That's the way standard (fractional) drill sizes are measured although I
doubt they really are accurate to 4 decimal places. They would need to
be new, or precision sharpened to cut a hole to match the drill size
within 4 or 5 thousandths. The way most of us sharpen drills makes them
tend to run off center and drill an over size hole. <:-))
73
Roger (K8RI)
On 3/7/2015 6:03 PM, Randy wrote:
Thanks for clearing that up, Jim.
FFS. just HOW cold does it get there? In degrees, F?
You measure holes down to 1/10,000th of an inch?
73
Randy
KZ4RV
On 3/7/2015 12:31 PM, Jim Thomson wrote:
Date: Fri, 06 Mar 2015 14:26:36 -0500
From: "Roger (K8RI) on TT" <K8RI-on-TowerTalk@tm.net>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Water in Conduit... the fix
### ...
If u use a weep hole,
use the bare min.. like one...maybe two at most...and no bigger
than .15625 dia,
( five sixteenths). .125 inch or less is usually not big
enough..and can become plugged with debris.
###### oops.... I meant to say 5 / 32 of an inch = .15625 inch
diam.
Jim VE7RF
If you must use weep holes, I'd keep them very small. In many areas
5/16ths is far too large! The reason is bugs, Wasps, and spiders. We
seem to have gained a massive increase of paper wasps, Mud Dobbers, and
those tiny nasty tempered Yellow Jackets over the past few years.
Yellow jackets seem to prefer cooler locations as in the ground and
under garage floors. Mud Dobbers and Paper Wasps like enclosed spaces
like the tuning unit for my Hy-Gain AV640 (
http://www.rogerhalstead.com/ham_files/AV-640/AV640.htm ) 6th photo
down. Text gives explanation. The little, stock drain hole was still
large enough for them to get in. RF killed a few, causing others to
gang up on the threat, causing a massive mess.
Last summer I removed nearly a dozen Paper Wasp nests from our 200 X
200' lot. Some were larger than a football.
I opened the small 8' garage door on the West end of the South side of
the shop to find a new nest of unhappy wasps. Only got stung twice
before I got the door closed.
Several years ago, the whole neighborhood had more than that per 100' X
200' yard.
73
Roger (K8RI)
On 3/6/2015 1:00 AM, Jim Thomson wrote:
Date: Thu, 05 Mar 2015 08:22:58 -0600
From: Patrick Greenlee <patrick_g@windstream.net>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Water in Conduit...
Those of you unable to keep water out of your conduit have my sympathy.
I know how irritating it could be. If your conduit is assembled
properly
and doesn't leak leaving the airborne moisture as your target then put
desiccant bags in the conduit and plug the ends of the conduit where
the
cables enter/exit. Various ways to plug include duct tape, spray foam,
wadded up paper coated with silicon caulk or...
Patrick NJ5G
#### .....or use DUCT SEAL. Available at any home depot...in the
electrical dept.
Comes in 1lb packages. It?s the Standard to use to seal conduit
ends. At the telco
I worked at, they had it in 10 lb bags. Duct seal works
great..since its like kids plastercine.
Pliable, and easily stuffed in there, and molded to fill all the air
gaps. Easily removed when
it comes time to add one more cable... or remove a cable.
## leaving conduit open is just asking for trbl. Even if the
conduit terminates inside your
basement, or terminates inside a metal or plastic nema box, you
still use duct seal.
## In nema boxes out doors, or stuff like remote ant switch boxes,
etc, put a lot of
desicant inside..aka.. silica gel. Silica gel absorbs up to 40% of
its weight in water.
Seal the boxes up air tight..then with silica gel inside, they will
be bone dry. Change
the silica gel out once every year. If a box has power to it, a
pair of those metal
finned resistors and some voltage through em 24-7 also works very
well. Just a bit
of constant heat will ensure the box remains dry..and the silica
gel absorbs the rest.
2nd resistor is for redundancy.
## Im not a fan of metal nema boxes, since they are more prone to
condensation forming
on the inside. Some will use weep holes on the low point to let
water out. If u use a weep hole,
use the bare min.. like one...maybe two at most...and no bigger
than .15625 dia,
( five sixteenths). .125 inch or less is usually not big
enough..and can become plugged with debris.
## If the weep hole is made too big, the silica gel inside will
begin to try and absorb moisture
from the outside, high humidity ari..like rain and fog, high
humidity condx, etc.
## Install large diam conduit ..like the 4 inch stuff....and forget
putting holes on the bottom side of it,
Utilities don?t. Make sure its all bone dry b4 gluing the sections
together.
Jim VE7RF
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73
Roger (K8RI)
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