[TowerTalk] [BULK] - N-Connector & Belden 9913F7

[Dubovsky, George]

Steve, Fred and the list,

No question, the special pins are the best way to go, but if I needed
one on a Saturday afternoon, I would not hesitate to drill one out. It
certainly does not require CNC machinery or any exotic tooling to
accomplish the task,  for one VERY important reason: the manufacturer
has already provided a pilot hole exactly where you need it, right on
the center line of the pin, and pre-drilled to the correct depth.

If you attempt to drill a slightly larger hole following a pilot hole,
the larger hole will be on the same central axis as the pilot, even if
you are performing the operation in a lathe and the pilot is off-center
of the lathe axis. The unequal cutting forces from an off-center drill
quickly steer it back to the pilot axis - this is absolutely true for
short holes and small diameter drills (like this discussion), and the
effect is still dominant for large drills and deep holes.

So how to do it in practice? A drill press and a small vise to hold the
pin from rotating would work every time. A drill press and holding the
pin against the drill press table with a small pair of pliers should
work darn near every time. Either the work will shift slightly, or the
drill will flex slightly, but the resulting hole WILL be in the center.
If you have a good trigger finger, you could likely use a variable speed
hand drill, a pair of non-marring pliers, and a dose of luck to drill
out the pin.

Another one of those things that's easier done than said...

73,

geo - n4ua

> -----Original Message-----
> From: towertalk-bounces at contesting.com [mailto:towertalk-
> bounces at contesting.com] On Behalf Of Steve Katz
> Sent: Friday, September 23, 2005 1:20 PM
> To: 'Fred Mott'; towertalk at contesting.com
> Subject: Re: [TowerTalk] [BULK] - N-Connector & Belden 9913F7
> 
> Type Ns with special "hogged out" (milled out) center pins are readily
> available from a number of sources including The R.F. Connection in
MD,
> who
> almost always has them in stock for immediate shipment.  I just use
those.
> Tinning and filing the center conductor probably works, but is awfully
> labor-intensive.  "Drilling" a hole in the center pin isn't going to
work
> using conventional tooling -- this is a really critical process and
> requires
> a CNC machine and a fixture to clamp the pin.  The resulting milled
out
> pin
> has *very* thin walls, if you "miss" by a few thousandths of an inch,
> you'll
> break through the wall and have a pin headed for the trash can... -
> WB2WIK/6
> 
> -----Original Message-----
> From: Fred Mott [mailto:fredmottcpa at earthlink.net]
> Sent: Thursday, September 22, 2005 5:34 PM
> To: towertalk at contesting.com
> Subject: [BULK] - [TowerTalk] N-Connector & Belden 9913F7
> 
> 
> How do you install a N-Connector onto a Belden 9913F7 coax.  


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