DC Breakdown Voltage

[JMM-BDA]

I'm in the market for some more lightning surge supressors. The website I order a lot of my items from lists models that are basically the same, except those products vary by something called DC Breakdown Voltages.

I've managed to find some good posts & tutorials on here and the Internet about lightning protection, but nothing (so far) about what DC Breakdown Voltages means.

Is anyone able to explain what that means, or point me somewhere where I can read up on that term?

For example, they have:

0-3 GHz 90V Lightning Protector
0-3 GHz 230V Lightning Protector
0-3 GHz 350V Lightning Protector
0-3 GHz 600V Lightning Protector

The only difference listed is the Standard Gas Tube Element DC Breakdown Voltage. As lightning is a lot higher than those voltages listed, I was thinking that perhaps those voltages listed indicates at what voltage the lighning protectors starts to act to protect the equipment. Am I close to being correct? Or am I not even close? ;-)

Thanks in advance.

 

[smason]

The only difference listed is the Standard Gas Tube Element DC Breakdown Voltage. As lightning is a lot higher than those voltages listed, I was thinking that perhaps those voltages listed indicates at what voltage the lighning protectors starts to act to protect the equipment. Am I close to being correct? Or am I not even close? ;-)

Thanks in advance.

I believe you are correct. I think at the rated breakdown voltage the gas conducts, and shunts the current to ground. I could be wrong though....

 

[prcguy]

Are you sure the models you are looking at have a gas tube? Some models have a simple pointy spike inside and the gap between the spike and the center conductor determines the breakdown voltage. The breakdown voltage can also relate to the maximum RF power used in the system. A lighting supressor for a receive only system can have a very low breakdown voltage and kick in earlier than one designed to handle 2kw of RF. I think Polyphaser is probably the best of the affordable lightning protectors and many are available cheap on Ebay.
prcguy

I'm in the market for some more lightning surge supressors. The website I order a lot of my items from lists models that are basically the same, except those products vary by something called DC Breakdown Voltages.

I've managed to find some good posts & tutorials on here and the Internet about lightning protection, but nothing (so far) about what DC Breakdown Voltages means.

Is anyone able to explain what that means, or point me somewhere where I can read up on that term?

For example, they have:

0-3 GHz 90V Lightning Protector
0-3 GHz 230V Lightning Protector
0-3 GHz 350V Lightning Protector
0-3 GHz 600V Lightning Protector

The only difference listed is the Standard Gas Tube Element DC Breakdown Voltage. As lightning is a lot higher than those voltages listed, I was thinking that perhaps those voltages listed indicates at what voltage the lighning protectors starts to act to protect the equipment. Am I close to being correct? Or am I not even close? ;-)

Thanks in advance.

 

[JMM-BDA]

Thanks PRCGUY.

Sorry, I should've mentioned that I'll be using them for receive-only. And yes, they're gas discharge tube suppressors.

Here is the link to them.

The first 4 items are basically the same except for the voltages, so I have no idea the advantages & disadvantages, for example, of the 90-V versus the 600-V (which I assume there are, otherwise I can't imagine why they'd have a range of them).

So it would seem that for receive-only, all I would need is the 90-V model. Great, thanks!!

It's going to be a wee-bit overkill for me ..... I already have one of these HyperLink arrestors up at the antenna, plus an ICE model. Now I'm going to get 3 more of these HyperLink critters, to install in my fiberglass enclosure which houses my filter & pre-amp - one on the input to the enclosure (from the antenna), one on the output of the enclosure (leading to the house), and one where the cable enters the house (I recall reading somewhere that there should be one where the cable enters the premisses). Each of them will, of course, incur a penalty in slight loss of signal, but they're replacing N-N adapters on the enclosure anyway, which themselves incur a loss. So my thinking is, why not at least have a (false?) sense of security (and yes, I do unplug the connections into the enclosure & premisses during lightning storms). Now, if I had a long feed from antenna to scanner, then maybe it's not too much over-kill ..... but it's only 25' .

Anyway, thanks again for your help (as always) - much appreciated.

 

[prcguy]

I would recommend you visit the Polyphaser site and read some of their technical notes, specifically the "ham radio station protection". You would usually place the lightning arrestors at ground level, close to a good ground system and bond the arrestors to the ground system using conductors with much less resistance and inductance than the coax leading to your equipment. Any additional ground rods would need to be bonded to the house electrical ground to meet NEC code.

Unlike most companies that make lightning arrestor products (that's all they make), Polyphaser has a lightning lab and designs and tests their products under realistic conditions.

Sometimes Ebay has buy it now prices of $10 or less on some Polyphaser arrestors like this 125-1000MHz version, see Ebay item #350098905139.
prcguy

Thanks PRCGUY.

Sorry, I should've mentioned that I'll be using them for receive-only. And yes, they're gas discharge tube suppressors.

Here is the link to them.

The first 4 items are basically the same except for the voltages, so I have no idea the advantages & disadvantages, for example, of the 90-V versus the 600-V (which I assume there are, otherwise I can't imagine why they'd have a range of them).

So it would seem that for receive-only, all I would need is the 90-V model. Great, thanks!!

It's going to be a wee-bit overkill for me ..... I already have one of these HyperLink arrestors up at the antenna, plus an ICE model. Now I'm going to get 3 more of these HyperLink critters, to install in my fiberglass enclosure which houses my filter & pre-amp - one on the input to the enclosure (from the antenna), one on the output of the enclosure (leading to the house), and one where the cable enters the house (I recall reading somewhere that there should be one where the cable enters the premisses). Each of them will, of course, incur a penalty in slight loss of signal, but they're replacing N-N adapters on the enclosure anyway, which themselves incur a loss. So my thinking is, why not at least have a (false?) sense of security (and yes, I do unplug the connections into the enclosure & premisses during lightning storms). Now, if I had a long feed from antenna to scanner, then maybe it's not too much over-kill ..... but it's only 25' .

Anyway, thanks again for your help (as always) - much appreciated.

 

[JMM-BDA]

Thanks for reminding me about where I had read some very educational notes in the past - couldn't remember where I had seen them.

As for the Polyphaser website itself, their products may be great, but IMHO their website is pretty pathetic when it comes to describing their products. I must've spent hours on there in the past, and again this evening, trying to determine the best lightning suppressor for my needs, but once again came away confused.

I must admit, though, that reading their TD1001: The best RF protector for applications not requiring dc on the coax, I was able to digest at least a little bit of useful information, in that I assume they were trying to say that DC-Blocked RF lightning protectors are better than gas tube protectors, the latter which I have now & up until now was about to purchase more of.

So I then perused their website looking at suppressors, and they say that Where the best protection is a must, use the IE (Isolated Equipment) ...... And so off I went to read up on their IS-IE50LN-C0, only to find that they mention almost nothing about it. Even a Google search on that part number revealed a total of only 6 hits, but only 2 related to any Polyphaser product. And that's supposed to be their line of suppressors that provides the best protection?

Sorry, I've gotten off-topic on this post. Thanks again for pointing me back to the website where I found some good informational reading, though - much appreciated.