[TowerTalk] Coax Grounding on a tower.

[K8RI on Tower talk]

> Did you consider the Polyphaser grounding kits? AFAICS from the
> literature, you strip off the outer jacket, clamp one end of the copper

I'd never heard of them. I'll have to look into them if I can find the 
information.  I've been reluctant to cut the jacket any place to make up 
something like this, but the Polyphaser might be just what I'm looking for.

Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
www.rogerhalstead.com


> strip around the exposed braid, then seal the whole thing up and connect
> the other end to the tower. This would eliminate the additional
> connectors with their possible impedance bumps.
>
> There are several versions of the kit. AFAICS (again -- I've not used
> their kits), the copper strip is plated with some suitable metal so as
> not to result in corrosion of the metal to which it is connected at each
> end -- copper, galvanized, tinned, etc.
>
> Has anybody used these? How successfully?
>
> 73
>
> Alan NV8A
>
>
> On 06/26/06 10:02 pm K8RI on Tower talk wrote:
>
>> Due to basement work I've had to pull all the cables out of the conduit.
>> Man, but I was sore the other day and was wondering whey until I realized
>> I'd pulled between 1300 and 1500 feet of cable out of conduit the 
>> previous
>> evening.
>>
>> This has put me off-the-air with the main station which is probably why
>> 6-meters has been open the last couple of weeks.
>>
>> As this is turning into a rotator repair (It's hanging up again and the
>> thrust bearings are free), antenna repair, antenna removal, replace the 
>> pig
>> tails, and reroute the coax project I've decided that as long as the coax
>> has to go through connectors at the end of the pigtails at the top of the
>> tower I'm going to mount an aluminum angle across the face of the tower 
>> with
>> 3" UHF feed throughs.  Each of the current 4 pig-tails will fasten to a 
>> feed
>> through which will ground the brade to the tower at the top. The cables 
>> then
>> run down the inside of the NE tower leg where they are joined by two more 
>> to
>> the base and loop up into the junction box where they enter the 3" 
>> conduit
>> to the house.  The cables will be jointed by at least one or two more 
>> part
>> way down the tower, but there may be two less from the top.  The easiest 
>> is
>> to just say the number may vary.
>>
>> My thoughts are to either use another set of bulk head connectors on
>> Aluminum angle bracketed to the tower as at the top, or to clamp those
>> brackets to the leg of the tower using a hose clamp and spacers so the
>> center part of the feed through will be grounded to the tower leg.
>>
>> This will add one more set of connectors to the cables but from 
>> experience
>> and information gleaned from TT I'd say the insertion loss of the one 
>> extra
>> connector is going to be almost non existent. In addition the cables will 
>> be
>> grounded to the tower where they are leaving the tower.
>>
>> The new junction box at the house entrance will be putting the shield
>> grounds and the Polyphasors (sp?) right outside  the house at the point 
>> of
>> entry where they are currently just inside the house.  I think this will 
>> be
>> an bit of an added safety feature.
>>
>> One leg of the tower ground system will be entering the Hoffman box 
>> beside
>> the conduit, grounding the back plate inside and then continuing into the
>> house with the other cables. This #2 runs directly through to the house
>> ground for the electrical service as it's the only way I can get it 
>> there.
>> I'd have to tear up a rather expensive garage apron to get there outside 
>> and
>> that would make the grounds different length.
>>
>> This is going to get rid of the conduit coming through the basement wall.
>> It'll come in through the end plate of the floor joists and there will be 
>> no
>> cables showing below the basement ceiling.  At least that is the plan.
>>
>> Remember it's normal for this installation to take at least three 
>> lightning
>> hits a year and I think it's already had it three (or more) just in the 
>> last
>> storm.
>>
>> Any socially acceptable suggestions?
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