Hi
I do agree with Tom here. Acording to my experience the most important point
in quality of the connector is the quality of the female part of it. If the
male of UHF goes into the female firmly the connection will do fine and will
not be warm. If it goes there easily here we have a problem the connector
will be warm for sure.
Not a big science just P = R * I * I. Valid for DC and HF too !
73 !
Jiri
OK1RI
-----Original Message-----
From: owner-towertalk@contesting.com
[mailto:owner-towertalk@contesting.com]On Behalf Of Tom Rauch
Sent: Tuesday, April 03, 2001 1:21 AM
To: towertalk@contesting.com; i4jmy@iol.it
Subject: Re: [TowerTalk] Connectors
> rated for RF power well exceeding the Kilowatt. The bigger size of the
> UHF central pin connector lead to believe that a UHF connector
> withstand more current than N but this is true only at DC or in the
> lowest HAM band where mechanical precision is a less stringent matter.
Dimensions of the N are almost identical to the BNC connector. As
a matter of fact, if you remove the locking bayonet from a male
BNC it works nicely as a "quick connect" for 50 ohm N females.
Normal N connectors are rated for about 1000 watts, and they are
living on borrowed time even at 1500 watts. This is especially true if
SWR is high, or if there is moisture ingress into the connector.
I am very interested in the claims that the much smaller pin of the
N, and the much smaller spacing from the conductor to ground can
handle more current and voltage than the larger pin and larger
spacing of the UHF connector.
I am especially interested because that runs contrary to my
experience and the experience of many others that I know over the
past 30 years.
All hyperbole and conjecture aside, please explain the mechanism
that allows a smaller conductor to safely dissipate more heat, or
have less surface resistance as frequency is increased, than a
conductor several times larger.
Also, please explain the mechanism that allows a much smaller air
gap to hold off more voltage than a larger airgap.
I would be interested in the physical reason for this, and some
evidence or explanation why the mechanical holding ability of the N
is better.
73, Tom W8JI
W8JI@contesting.com
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