Topband: OT - disconnecting coax and rotor/control cable

[David Harmon]

Rick you are so right!
I do the same thing as you do.
But....one time I made the mistake of allowing the coaxes to lay on the floor....now I have 2 holes burned through the carpet in the shack.
Won't do that again!


73

David Harmon
K6XYZ
Sperry, OK

-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Richard Schmiedt
Sent: Friday, September 7, 2018 11:36 PM
To: Gary at ka1j.com
Cc: Topband at contesting.com
Subject: Re: Topband: OT - disconnecting coax and rotor/control cable

I’ve been hit twice, in SC where we have lots of lightning.  I gave up on proper grounding techniques during a lightning storm. My shack is now optimized to ISOLATE all station equipment from the antennas, AC mains, and grounds coming into the shack when I’m not around. All the stuff coming from the outside, like antenna transmission lines are directly grounded to a buss going to outside grounding rods, this includes all rg6 lines from RX antennas. Rotator cables are detached with 8 pin cinch-jones plugs which are unplugged, and the outside ends are tied around the grounding strip to the outside. The mains for both 120 and 240V lines optimized for quick disconnect from their sockets (including the computer).  Finally the station ground is removed. All station equipment and leads are at least 2-4 feet from the ant outside inputs to the shack. 

Switches don’t work even with just nearby strikes. Isolation means no grounds around for lightning to seek. For a direct strike, all bets are off no matter what you do. 

It takes me less than 2 mins to completely isolate my equipment. I have had no problems (knock on wood) with my radio equipment over 15 years where I’ve had other TVs and electronics in the house blown up by nearby strikes. 

There are many examples of coaxial grounding strips you can use. For the F connectors I use slip on connectors. For coax, slip ons are good for low power, but I prefer to screw them on for high power.  The KISS principle is your friend ...

Good luck and my 2 cents. 

Rick
W4GE

Sent from my iPhone

> On Sep 6, 2018, at 7:14 PM, Gary Smith <Gary at ka1j.com> wrote:
> 
> Don't know where best to post this and I respect the knowledge base 
> here so I'll ask with the OT in the subject line. I'm getting to the 
> point I want to do less effort and still do things right. I had 
> lightning damage to a K3 and don't want to do that again.
> 
> What enters the house are: 
> 
> - RX antenna controller cables One with 5 wires, one with 6.
> - Antenna rotor cable 6 wires. 
> - The remote coax switch 7 wires.  
> - Two coax going to the amplifiers.
> - Two RG-6 coax going to the Rx antennas.
> 
> I would also like to separate the 120 V strips at the same time
> 
> What I would like to do... is have one or two switches to flip that 
> will allow disconnect of all of this.
> 
> As it is now, I have to unscrew each coax each time I close the shack 
> and re-attach the next time I'm in the shack. I made molex connectors 
> for the Rx controller cables, have not yet done that with the rotor 
> cable nor the remote coax cable. I unplug the power to the terminal 
> strips
> 
> I was thinking of perhaps using relays (I have a lot of SS relays but 
> don't think they would be usable in this endeavor.
> Maybe relays like in the old SB-220 where there were many individual 
> relays activated at the same time, would work for control/rotor 
> cables. But I wonder if the air gap in such a relay would be 
> sufficient to be a barrier come another lightning issue.
> 
> I have several vacuum & heavy contact air gap relays that could do the 
> job for the coax. I also have some substantial relays I could use for 
> the power cords involved.
> 
> If I were to have all this in one
> enclosure, it would be nice to get up, flip a few switches and walk 
> away knowing my station is truly disconnected. At this point I have 
> time to do anything, and I like making things, but only if it's worth 
> the time.
> 
> Thoughts?
> 
> 73,
> 
> Gary
> KA1J
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