[AMPS] Hi Power Connectors

Maurizio Panicara i4jmy@iol.it
Tue, 21 Nov 2000 22:39:41 +0100


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 .
Also isolation is a bit meaningless parameter because 1500W @ 50 Ohms are
only 275V.
What counts, under reasonable limits, are impedance, materials, small size,
mechanical precision etc. and this is valid in all RF connectors, EIA flange
included (good inners made with berilium make a big difference compared with
lower quality ones)
For the same reason large vaacum relays for RF are rated for much smaller
currents at higher frequencies.
A 30A DC can easily drop to less than 10 A @ 30 MHz and some other non
vacuum switch, looking smaller but impedance constant and mechanically
precise, allows much more power already at 30 MHz and expecially above.
By the way, 1500W represent only 5.5 A @ 50 Ohm and both PL259 and N can
perfectly withstand it below 30 Mhz.
Power apart, N has other mechanical advantages that insure a much bigger
long term reliability than PL does.
Good cables and good connectors shouldn't be a matter to spare money but a
desiderable form of good investment.
World instead goes different and some mental habits are unchangeable in
front of anything.
Supported by the tradition to spend money in more visble devices (i.e.
expensive aluminium with lossy traps, weak but tall towers, or rigs with
miriads of leds and knobs), cheap cables and cheap connectors  have always
been a good business for traders and also a nice source of poorer results
and failures.

73,
Mauri I4JMY



----- Original Message -----
From: "measures" <2@vc.net>
To: "Steve" <ve3tu@rac.ca>; "Maurizio Panicara" <i4jmy@iol.it>
Cc: "k6uj" <k6uj@pacbell.net>; "AMPS" <amps@contesting.com>
Sent: Tuesday, November 21, 2000 8:49 PM
Subject: Re: [AMPS] Hi Power Connectors

> >
> I have put 7kW PEP through a BNC on 160m.
>
> cheers, Steve
>
> -  Rich..., 805.386.3734, www.vcnet.com/measures.
> end
>


--
FAQ on WWW:               http://www.contesting.com/FAQ/amps
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com