[AMPS] Re: N connectors
John Fielding
johnf@futurenet.co.za
Wed, 21 Oct 1998 18:53:25 +0200
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N connectors are rated to at least 5kW at sea level. The problem come at
very high altitudes where ionisation due to the rarefied atmosphere causes
most connectors to arc over.
John ZS5JF
----------
> From: Larry Molitor <w7iuv@axtek.com>
> To: amps@contesting.com
> Subject: Re: [AMPS] Re: N connectors
> Date: Wednesday, October 21, 1998 1:48 AM
>
>
> At 09:09 10/20/98 -0000, you wrote:
> >
> >>My feeling is that a PL259 should be good to 3Kw in low SWR system -
say
> >><2:1. Although the Type N is rated to 1 Kw, I feel unhappy about
putting
> >>over 4 amps through what is a BNC as far as the inside is concerned.
>
> Ahh! N connectors, one of the things that causes me to get up on the soap
> box. Here goes....
>
> If I remember the Mil Spec right, N connectors are rated at 800 watts max
> at 150 Mhz. So are BNC's, TNC's and others. Of course that's at
> environmental conditions that I would not subject myself or my equipment
to
> by choice.
>
> I can and do use N's and BNC's interchangebly at power. You can even mate
a
> BNC to a N if you watch what you're doing. I have used (with zero
failures
> over periods of years) BNC's and N's on 2 meter EME at 1400 watts.
>
> N's are nice to use outside because they are by design extremely weather
> resistant. Next best thing to hermetic seal if PROPERLY installed. By my
> personal count, I believe there are only about 6 people in the entire
world
> that can reliably install a N connector. I, myself, have been putting
them
> on for about 30 years now and get it right most of the time. (But not
every
> time!) I have even disected commercial cables that were incorrectly
assembled.
>
> The biggest single cause of N failure is the use of the connector on
> RG8/RG213 size cables. The posterior dimensions of the connector are
sized
> to fit RG9/214 double shielded cables and as a result the clamps and
seals
> just don't work right on RG8. You can compensate for this by using the
> correct size of UV stabilized shrink tubing over the cable to make up the
> diameter difference, but it's a difficult think to get right, especially
up
> on a tower.
>
> My compromise solution: Use N's outside, UHF's inside and keep the SWR
low
> and power out legal. I don't like it much, but the biggest amp in the
world
> don't do you a bit of good if all the connectors are fried.
>
> I want to run 10 kw, but I don't have a single antenna, feedline,
> connector, or AC main that could handle even half that reliably. Maybe
when
> I get to be rich and famous.......
>
> 73,
> Larry - W7IUV
>
> --
> FAQ on WWW: http://www.contesting.com/ampfaq.html
> Submissions: amps@contesting.com
> Administrative requests: amps-REQUEST@contesting.com
> Problems: owner-amps@contesting.com
> Search: http://www.contesting.com/km9p/search.htm
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<html><head></head><BODY bgcolor=3D"#FFFFFF"><p><font size=3D2 =
color=3D"#000000" face=3D"Arial">N connectors are rated to at least 5kW =
at sea level. The problem come at very high altitudes where =
ionisation due to the rarefied atmosphere causes most connectors to arc =
over.<br><br>John	ZS5JF<br><br>----------<br>> From: Larry =
Molitor <<font color=3D"#0000FF"><u>w7iuv@axtek.com</u><font =
color=3D"#000000">><br>> To: <font =
color=3D"#0000FF"><u>amps@contesting.com</u><font =
color=3D"#000000"><br>> Subject: Re: [AMPS] Re: N connectors<br>> =
Date: Wednesday, October 21, 1998 1:48 AM<br>> <br>> <br>> At =
09:09 10/20/98 -0000, you wrote:<br>> ><br>> >>My feeling =
is that a PL259 should be good to 3Kw in low SWR system - say<br>> =
>><2:1. Although the Type N is rated to 1 Kw, I feel unhappy =
about putting<br>> >>over 4 amps through what is a BNC as far =
as the inside is concerned. <br>> <br>> Ahh! N connectors, one of =
the things that causes me to get up on the soap<br>> box. Here =
goes....<br>> <br>> If I remember the Mil Spec right, N connectors =
are rated at 800 watts max<br>> at 150 Mhz. So are BNC's, TNC's and =
others. Of course that's at<br>> environmental conditions that I =
would not subject myself or my equipment to<br>> by choice.<br>> =
<br>> I can and do use N's and BNC's interchangebly at power. You can =
even mate a<br>> BNC to a N if you watch what you're doing. I have =
used (with zero failures<br>> over periods of years) BNC's and N's on =
2 meter EME at 1400 watts.<br>> <br>> N's are nice to use outside =
because they are by design extremely weather<br>> resistant. Next =
best thing to hermetic seal if PROPERLY installed. By my<br>> =
personal count, I believe there are only about 6 people in the entire =
world<br>> that can reliably install a N connector. I, myself, have =
been putting them<br>> on for about 30 years now and get it right =
most of the time. (But not every<br>> time!) I have even disected =
commercial cables that were incorrectly assembled.<br>> <br>> The =
biggest single cause of N failure is the use of the connector on<br>> =
RG8/RG213 size cables. The posterior dimensions of the connector are =
sized<br>> to fit RG9/214 double shielded cables and as a result the =
clamps and seals<br>> just don't work right on RG8. You can =
compensate for this by using the<br>> correct size of UV stabilized =
shrink tubing over the cable to make up the<br>> diameter difference, =
but it's a difficult think to get right, especially up<br>> on a =
tower.<br>> <br>> My compromise solution: Use N's outside, UHF's =
inside and keep the SWR low<br>> and power out legal. I don't like it =
much, but the biggest amp in the world<br>> don't do you a bit of =
good if all the connectors are fried.<br>> <br>> I want to run 10 =
kw, but I don't have a single antenna, feedline,<br>> connector, or =
AC main that could handle even half that reliably. Maybe when<br>> I =
get to be rich and famous.......<br>> <br>> 73, <br>> Larry - =
W7IUV <br>> <br>> --<br>> FAQ on WWW: =
&=
nbsp; <font =
color=3D"#0000FF"><u>http://www.contesting.com/ampfaq.html</u><font =
color=3D"#000000"><br>> Submissions: =
&=
nbsp;<font color=3D"#0000FF"><u>amps@contesting.com</u><font =
color=3D"#000000"><br>> Administrative requests: <font =
color=3D"#0000FF"><u>amps-REQUEST@contesting.com</u><font =
color=3D"#000000"><br>> Problems: =
&=
nbsp; <font =
color=3D"#0000FF"><u>owner-amps@contesting.com</u><font =
color=3D"#000000"><br>> Search: =
&=
nbsp; <font =
color=3D"#0000FF"><u>http://www.contesting.com/km9p/search.htm</u><font =
color=3D"#000000"></p>
</font></font></font></font></font></font></font></font></font></font></f=
ont></font></font></font></font></body></html>
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Search: http://www.contesting.com/km9p/search.htm