[TowerTalk] Length of Mast

Sun Jun 1 23:53:03 EDT 2003

Can't say I'd call the fiberglas tubes that the bronze tapes slide in
'shielding', the tubes being non-metalic.  But, yes mine doesn't show as
much precip static as my aluminum yagi did.  Don't know why.

I can't speak to stacking Steppirs.  Hard to decide on proper spacing etc.
I don't know if anyone has tried stacking yet.

When I shut down, at night or for a thunderstorm, I retract the metalic
portion of the antenna into the stepper box at the boom.  Dunno if that
provides any protection, but I feel better about it...

Gil, W1RG

----- Original Message ----- 
From: "Mark Pride" <mpride at us.ibm.com>
To: <towertalk at contesting.com>
Sent: Sunday, June 01, 2003 10:29 PM
Subject: Re: [TowerTalk] Length of Mast

>
>
>
>
> In all this discussion regarding grounded towers and multiple grounded
> yagis that appear to dissipate lightening strikes or protects better than
a
> single tower with few yagis.  I recently heard that the new Steppir
Antenna
> with its insulated (shielded) elements tend to reject the electrostatic
> build up during rain/snow storms (rain static or snow static) during
> intense downpours (S meters go to 20 to 40 dB over S9) wiping out the
band.
> Having a stack of these I would persume would not be very effective when
it
> comes to this lightening dissipation action found with grounded elements.
> Any comments group?  At first I thought the new Steppir might be the
answer
> to a problem that affects us all during these storms (that tend to show up
> during contests) - rain static rendering the band useless, unless you
> listen on the lower antenna of a stacked array.
>
> Regards,
>
> Mark, K1RX
>
>
> K3BU at aol.com@contesting.com on 06/01/2003 09:45:16 PM
>
> Sent by:    towertalk-bounces at contesting.com
>
>
> To:    towertalk at contesting.com
> cc:
> Subject:    Re: [TowerTalk] Length of Mast
>
>
>
> In a message dated 6/1/03 6:16:41 PM Eastern Daylight Time,
> shr at medinaec.com
> W0UN writes:
>
> >
> >   From MY personal experience and comments made by others with similar
> >  experiences I firmly believe that a naked tower, with or without a
> lightning
> >  rod tends to attract lightning.   But that a well grounded tower with
> lots
> >  of grounded Yagi elements tends to reduce or virtually eliminate
strikes
> >  in the immediate vicinity.   YMMV!
> >
>
> MMDNV!
> Back in Toronto it really striked me when I upgarded from 65 ft tower with
> TH6 to 110' Bertha with 3 el. full size stretched Telrex 40m beam or pair
> of 62
> ft Razors. With old tower I was hit directly and had appliances
selectively
> burned around the house twice within couple of years. After I put up
Bertha
> with
> big antennas, I was NEVER hit over 10 years. I had 2m Ringo Ranger on the
> top, so if I was hit with "overlooked" strike, that thing and connected 2m
> junk
> would have been fried.
>
> Bertha sits in 11' foundation tube with good contact via bearing ring and
> (bearing) ball at the base. Before I pored the concrete, I hammered bunch
> of
> water pipes (one came to the surface and I used it to water the grounds
> before the
> contests :-) into the bottom of the foundation hole and welded them to the
> foundation tube. It may be purely luck (statistically should not be) but I
> was
> also "forced" to believe that big antennas "scare" the lightning away and
I
> join other big antenna nuts in singing the praise for big antennas.
>
> I think what is happening, that tower with large grounded elements beam
> serves as a "drainage" capacitor for the immediate semi spherical area,
> drains the
> charge in vicinity and prevents the formation of the leader and the
> following
> big vaporizing strike. Sort of like an umbrella for lightning effect.
> While
> the pointy bare tower has hardly any capacitance (looking from the top)
and
> looks "attractive" to lightning for starting the leader and strike. This
> might be
> the next best thing to do (if can't go high and big), use classic
lightning
> arrestors and grounding trying to start and create the path for lightning,
> rather than letting it hit structures like houses and barns.
>
> Another proof of "umbrella effect" is that when you have static from the
> rain, the top antenna is useless, 20 over 9 QRN. Bottom antenna in the
> stack is
> DEAD quiet.
>
> BTW our nasty next door neighbor was once hit twice within 3 minutes and
we
> got some appliances fried via underground electrical wiring surge (no
tower
> here). So what we need now is to pass the law requiring hams to have big
> towers
> and antennas and to provide the protection to the neighboring citizens.
All
> those no antenna communities are horibly exposed to lightning damage.
>
> Yuri, K3BU, VE3BMV
>  I don't have a degree in lightning sciences and I don't sell antennas
(yet
> :-)
> _______________________________________________
>
> See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
> Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with
any
> questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
>  http://lists.contesting.com/mailman/listinfo/towertalk
>
> _______________________________________________
>
> See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
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