[TenTec] OT: Lightening Protection for Openwire/Window Line

[Al Gulseth]

This gives some credibility to the OOT's (Old Old Timers) reported practice of 
tying a string to the end of the feedline for retrieval purposes and then 
tossing the feedline out the window onto the ground. That way the the 
feedline is completely outside the house in the case of a lightning strike or 
static discharge. (I've used essentially that same method in older houses for 
semi-permanent setups fed with Belden 8230 300 ohm TV ribbon.)

73, Al

On Wed July 31 2013 1:47:36 am Richards wrote:
> Interesting answers...
>
> I am wary of any solution that leaves transmission lines loose and
> ungrounded.  I have seen how lightning can arc from a disconnected cable
> across a desk and zap a radio. It my friend's SWL installation, but I
> doubt lightning cared what sort of radio it is toasting.
>
> Thus, I am skeptical bout just opening a knife switch on the wall and
> not grounding the wires in some way.  I am even a little worried about
> Joel's balanced arrestor acting alone on an unterminated (open) knife
> switch.  I would ALSO ground the two wires on a buss bar.   (See Wireman
> 857 and 858 - which I use.)
>
> 	I really like Stuart's notion of a double throw
> 	knife switch that grounds both sides when off
> 	the air.
>
> Coax enters my shack via 8 inch bulk head connectors.  I use a properly
> rated and grounded arrestor outside, and all disconnected lines are
> routed to a buss bar with extremely short RG-213 patch cables (using the
> same push on connectors Joel mentioned.)  My theory is I can disconnect
> all my antennas and ground them directly, and separately, from the
> radios. The support masts are also grounded - and all grounds are bonded
> together - using four (4),  8-ft ground rods located about 4 to 6 feet
> from each other, they are all about 6 feet from the shack coax entry point.
>
> My remote coax switch is grounded to this set of grounds, as well.  I
> switch the system to the dummy load when I close the station.  I
> disconnect the radios and patch the inside bulk head connector to the
> grounded buss bar - so any energy that gets past the outside arrestor
> (connected to the four ground stakes) is routed to the grounded buss bar
> and directed back outside, again to the four stakes.  My only concern is
> that I may have created a ground loop that causes me problems, but so
> far, no problems.
>
> As per above, I would never leave a disconnected wire or cable loose and
> ungrounded (disconnected)-- all unused lines are routed directly to the
> grounded buss bar with a very short, heavy patch cable.   I use screw on
> connectors for HF antennas, and push on connectors for the SWL and VHF
> scanner antennas as I think the screw type provide better (tighter) and
> more positive electrical connection.  (K4TAX taught me about snugging up
> connections early on...)
>
> Just My take, anyway.
>
> -------------------- K8JHR  --------------------
>
> On 7/30/2013 9:39 AM, Joel Hallas wrote:
> > While knife switches have been popular over the years, the big ones with
> > wide spacing are hard to find. My approach is to have a balanced arrestor
> > at the entrance panel and then I have 3/4 inch spaced banana plug and
> > jack between the arrestor and the line to the tuner. When I'm not on the
> > air with that antenna, it is pulled out and feet away from anything.
> >
> > The only balanced transmit level arrestors I'm aware of in recent years
> > have been from ICE and mine is one of their earlier series. Their
> > arrestor line is handled by array solutions and they now have a new
> > design
> > http://www.iceradioproducts.com/. It is also possible to use a pair of
> > coax type arrestors, but determine the voltage at that point on each band
> > due to SWR and make sure that you select arrestors that won't flashover
> > with the RF.
> >
> > I use a similar approach for coax fed antennas. I have arrestors on the
> > grounded panel and then use PL-259 push on adapters on the radio side.
> > One yank and they're all well removed.
> >
> >  _______________________________________________
>
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