[amsat-bb] Preamps and Circular Polarization Switch.

[Ray Hoad]

When you make your connection to your driven ground at the base of your
tower, make all your ground wires are as straight and as short as possible.
Lightning considers any 90 degree bends in the grounding wire (made to make
the installation look neat) as a high impedance in the path to ground.
Lightning may find a another way with less impedance that you do not want it
to follow.  In my 37 years with a utility company, I have found that the
straighter and shorter the ground wire the better. I have seen a lot of very
expensive equipment thrown into the trash can because of ground wires with
lots of bends or because they were unnecessarily long.

Ray Hoad
WA5QGD

-----Original Message-----
From: AMSAT-BB [mailto:amsat-bb-bounces at amsat.org] On Behalf Of Glenn Little
WB4UIV
Sent: Monday, June 29, 2015 8:13 PM
To: J Bennett; 'Jim Bennett'; 'Amsat'
Subject: Re: [amsat-bb] Preamps and Circular Polarization Switch.

Sounds like you have done your homework.
I wish more would do the same.
I did lightning damage mitigation in a previous job.
I had some professionals tell me I did not know what I was doing.
After the third direct hit to a commercial tower and the replacement 
of all strobes the tower took no more damage causing hits.
Sometime later my boss directed me to return to the site and report 
on my findings.
All of the recommendation, that I was told by the professionals that 
I did not know what I was talking about, were implemented.
These included an aero spike, additional grounding and bonding of 
grounds to existing tower and structure.

If you were to add static dissipators to your tower, you might be 
able to dissipate the energy before it reached strike potential.

73
Glenn
WB4UIV



At 08:53 PM 6/29/2015, J Bennett wrote:
>I took a direct hit.  It disintegrated my 2m/70cm vertical.  It was 20 foot
>long.  Now it is in 5 pieces in various length and the neighbor's lawn has
>many piece of the radome. The tower is grounded with three grounding rods
>that are connected to the service entry point on the garage.  That saved 6
>different radio from any damage. It took out a power supply that wasn't
even
>connected to the antenna that took the hit.  I have polyphaser lighting
>protection on all antennas.  It has been up for 20 years and this is the
>first major damage.
>
>-----Original Message-----
>From: AMSAT-BB [mailto:amsat-bb-bounces at amsat.org] On Behalf Of Glenn
Little
>WB4UIV
>Sent: Sunday, June 28, 2015 10:10 PM
>To: Jim Bennett; 'Amsat'
>Subject: Re: [amsat-bb] Preamps and Circular Polarization Switch.
>
>Number one on the list is a good tower ground bonded to the single point
>service entrance ground at the house.
>MIL-HDBK-419 addresses this very well.
>When this is followed, you will have very minimum problems, unless, you
take
>a direct strike.
>This can be minimized with static dissipators.
>When was the last time you saw a FAA communications tower that took a hit
>with any damaged equipment??
>
>73
>Glenn
>WB4UIV
>
>
>
>At 08:27 PM 6/28/2015, Jim Bennett wrote:
> >Hey guys.
> >
> >
> >
> >I just took a lighting strike the other day.  Wipe out the big stick in
the
> >air.  Also took out one preamp and possible a circular polarization
switch
> >on the sat antennas alone with both PCs that I had, a power supply, plus
my
> >network.  The pair of KLM appear ok.  So I am going to redo my tower
>layout.
> >New coax(probably hard line), new preamps, new cp switch and new control
> >cable to the preamps and CP switches. Rotor cables appear good, but will
> >check to make sure.
> >
> >
> >
> >I put this system together about 20 years ago.  So I am starting out
fresh
> >trying to find the stuff.  Is Lanwear amps still available?  If not, what
>is
> >the next best. Are there any shelf available CP switches.  The ones I
have
> >were on the antennas when purchased.  And they appear home built.
> >
> >
> >
> >Any suggestions are appreciate.
> >
> >
> >
> >Jim
> >
> >Ke4kol
> >
> >
> >
> >_______________________________________________
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> >to all interested persons worldwide without requiring membership.
> >Opinions expressed
> >are solely those of the author, and do not reflect the official
> >views of AMSAT-NA.
> >Not an AMSAT-NA member? Join now to support the amateur satellite
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>
>---------------------------------------------------------------------------
>Glenn Little                ARRL Technical Specialist   QCWA  LM 28417
>Amateur Callsign:  WB4UIV            wb4uiv at arrl.net    AMSAT LM 2178
>QTH:  Goose Creek, SC USA (EM92xx)                      SBE ARRL  TAPR
>"It is not the class of license that the Amateur holds but the class
>of the Amateur that holds the license"
>---------------------------------------------------------------------------
>
>_______________________________________________
>Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available
>to all interested persons worldwide without requiring membership. Opinions
>expressed
>are solely those of the author, and do not reflect the official views of
>AMSAT-NA.
>Not an AMSAT-NA member? Join now to support the amateur satellite program!
>Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb

---------------------------------------------------------------------------
Glenn Little                ARRL Technical Specialist   QCWA  LM 28417
Amateur Callsign:  WB4UIV            wb4uiv at arrl.net    AMSAT LM 2178
QTH:  Goose Creek, SC USA (EM92xx)                      SBE ARRL  TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"
--------------------------------------------------------------------------- 

_______________________________________________
Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available
to all interested persons worldwide without requiring membership. Opinions
expressed
are solely those of the author, and do not reflect the official views of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb