Re: Best brand coax and F connector for HD cable?

["G-squared" <stratus46@xxxxxxxxx>]

 Ed Nielsen wrote:
 > From a leading engineer in the CATV industry:  "We did a scientific
 > research for a year on CPD and contact interfaces, the report shows
us
 > that it is very important to break through the oxide layer to
prevent a
 > non-linear behavior in contact surfaces. The torque varies with the
type
 > of plating used on the F-connectors.
 >
 > Finger tight is not tight enough to break through the oxide layer,
and
 > due to temperature cycles it will loosen up after a while.
Especially
 > in the neighborhood of the subscribers and RF output of the node it
is
 > important, (the effect of a loose or bad connection is the biggest
at
 > those points) to have proper contact interfaces.
 >
 > CPD - This phenomenon, also known as Common Mode Distortion, is
 > generally the result of age and corrosion in the cable plant
connectors.
 >   This non-linear function is commonly caused by oxidation of metal
 > surfaces, creating a point contact diode.  Should the diode effect
occur
 > on the ground portion of a connector, common mode distortion and
ingress
 > are likely.  The effect that this diode phenomenon causes is
observed as
 > difference products in the return plant, and can be caused by one or

 > more faulty connectors.

What you're saying here is what I tell everyone who runs ANY kind of
signals. The ground is at least as important (I believe more important)
as the actual signal feed.

 > In general, interfering products will be observed at harmonic
intervals
 > of 6MHz throughout the return plant band.  Sidebands of this will
tend
 > to raise the apparent noise floor.  Because common mode distortion
is a
 > non-linear effect, slight variations in the point diode structure
due to
 > temperature, humidity, wind velocity, etc. have a significant impact
on
 > the interfering levels observed."
 >
 > Manufacturers and the engineering community in the CATV industry
 > recommend they be tightened to 30-in/lbs.  The best that can be
achieved
 > by hand is less than 13.
 >
 >
 > CIAO!
 >
 > Ed N.

Everything you say squares with what I have worked with in commercial
TV. On my outdoors connectors I use clear silicone heatsink (NOT
bathtub silicone !! ) grease on the connectors before snugging them up.
The grease prevents oxygen and water from corroding both the center
conductor and the ground connection. The current antenna is 15 months
old and doing fine so far. My cable of choice is Belden 1694A though
their 1505 RG-59 is nearly as good loss-wise as the lesser brands RG-6.
Yes, we use both types at work from analog NTSC and PAL to digital SDI
(serial digital) and uncompressed HD SDI.

GG