[TowerTalk] Coax type selection

[Joe - WDØM]

Not much in the way of of lightning where I lived on the coast of 
Alaska.  However, here in southwest Colorado, we are among the highest 
strike areas in the state.  I just lost an HDTV, Bose stereo, computer, 
and the SteppIR controller when a bolt of lightning hit my tower.  
Everything else - all my ham gear - came through OK.  I've never had a 
problem with the LMR400 here in CO, nor the Belden 9913 in Alaska.  
Lightning is a great equalize and all bets are off.  However, I didn't 
have to do anything to the LMR400 post lightning strike.  You are 
correct about the gentle radius curves required for 9913 or you will 
face center conductor movement.

73,

Joe
WDØM

Roger (K8RI) wrote:
> Joe - WDØM wrote:
>   
>> Belden 9913 has had a history of water leaking into the interior through 
>> improperly installed connectors.  
>>     
> I used to say that, but then a lightning strike took off all the tape 
> and coax seal at the top of the tower.  15 minuets later I water running 
> out of the one rig and onto the desk top. Ruined the desk top. 
> Surprisingly the radio was OK.  Within the month I had removed all 9913 
> from service and was replacing it with LMR-400, which as since been 
> replaced with LMR-600
>   
>> I've never experienced that, even when 
>> I lived in Alaska and used 9913 for all my gear with temps running -40 F 
>> and 125 mph winds.  I now have LMR400, and I'm happy with it.  Either 
>> one works, as long as you take care when installing the connectors.
>>   
>>     
> Although doing the connectors properly is required, it's still not 
> enough if you live in lightning country.  My tower has now had 17 
> verified direct strikes and I've had to reseal the connectors on top 
> countless times.
>
> Another problem with 9913 is center conductor migration in bends 
> although for most instances this is not much of a problem.  However I've 
> heard reports of the center conductor moving in vertical runs causing 
> poor connections with N-connectors.
>
> I gave away about a 1000 feet of 9913 that was less than 5 years old, 
> and threw out about 230 feet.
>
> My one antenna suddenly started showing an intermittent high SWR as if 
> there were an arc some where.  I was able to pull enough of the cable 
> out of the conduit to get at a splice. When I took the splice apart, 
> water ran out. The wind had blown the cable against the edge of the roof 
> where the shingles abraded the jacket letting in water.
> That was the only piece of 9913 I had left installed. I though I had 
> gotten rid of all of it.
>
> 73
>
> Roger
>   
>> 73
>>
>> Joe
>> WDØM (ex-WL7M)
>>
>> Tommy wrote:
>>   
>>     
>>> Could someone please explain to me why LMR-400 seems to be preferred over
>>> Belden 9913 for coax feed line? They have about the same attenuation/100' at
>>> 28 MHz, 9913 has a non-contaminating jacket and 9913 cost a little less than
>>> LMR-400.
>>>
>>>  
>>>
>>> Comparing the specs of both, leads one to believe they are just about
>>> equivalent, however, I must be missing something?
>>>
>>>  
>>>
>>> Thanks.
>>>
>>>  
>>>
>>> Tom - W4BQF
>>>
>>>  
>>>   
>>>
>>>     
>>>       
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>>   
>>     
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