Types of Polyphaser Lightning Arresters

[productionguy85]

I have seen on the Polyphaser website that they have Bias-T, DC Block and DC Pass, lightning arresters. Wondering what the difference is between the 3 types and which one is better (and worse). I have specifically seen on a military tower a model that is in the DC Pass category, so I am leaning towards that, but would like to know the real difference.

Thanks

 

[Thunderknight]

Bias-t: inserts DC in the coax for an amp
DC pass: allows DC on the coax to pass through the arrester.
DC block: DC on the coax stops at the arrester.

 

[productionguy85]

Bias-t: inserts DC in the coax for an amp
DC pass: allows DC on the coax to pass through the arrester.
DC block: DC on the coax stops at the arrester.

Sorry I didn't clarify, I know what DC Pass and Block "means". I should have reworded the question better. What exactly is the Direct Current that is it blocking (or passing), the power to a Tower Top Amp? or something else?

 

[mmckenna]

Yes. I've got some DC pass units in use for tower top amps and GPS antennas that require a +5vdc.

 

[prcguy]

The original Polyphaser arrestors were DC block, which helped simplify the design and later they came out with DC pass which has more parts to contend with.
prcguy

 

[productionguy85]

Thanks everybody, now how about the gas filled models? Are they better for lightning protection? What is the best type to get/ use?

 

[jim202]

Thanks everybody, now how about the gas filled models? Are they better for lightning protection? What is the best type to get/ use?

Maybe you should try reading the information that is on the web site from the company that your asking about. Any answer you get here is subjective. It is based on what that individual thinks and may not be the best answer based on the true facts of the product in question your asking about.

There are many of us with lots of years of field practice under our belts that have learned the good and bad the hard way. Not everyone that comes to us, takes those many years from the college of "HARD KNOCKS" and believes the advice that is given.

 

[productionguy85]

Maybe you should try reading the information that is on the web site from the company that your asking about. Any answer you get here is subjective. It is based on what that individual thinks and may not be the best answer based on the true facts of the product in question your asking about.

There are many of us with lots of years of field practice under our belts that have learned the good and bad the hard way. Not everyone that comes to us, takes those many years from the college of "HARD KNOCKS" and believes the advice that is given.

This all the explanation that is given for each section.... it does NOT explain, what the purpose of ie gas filled protectors are for. Which is why I am asking here, to learn about them and to be able to make an informed decision as to which protection device to purchase the first time... Isn't that one of the benefits/ purposes of these forums (to discuss products)?

..."lightning protection devices by PolyPhaser offer the industries best performance. Our patented designs are engineered for low voltage let through and superior RF performance."

 

[prcguy]

I'm a fan of Polyphaser and would suggest anyone wanting to learn about lightning protection to read this publication from Polyphaser: http://members.rennlist.org/warren/LightningProtectionAndGrounding.pdf
I hope there is no copyright infringement from whoever posted it on the Internet since it originally cost about $20.

Anyway, the gas filled protectors work by connecting a little capsule containing a gas across the center conductor and ground of the coax and the gas conducts at a certain predicted voltage. The voltage where the gas ionizes and shorts the center conductor to ground is based on how much RF power the lightning arrestor is rated for so it doesn't conduct during normal operation but it will conduct with higher voltages from a lightning strike. When the high voltage condition (strike) is done the gas tube usually returns to normal or it may be permanently shorted but most models allow you to easily replace the gas tube.

Polyphaser in general does not use gas tubes and one potential problem is the arrestor is at a remote location and the radios will not operate until someone fixes the blown gas cartridge. Most Polyphaser arrestors are designed to take multiple hits and not need replacement except in extreme cases.
prcguy

 

[productionguy85]

I'm a fan of Polyphaser and would suggest anyone wanting to learn about lightning protection to read this publication from Polyphaser: http://members.rennlist.org/warren/LightningProtectionAndGrounding.pdf
I hope there is no copyright infringement from whoever posted it on the Internet since it originally cost about $20.

Anyway, the gas filled protectors work by connecting a little capsule containing a gas across the center conductor and ground of the coax and the gas conducts at a certain predicted voltage. The voltage where the gas ionizes and shorts the center conductor to ground is based on how much RF power the lightning arrestor is rated for so it doesn't conduct during normal operation but it will conduct with higher voltages from a lightning strike. When the high voltage condition (strike) is done the gas tube usually returns to normal or it may be permanently shorted but most models allow you to easily replace the gas tube.

Polyphaser in general does not use gas tubes and one potential problem is the arrestor is at a remote location and the radios will not operate until someone fixes the blown gas cartridge. Most Polyphaser arrestors are designed to take multiple hits and not need replacement except in extreme cases.
prcguy

Thanks for the info and the link to that publication. I am just glancing over it and have already found answers to my next questions. Thanks again prcguy