grounds through that premise and the electronic equipment within. As such, the excess energy remains in the ground system until dissipated, sparing the protected equipment from damage. ...

By far, the whole house hardwired surge protectors provide the best protection. When a whole house primary surge protector is installed at the service entrance, it will provide a solid first line of defense against surges which enter from the power company's service entrance feed. These types of protectors can absorb/pass considerably more energy than any other type of protector, and if one does catastrophically fail, it will not typically be in a living space. ...

Plug in strip protectors are, at best, a compromise. At worst, they may cause more damage than they prevent. While they may do an acceptable job of handling hot to neutral surges, they do a poor job of handling any surge that must be passed to ground. ...

Then, to add insult to injury, some strip protectors add Telco and/or LAN surge protection within the same device, trying to be an all-in-one sale. Remember bonding? When Telco or LAN protection is added to a strip protector, if the premise ground, which is not designed to handle surges, cannot handle all of the energy, guess where that excess energy seeks out the additional grounds? You got it! The Telco and LAN connections now becomes the path, with disastrous results to those devices. ...

Source: http://www.dslreports.com/faq/10431