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Re: [TowerTalk] Quick Disconnect Suggestion

To: "'Jerry'" <>, "Tower Talk" <>
Subject: Re: [TowerTalk] Quick Disconnect Suggestion
From: "Dick Green WC1M" <>
Date: Wed, 10 Jun 2009 23:55:28 -0400
List-post: <">>
Good question. It's not easy to answer if you have a lot of cables, like I
do. I think my current count is in the neighborhood of 30 cables. Here are
some pictures of how I do it:

You can view the large version of the pictures by clicking on the View Album
button, then play the slide show in full screen mode.

My SPG consists of two bonded metal cabinets on the side of the house, and
it's not practical to disconnect the cables there -- the boxes are filled to
the brim with cables and several different kinds of suppressors. There's no
place to put connectors and it would be difficult to wade through all the
wires to get to them. Also, it takes time to unscrew the cabinet doors, and
that's not good if lightning is approaching. Finally, there wouldn't be much
physical separation between the cable ends unless I draped them outside the
boxes in the rain. So, the quick-disconnect panel is inside the house.

The cables originally entered the house through the sill to the ceiling
above the basement, then through a hole in the floor to the shack. I just
pulled the cables down to the utility closet I built for the amps and
automatic antenna switching equipment (all that is driven by a homebrew
Windows app.)

Then I built the patch panel you see in the photos. It's modular and can be
expanded if needed. The holes in the panels are pre-punched by the
manufacturer, though I had to drill out the PL-259 holes (they were D-shaped
for a different 5/8" connector) and make my own rectangular holes for the
Cinch-Jones plugs.

- All of the cables from the outside come down from the ceiling and into the
patch panel, which sticks out from the wall a few inches. All of the cables
coming down through the floor from the shack attach to the outside front of
the panel. They can be quickly disconnected and pulled several feet away
from the panel.

- The row at the top has six coax cables, with enough room for 12. The panel
uses long female barrel connectors, and each incoming and outgoing cable
pair has male PL-259 connectors (one attaches inside the panel from the
back, and the other attaches to the front of the panel.)

- The next row down has F-F DB-9 connectors for two SO2R switches and a
stack match (with room for up to 16 cables). I've since replaced this with a
panel identical to the top one with 8-pin mic connectors, same as on most
ham transceivers. The DB-9 connectors wouldn't stay connected under the
weight of the cables, and I had problems using screw posts. It was difficult
to get the parts aligned correctly and the screw posts often had to be
turned with a small screw driver, even though they're supposed to be
turnable by hand. It was too time consuming, so I changed to the mic
connectors. So far, the mic connectors are working well. The cables coming
in from outside are soldered to the pins on the back of male socket
connector. It was important to use strain relief on each cable to make sure
there would be no strain on the solder joints when the patch panel is swung
away from the panel for maintenance (all the panels are hinged.) I also used
heat shrink tubing to protect the solder joints. It wasn't easy to solder
all eight wires to the female connectors, but I managed. The connector
provides strain relief.

- The next row down has room for 16 F-F DB-25 connectors. My three 16-wire
SteppIR control cables connect here, and an 8-wire cable for a
remote-control motor on a crankup tower (Could have used a connector with
fewer pins, but the cable already had a DB-25 on it.) I've since moved the
stack match cable to this panel because it needs 9 wires and the mic
connectors only provide 8. Just like the top row, the F-F connector in the
panel allows the incoming and outgoing cables to use standard male DB-25
connectors and just plug into the panel. For some reason, it was easier to
align the screw posts on the DB-25 connectors, and I'm able to use the
hand-tightened posts to screw down the connectors and removed them. It goes
quickly and easily.

- The next row down is a blank panel I fabricated for two female-female F
connectors for satellite TV (one cable happens to enter the house through
the SPG box and the other goes into the shack.) There are three F-F telco
connectors for three phone lines I have in the shack. Then there are three
6-pin Cinch-Jones connectors for my three TIC rings (the SteppIRs are
stacked on TIC rings), plus a spare. In this case, the incoming wires are
soldered onto the female connector pins. The conductors are quite heavy, so
I didn't use strain relief. I did use heat shrink on them, however. The male
connectors for the outgoing cables have built-in strain relief.

- The next row down is another home fabricated panel that has five 8-pin
Cinch-Jones connectors, one for a 4-square controller, two for rotors and
two spares.

Note that the 6-pin and 8-pin Cinch-Jones connectors are the heavy-duty 2400
series. The lighter duty 300 series didn't have matching panel mount
connectors for the 8-pin. I like the Cinch-Jones connectors best for this
application, but they're not practical for more than 8 or 9 conductors.

In addition to the patch panel, the two gray boxes to the right of the patch
panel contain AC quick disconnects for the two AC circuits that go into the
shack. As is visible in the photo, I can disconnect AC to the two amps at
the wall-mounted receptacle. There are a couple of DC wall warts feeding the
network switch and beverage reversing relay, DC end of which I can pull at
those devices.

This setup lets me disconnect every wire from outside the house that goes
into the shack. During the summer, everything is normally pulled, except the
shack AC, satellite TV and telco lines. I plug in the radio gear only when
there's a contest, some very rare DX or I need to do some testing. There's a
separate patch panel in the stairwell behind my entertainment center where I
can disconnect the C-band dish, rooftop OTA antennas, the Dish satellite
dish and a telco line. Whenever there are thunderstorms in the forecast, and
whenever we leave the house overnight, *everything* gets disconnected.

Oh yeah -- every conductor from both tower complexes is connected to a
suppressor at both the tower and SPG. The ground system at the towers and
house is extensive as well.

One $10,000+ lightning disaster was quite enough for me.

73, Dick WC1M

> -----Original Message-----
> From: Jerry []
> Sent: Wednesday, June 10, 2009 10:41 AM
> To: Tower Talk
> Subject: [TowerTalk] Quick Disconnect Suggestion
> What do you use for your rotator, antenna switch, etc. connectors at
> your SPG boxes?  I like to disconnect my antenna feed lines and control
> lines when thunderstorms approach, etc.  I've looking for ideas with
> respect to SPG box connector and the line connector plugging into the
> box.  Hope that makes sense!  I have use a mike connector and a Cinch
> Jones, but these seem to have problems over time.  Thanks for your help.
> Jerry France
> K7LY


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