[BC] AM transmitter lightning sensitivity issue

[DHultsman5 at aol.com]

In many cases of older tower installations, many times the origional guy 
wires may have been grounded thru the deadman in concrete. Over the years the guys 
the deadmen in the concrete have rusted and the guy wires are not grounded at 
the ground end of the guys.

I had a station with a solid state transmitter that would shut down when a 
thunderstom was in the area.  The sun could be shining..  I added a static drain 
still the transmitter would VSWR during the storm or static build up periods.

Finally on day after going back to the old tube-type transmitter around 
twilight in the evening I saw some sparks between the top insulators on the tower.  
I watched it for a while as the tube transmitter would just continue to stay 
on the air.  I noted that the next insulator would arc a couple of times 
before the three insulators next to the tower arced.   

In a discussion with an older engineer, he suggested that the static was 
building up on the guy wires and since the path to ground at the ground end of guy 
wire was essentially not grounded properly.  The static would build up to a 
point that it would jump the insulators next to the tower.  He suggested that 
we use copper wire and new rods at the base of each anchor to ground the guy 
wires.  

It didn't totally stop the tripping of the solid state 100% but we could 
usually operate the transmitter until the storm was on top of us.

Check your guy wire grounds.

Dave

> On Wednesday 21 May 2008 01:41 pm, Gregory Muir wrote:
> > Within my station group I have a Harris Gates Five AM transmitter which 
> > exhibits an unusual sensitivity to local lightning storm events.  Upon the
> 
> > appearance of a storm, the transmitter will begin to automatically lower 
> > it's output power through the power adjustment range with each lightning 
> > strike until it finally goes off the air after reaching the lowest power 
> > setting.  It is obvious that the unit sees VSWR events which causes it to 
> > react.  But what is interesting is that it will react to the same events 
> > even when the storms are 5-10 miles distant from the site with similar 
> > results.     
> 




**************
Get trade secrets for amazing burgers. Watch "Cooking with 
Tyler Florence" on AOL Food.
      (http://food.aol.com/tyler-florence?video=4&
?NCID=aolfod00030000000002)