[SixClub] Recommended Coax?

[Roger (K8RI)]

On 6/16/2010 4:24 PM, KB0NLY wrote:
> If you had water running out of the rig then obviously you forgot the rule
> of using a drip loop in your feedlines as well...
>
> If lightning hit the tower and blew off the waterproofing you must not have
> used the right products... I have seen antennas melted and blown apart and
> the waterproofing on the coax connector is still fine.
>    
Lightning is unpredictable.  I used the same method back then as every 
one else with coax seal and tape over that. It split the coax seal 
lengthwise and then left it looking like a piece of expanded metal.  I 
never did find any of the tape.

Every coax connector "up there" even had the silver plating removed and 
was left looking like freshly sandblasted brass.

73

Roger (K8RI)
> 73,
>
> Scott
>
>
>
> --------------------------------------------------
> From: "Roger (K8RI)"<50MHz at rogerhalstead.com>
> Sent: Wednesday, June 16, 2010 1:45 PM
> To:<sixclub at mailman.qth.net>
> Subject: Re: [SixClub] Recommended Coax?
>
>    
>> When it  comes to 9913, (the quasi air core type) I threw out and gave
>> away over 1500 feet of the stuff and wouldn't use it for a door stop.
>> The foam filled is fine.  I used to belong to the group that said if you
>> seal and water proof the connections it'll be fine. Then lightning hit
>> the tower.  It removed every bit of water proofing up there.  In less
>> than 15 minutes I had water running out of the 2-meter rig. The rig
>> survived, the desk top did not.
>>
>> On 6/16/2010 2:42 PM, kd4e wrote:
>>      
>>> Based on this site:
>>> http://www.ocarc.ca/coax.htm
>>>
>>>
>>>        
>> I can only get part of that page to work and 9913 is not among the
>> choices for the calculator.
>> Typically the loss between 9913 and LMR-400 is negligible with LMR-400
>> costing less.
>>      
>>> Belden 9913 is a better brice-performance choice
>>> than most,
>>>        
>> The prices must have changed as when I put in the LMR-400 it was head
>> and shoulders above 9913 with about the same loss and much less expensive.
>>      
>>> except for Andrews Heliax, based on
>>> loss at 100' but at 150' it changes a little.
>>>
>>>
>>>        
>> Of the small cables the 1/2" Heliax has by far the least loss, but it's
>> not tolerant of tight turns.  LMR-400 can make a 1.5" radius (Non
>> repeatable) bend without the center connector migrating. It's also more
>> rugged when it comes to getting stepped on, or run over. It's also
>> easier to install on the inside of the tower without worry of kinking.
>> But other than that it's the best performer of the bunch. However don't
>> forget the cost of connectors. A pair of them for 1/2" Heliax will buy a
>> 100' of LMR-400 plus connectors. OTOH those connectors and the cable can
>> often be found as surplus or pull outs...unless I'm looking for some.
>>      
>>> Variables:
>>>
>>> 50MHz
>>> 100'
>>> SWR 1:1
>>>
>>> ........................Loss100'..Loss150'
>>> ---------------------------------------------
>>> Belden 9913..............0.885....1.328
>>> Davis RF Bury-Flex.......1.009....1.513
>>> LMR 400..................0.865....1.297
>>> Andrews LDF4-50A.........0.464....0.696
>>>
>>> What am I missing, please?
>>>
>>>
>>>        
>> 9913 and LMR-400 are nearly identical in loss with only 0.02 db
>> difference with LMR being the better.  LMR-400 is usually cheaper than
>> 9913 and far more rugged and will make tighter turns without the center
>> conductor migrating.
>> As I said, I'd not use the regular, quasi air core 9913 for a door
>> stop.  It makes a good water pipe.
>> The foam filled 9913 is a good coax, but more expensive the last time I
>> priced them.
>>
>> 73
>>
>> Roger (K8RI)
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>>      
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