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
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