Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: Polyphaser location  (Read 1847 times)
WALTERB
Member

Posts: 528




Ignore
« on: July 03, 2013, 08:14:14 AM »

I would like to hear from those who have a common grounding system (house ground, shack, tower, all connected to common ground) and DO NOT disconnect the coax during thunderstorms.

What is the location of your polyphaser(s) (lightning arrestors).  The base of the tower, in the shack, etc.?

thanks in advance.
Logged
K1CJS
Member

Posts: 5871




Ignore
« Reply #1 on: July 03, 2013, 08:25:54 AM »

Directly outside the co-ax/cable entry point to the house--which is right below the shack.  The arrestor panel has the station ground from inside bonded to it, and the panel is bonded to a ground rod right below it.  A number 2 cable (which I had from another job and used) connects that ground rod to the house main ground rod which is about 25 feet away with two other ground rods and bonds spaced evenly along it.
« Last Edit: July 03, 2013, 08:28:24 AM by K1CJS » Logged
KE3WD
Member

Posts: 5694




Ignore
« Reply #2 on: July 03, 2013, 12:15:06 PM »

Polyphasor has instructions for installation, or at least they used to, good stuff, hope they still web publish it. 

I put them on their own Ground Panel, made of copper plate, just outside the penetration into the building. 

For single antenna installations, have ground mounted them right next to the antenna, say, a vertical, with a ground stake at the bottom and the polyphasor mounted in a box attached to the stake. 

73
Logged
WALTERB
Member

Posts: 528




Ignore
« Reply #3 on: July 03, 2013, 12:28:25 PM »

Polyphasor has instructions for installation, or at least they used to, good stuff, hope they still web publish it. 

I put them on their own Ground Panel, made of copper plate, just outside the penetration into the building. 

For single antenna installations, have ground mounted them right next to the antenna, say, a vertical, with a ground stake at the bottom and the polyphasor mounted in a box attached to the stake. 

73

thanks, I hunted for instructions, but couldn't find anything immediately, maybe I didn't look long enough.

thanks.
Logged
WALTERB
Member

Posts: 528




Ignore
« Reply #4 on: July 03, 2013, 12:36:49 PM »

I was told by multiple people that they should be placed at the base of the tower. However I have mine in the ham shack on a common / universal grounding bus that is grounded to the house ground, grounding bus outside the shack where the bulkhead / coax barrel connectors are.  

I'm reading Alpha-delta's  "WHERE TO LOCATE", and it says "As close to the equipment as practicable, which is what I have.  

http://www.alphadeltacom.com/pdf/TT3G50_instruction_sheets-6.pdf
« Last Edit: July 03, 2013, 12:42:00 PM by WALTERB » Logged
KE3WD
Member

Posts: 5694




Ignore
« Reply #5 on: July 03, 2013, 03:09:31 PM »

The large repeater system where I specified polyphasors, we did install them on the wall in the same room as the multiple repeaters, right behind the cabinets and cans.  On a grounded plate. 

http://gpvhf.homelinux.org/jpg/lighting.jpg


I think that good earth grounding of the polyphasors is the most important part. 

BTW -- they work.  Have proven that empirically, time and time again. 


73
Logged
WALTERB
Member

Posts: 528




Ignore
« Reply #6 on: July 05, 2013, 06:49:18 AM »

The large repeater system where I specified polyphasors, we did install them on the wall in the same room as the multiple repeaters, right behind the cabinets and cans.  On a grounded plate. 

http://gpvhf.homelinux.org/jpg/lighting.jpg


I think that good earth grounding of the polyphasors is the most important part. 

BTW -- they work.  Have proven that empirically, time and time again. 


73

thanks.
Logged
K3GM
Member

Posts: 1767




Ignore
« Reply #7 on: July 05, 2013, 10:33:12 AM »

I wanted to point out that the popular IS-B50HN-C1 model and the rest of that type of arrestors are not fully weatherproof.  It is highly advisable to  place them in an enclosure and out of direct exposure to rain and snow.
Logged
KZ1X
Member

Posts: 3227




Ignore
« Reply #8 on: July 06, 2013, 03:45:54 PM »

I have a 80' Phillystran guyed 55G tower with 16' of mast above it, lots of wires, coaxes, and the works.  I live in NC.
Lots of lightning.

I have *never* disconnected anything since the tower went up to full height around 1998.  My gear is always hooked up.
In all that time, I have had only two minor connector failures due to my own ineptitude, not due to lightning.

Why?

Because I correctly grounded the tower. 

I got lucky, because in my youth I worked for a firm that did AM broadcast station engineering work.  So, I learned not only what to do but how to do it, from some wizened old guys who sadly are now SK.

That was over 30 years ago that I had that job.  Time sure goes fast!

Yes, I did add suppressors, like several sets of Polyphasers as you are describing, but these are NOT the way to stop damage; they are an adjunct.  I have seen Polyphasers blown apart!  The ones I have are the original ones from when I installed them.

One thing I have noticed over the years are comments from visitors to my station who say things such as "gee that looks like overkill"  "you spent way more on that that I would" "why did you use such a heavy wire?" "you put in HOW many ground rods?" "I've never seen anyone else do that" and of course, I smile and acknowledge these in a friendly and discreet manner.  "Sure, you know, you're probably right, many people don't do all that." 

More than one of these guests are known to have sustained lightning damage.  I shake my head and am grateful nobody was hurt.

And then I come on line and read about all the lightning damage other people get, or that they run to unhook wires and throw the out the window every time it looks like rain, etc.. so, you're correct in being concerned.  It isn't impossible to stop the problem, the commercial guys do it all the time.  Look at any cell tower for example.  There are several guaranteed to be nearby.

So ... where does a ham go for information?

This web site is a good start 

http://www.w8ji.com/station_ground.htm

but I would argue that Tom went 'light' on things.

Here's a terrific article on the topic:

http://www.copper.org/applications/electrical/pq/casestudy/nebraska.html

Other good links:

members.rennlist.org/warren/ground.pdf
www.crawfordbroadcasting.com/Eng_Files/Lightning%20Protection.pdf‎

Logged
KE4JOY
Member

Posts: 1335




Ignore
« Reply #9 on: July 08, 2013, 04:48:48 PM »

Here's a terrific article on the topic:

http://www.copper.org/applications/electrical/pq/casestudy/nebraska.html

[/quote]

I would pay good money to see a 40'-0" ground rod driven...  Grin
Logged
K1CJS
Member

Posts: 5871




Ignore
« Reply #10 on: July 09, 2013, 05:00:31 AM »


I wouldn't pay to much mind to that article because of this one sentence:  
"FM antenna towers and the guy wires that support them are always grounded (unlike AM towers, which are insulated structures)."

Older style AM stations where the towers themselves were the antenna were insulated--but there are other AM stations where the tower structure IS grounded, with the radiator (antenna) insulated from the tower at a high level.  If the author got that one thing wrong, it stands to reason that there may be other things in the article that could be just as wrong.
« Last Edit: July 09, 2013, 05:03:09 AM by K1CJS » Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!