Like Tom says, anyone that hasn't blown an N connector hasn't run high
power through them for a long period of time. The typical failure of N
connectors
is from the heat generated at the junction of the male and female center
connection.
The heat will cause the female connector to loose tension which creates more
heat
until it fails totally. The RF current at 1.5 kw is 6 amps which is equivalent
to 2 to
3 times that at DC values. Would you consider running 20 amps through a
connector
with that size pin? I have used 259s for HF for many years of good service with
proper water proofing. If you are concerned about impedance bumps go with C
connectors or the 7/16 style.
Tom Rauch wrote:
> > I believe it.
> > For a few minutes, I've done tests with N up to 6 Kw @ 100 MHz (continuous
> > carrier) with no failures or damages. This is possible with properly
> > installed N connectors althought I wouldn't anyway raccomend to use more
> > than 800 W @ 100 MHz with this type of connector. Up to 30 MHz there is
> > instad a wide margin when using an N at 1500W. Connection pin size is not
> > all that matters since allowable RF current is different than a mere DC
> > rating. PL259/SO239 is a bit awful under this perspective and one
> > shouldn't be misleaded by its size assuming the manageable power is larger
> > than that of N, at least above 30 MHz .
>
> I can easily blow N connectors out. When I replace them with less
> expensive easier-to-install UHF connectors of good quality, I never
> have connector problems. At HF, N's are good to 1500 watts or so
> if SWR is low. Hardly a "high-power" connector by anyone but a
> QRP club members standards. Teflon UHF's will take almost ten
> kW without problem in the same situation.
>
> I'd never use an "N" connector, unless it is an impedance critical
> system or a system above maybe 250 MHz. The N has the same
> approximate internal dimensions as a BNC, no matter how you
> install it.
>
> As a matter of fact if you remove the bayonet ring from a male
> BNC, you can use it as a quick disconnect connector for N
> females.
>
> 73, Tom W8JI
> w8ji@contesting.com
>
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