With 1500 watts passing through an N connector, a flat 50 ohm load gives
roughly 275 volts and 5.5 amps. A two to one SWR could raise the voltage to
roughly 400 volts or the current to roughly 8 amps, if the connector was
unfortunately situated in a voltage or current maxima.
These would fall into the range of reasonably encountered currents and voltages
in *legal* amateur stations.
How much of a safety margin? Two to one? Figure whether you are happy with 16
amperes of RF on that little N pin. Or whether you like 800 volts of volts of
RF on the gap between a BNC center conductor and sleeve.
Otherwise just understand you are running "tight" on that N connector.
I have N connectors for my 1 1/4 hard line. Wonder if W8JI has posted just how
he "machined" the hardline N connectors for UHF?
73, y'all,
Guy.
>
> From: Jan.E.Holm@telia.se
To: <towertalk@contesting.com>
> Date: 2001/04/03 Tue AM 08:12:29 EDT
> To: towertalk@contesting.com
> Subject: [TowerTalk] Re:Connectors
>
>
> Well, ofcourse UHF is perfectly fine. N is also perfectly fine.
> I guess UHF will take more power but for HF unless you do
> run a 4 by 5 at full blast N will be ok, N will take several KW´s
> on HF bands year in and year out. If one runs "serious" EME
> power on 144 MHz N is not a good idea but then again I know
> people runing 2 - 3 KW´s using N connectors with no problems.
> Also the loss or impedance deal is no issue at least below
> 400 MHz. I once years ago did measure UHF N and other
> connectors and nothing of any bigger significanse happens
> untill you move above 400 MHz so for 144 and below dont
> worry to much.
> Finaly on the installation bit. Like anything else it has to be
> done right. I dont think its any harder installing N´s then UHF´s.
> However I dont solder any more, always use crimp connectors.
>
> 73, Jim SM2EKM
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