[AMPS] N Connectors

[measures]

>
>Does anyone know the RF voltage/current rating (at sea level) of a typical 
>type N connector. 
>I have heard various opinions on this connector ranging from "It should 
>never be used in high
>power applications at HF" to "You can 10KW thru them". Recently, I have 
>seen two
>catastrophic failures involving type N connectors at HF frequencies. In 
>both cases, the male
>center pin and the female socket were welded together and the connection 
>was filled with
>black carbon like deposits. In both cases, legal power was involved 
>(Ameritron AL-82 and
>Alpha 78). 

I have put 14kw pep (1200v-peak) through a N fitting at 7MHz.  .  
However, if a Type N center  pin looses spring tension there can be 
grief.  A better connector is the Type-C..  It's like a BNC for RG-213.  
A Type-C fitting has way more contact area than a Type-N.  
>
>With a 1:1 VSWR into 50 ohms, 1500 Watts corresponds to 5.5 amps rms and 
>270 volts rms 
>respectively. Given the airgap size in the series N connector, I would 
>expect the breakdown 
>voltage to much higher than this (one old Mil spec I found for a type N 
>adapter suggested 

I measured it at c. 4kV. 

>1500 volts rms). My gut feeling is that these failures are due either to 
>improper installation,
>or poor quality connectors (plastic dielectric vs teflon). Are there any 
>published specifications
>for the series N (UG-21) connector and the UHF connector (PL-259) that 
>compares there
>voltage and current handling capability in some meaningful way (I couldn't 
>find much on the 
>DSCC web site)? 
>
>One of the connectors that needs replacing is a 7/8" hardline to N 
>connector that is located 
>at the top of a 70' tower. I don't want to have to replace this thing again!
>
>Thanks,
>
>Mike, W4EF.....................
>
>
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