[TowerTalk] Feedline Coil or Loop??

[Roger (K8RI)]

You said Steve, but responeded to my post so I'll answer. <:-))


> Steve,
>
> I have a couple of questions about the coil feed-line you are using.
> 1.  What is the diameter of the coil around the mast?

About 18" (2 turns)

> 2.  What is the size of the tower top plate?

ROHN 45G (about 18")

> 3.  Over the years, does the constant (or should I say frequent) moving of 
> the antenna direction cause wear on the bottom of the coax outer jacket 
> where it rubs against the tower top plate?

It hasn't so far and that top plate is the typical galvanizing meaning it's 
fairly rough.
There is very little movement of the coax even running contest type of 
operation.

> 4. Do you have any sort of smooth slippery material on the top plate of 
> your tower (such as teflon or a plastic cutting board material, or is it 
> just the galvanized metal?

Just plain old galvanizing.

In http://www.rogerhalstead.com/ham_files/Tower29.htm the cables have not 
been positioned yet and you can see a big loop sticking up to my left. That 
loop contains a run to each system.  440, 144, 50, and the tribander. Hmmmm 
I mis spoke earlier, there are only 4 runs in the bundle. The 5th goes to 
the remote switch (not visible) just below my feet. The TV antennas were not 
yet in place when this shot was taken.

73

Roger (K8RI)

>
> Thanks for your help.
>
> 73,
> Jeff, K3DUA
>
>
>
>
> On Jul 23, 2007, at 4:36 PM, Roger (K8RI) wrote:
>
>> As far back as I can remember (IIRC) I've used this two turn coil laying 
>> on
>> top of the tower.
>>>
>>>    I've used it many times. It's easier with one or  two cables - more
>>> starts to cause coiling/uncoiling problems.
>>>
>> I'm doing it with 5 runs of LMR 400 Ultraflex, (soon to be LMR 600 flex) 
>> and
>> no problems in over 5 years
>>
>> Roger (K8RI)
>>
>>
>>> Cheers,
>>> Steve     K7LXC
>>> TOWER TECH
>>
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