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[TowerTalk] Re: Tower Talk Digest V2 #217

To: <towertalk@contesting.com>
Subject: [TowerTalk] Re: Tower Talk Digest V2 #217
From: W6MR@pacbell.net (Joe Clement)
Date: Mon, 14 Jun 1999 07:55:39 -0700
I have installed several KT34 & XA in rain and heavy snow conditions. Snow
and ice were the only times the swr changed.
I do use poprivets on the shorting straps. The straps around the capacitor
tubes I silicone. It sounds like you had a very early one or the vent holes
in the capacitor tube in the center were down instead of up. The outer tubes
used to have vent holes, but there was a mod to seal them.

73 Joe W6MR
J & J Antenna Service
-----Original Message-----
From: Bob Smith <na6t@mcn.org>
To: towertalk@contesting.com <towertalk@contesting.com>
To: <towertalk@contesting.com>
Date: Sunday, June 13, 1999 9:11 PM
Subject: [TowerTalk] Re: Tower Talk Digest V2 #217


>
>>From personal experience,  I live in Fort Bragg, California (approx 1/4
>mile from the ocean) were we get lots of rain, you won't be very happy with
>the KLM KT-34XA or A in a wet climate.  During the dry months I could count
>on a 1.5 to 1 swr on all bands.  However, in the fall and winter I would
>loose at least ONE band in the rain, not the same band all the time, but
>.......
>
>If I wanted a Dummy load, it was great (at 5 or 6 to 1 swr)
>
>I'd be looking for a better tri-bander than the KLM.
>
>Bob Smith
>NA6T
>
>
>
>At 11:48 PM 6/13/99 -0400, you wrote:
>>
>>Tower Talk Digest        Sunday, June 13 1999        Volume 02 : Number
217
>>
>>
>>
>>In this issue:
>>
>>    [TowerTalk] Fw: BOUNCE towertalk@contesting.com:  taboo header:
>>/^cc:\s*.+/i
>>    [TowerTalk] Hard Line
>>    [TowerTalk] ZL-Special
>>    [TowerTalk] ZL-Special
>>    Re: [TowerTalk] Force12 C-3 and Omni-VI+ Static Build-up
>>    [TowerTalk] Channel Master
>>    Re: [TowerTalk] ZL-Special
>>    Re: [TowerTalk] ZL-Special
>>
>>See the end of the digest for information about towertalk-digest
>>
>>----------------------------------------------------------------------
>>
To: <towertalk@contesting.com>
>>Date: Sun, 13 Jun 1999 07:17:52 -0500
>>From: "Michael D. Ihry" <mihry@argontech.net>
>>Subject: [TowerTalk] Fw: BOUNCE towertalk@contesting.com:  taboo header:
>>/^cc:\s*.+/i
>>
>>- ----------
>>> From: owner-towertalk@contesting.com
>>> To: n5kb@contesting.com
>>> Subject: BOUNCE towertalk@contesting.com:  taboo header: /^cc:\s*.+/i
To: <towertalk@contesting.com>
>>> Date: Saturday, June 12, 1999 6:54 PM
>>>
>>> >From n5kb  Sat Jun 12 19:54:46 1999
>>> Received: from hh.tmx.com (hh.tmx.com [207.204.194.1])
>>> by contesting.com (8.9.1a/8.9.1) with ESMTP id TAA28325
>>> for <towertalk@contesting.com>; Sat, 12 Jun 1999 19:54:45 -0400 (EDT)
>>> Received: from localhost (aa6eg@localhost)
>>> by hh.tmx.com (8.8.5/8.8.5) with SMTP id QAA06612;
>>> Sat, 12 Jun 1999 16:54:38 -0700
To: <towertalk@contesting.com>
>>> Date: Sat, 12 Jun 1999 16:54:38 -0700 (PDT)
>>> From: Pat Barthelow <aa6eg@hh.tmx.com>
>>> To: thompson@mindspring.com
>>> cc: towertalk@contesting.com
>>> Subject: Re: [TowerTalk] More KT 34XA problems
>>> In-Reply-To: <000701beb514$7810e8a0$416256d1@default>
>>> Message-ID: <Pine.LNX.3.96.990612164124.6597A-100000@hh.tmx.com>
>>> MIME-Version: 1.0
>>> Content-Type: TEXT/PLAIN; charset=US-ASCII
>>>
>>> Hi Dave,
>>>
>>> We at N6IJ, recently upgraded our KT-34XA with a kit that KLM supplied,
I
>>> think for about $50.00.  We have not erected it yet, so have no SWR
data.
>>> The new kit also supplied small tubing extensions to install, and bring
>>it up to
>>> new dimensions shown in the upgrade kit diagrams.  It had the newer
>>> polyethelyne (blue) end caps for sealing the capacitors, and new
>>capacitor
>>> tubes that did not have drain holes.
>>> They had us drill a small hole on the top side  of the inner tube of
>>> each capacitor in order to accomplish what the exterior holes formerly
>>> did. The inner hole is sealed (mostly) from the immediate outside
>>weather,
>>> while allowing pressure equalization into the capacitor, which has to
>>> occur by the air passageway to the outside,traveling the length of the
>>> inner tubes through their open ends some distance away.   Apparently the
>>> KT-34XA is EXTREMELY sensitive to ANY water entering the tubular
>>> capacitors.  It is also a real bear to disassemble, clean, repair and
>>> weatherseal, though we are looking forward
>>> to adding it to our antenna farm and compare with it's bretheren and
>>> cousins...
>>>
>>> 73, DX, de
>>> Pat, AA6EG/N6IJ;
>>> aa6eg@hh.tmx.com
>>> 599 DX Drive, Marina CA 93933
>>> "The Contest Station from the Government"
>>>
>>> On Sat, 12 Jun 1999 thompson@mindspring.com wrote:
>>>
>>> >
>>> > The KT 34 XA has been sitting just above the roof for two months now
>>after
>>> > completing the re-capping.   SWR is below 1.3 on 20 and 10 and 2:1 on
>>15.
>>> > Never could get 15 below 2:1 and sigs are often louder with the 40
>>meter
>>> > beam 9 feet above.  Looks like interaction.
>>> >
>>> > But I have been working DX with no problem on 40, 20, 17, 15, 12, and
>>10 so
>>> > I decided to plan on cranking it all back up for this year.   On
>>Thursday we
>>> > had the first rain fall in three months (over an inch) and I noticed
>>the SWR
>>> > went up from 1.3 to nearly 3:1 on 10 and SWR crept up some on 15.  As
>>soon
>>> > as the WX dried up the SWR went back down.   Does anyone know how to
>>keep
>>> > the water out of the caps on 10?   I have the drain holes down as per
>>the
>>> > manual and have never had this problem before.
>>> >
>>> > Dave K4JRB
>>> >
>>> >
>>> >
>>> > --
>>> > FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
>>> > Submissions:              towertalk@contesting.com
>>> > Administrative requests:  towertalk-REQUEST@contesting.com
>>> > Problems:                 owner-towertalk@contesting.com
>>> > Search:                   http://www.contesting.com/km9p/search.htm
>>> >
>>
>>------------------------------
>>
To: <towertalk@contesting.com>
>>Date: Sun, 13 Jun 1999 11:19:02 -0400
>>From: jackson@cyberzane.net
>>Subject: [TowerTalk] Hard Line
>>
>>I am looking for about 180-200 ft of
>>Andrews 1/2 LDF hard line. Would like new.
>>Everett Jackson 1-740-452-7971 WZ8P
>>
>>------------------------------
>>
To: <towertalk@contesting.com>
>>Date: Sun, 13 Jun 1999 09:13:14 -0700
>>From: "Rod Brink" <rodbrink@montereybay.com>
>>Subject: [TowerTalk] ZL-Special
>>
>>Hi, does anyone know the historical origin of the ZL-Special antenna?
>>I have made one out of 300 ohm TV twin-lead and with the matching network
I
>>came up with, its SWR is 1:1 across the 17 meter band.  Am wondering if
this
>>adaptation has ever been done before and would love to read anything I can
>>get my hands on about this antenna.
>>
>>73, Rod
>>KE6RSF
>>
>>------------------------------
>>
To: <towertalk@contesting.com>
>>Date: Sun, 13 Jun 1999 11:00:30 -0700
>>From: "Rod Brink" <rodbrink@montereybay.com>
>>Subject: [TowerTalk] ZL-Special
>>
>>To Brian Harris who asked about my ZL-Special:
>>
>>Unfortunately I've recently moved and a lot of my stuff is in storage,
>>including my notes on that antenna.  However, I'll tell you what I
remember.
>>The two radiating elements were parallel, half-wave folded dipoles, each
>>about 25' 8" long, constructed of 300 ohm TV twinlead.  The phasing line
>>that interconnected them at their midpoints was 6' 8" long, also twinlead,
>>and was given a half-twist.  This put the two dipoles about 125 deg out of
>>phase from each other and gave the antenna its directionality and
>>front-to-back (which was about 18-20db.  My modeling software says that by
>>playing around a little with the length of the phasing line, its possibly
to
>>achieve theoretically infinite front-to-back).
>>The feedpoint impedance came out to be 35 +j30, as I remember.
>>I wound a toroidal 75-to-50 ohm transformer and connected it in parallel
>>with a 300 pf mica cap at the feedpoint to transform the 35 ohms to 50
ohms,
>>and to cancel out the inductive reactance.
>>
>>Physically, I suspended the antenna between aluminum conduit pipes 7' long
>>at the ends in order to maintain the spacing.  Matching network was built
>>into small plastic boxes I got at Radio Shack, and partly filled with
epoxy
>>for water-proofing.  I hung it horizontally, like a Yagi, at about 50'.  I
>>used RG-58 to hang down to the ground to minimize sag, then switched to
>>RG-8.
>>
>>Although  it wasn't the classiest looking thing in the world, it was a
>>KILLER antenna.
>>
>>73, Rod
>>
>>------------------------------
>>
To: <towertalk@contesting.com>
>>Date: Sun, 13 Jun 1999 14:10:49 -0400
>>From: "Guy Olinger, K2AV" <k2av@qsl.net>
>>Subject: Re: [TowerTalk] Force12 C-3 and Omni-VI+ Static Build-up
>>
>>- ----- Original Message -----
>>From: Tom Rauch <w8ji@contesting.com>
>>To: <W7TS@ibm.net>; <towertalk@contesting.com>; <K7LXC@aol.com>
>>Sent: Saturday, June 12, 1999 6:30 AM
>>Subject: Re: [TowerTalk] Force12 C-3 and Omni-VI+ Static Build-up
>>
>>
>>>
>>> >       Why not do the right thing by putting a lightning arrestor like
a
>>> > Polyphaser at the point where the coax enters the shack connected to a
>>> > couple of ground rods? It's not a lightning protection *system* but it
>>> > should protect your radio frontend from these static buildups.
>>> >
>>> >       This is probably the easiest option as well since it's at ground
>>> >       level
>>> > and you don't have to fool with the antenna.
>>>
>>> Polyphaser and other lightning arrestors do almost zero for
>>> protecting HF receivers. The problem is they have a breakdown
>>> voltage of about a kilovolt, and the receiver has a failure voltage of a
>>> few hundred volts or less.
>>
>>The grounding relays certainly do a lot, at the point where the remote
>>switchbox goes. Good first line of defense -- probably enough for a lot of
>>induced pulses. They will take care of the static from the antenna.  Close
>>lightning, however, is a different can of worms.
>>
>>If  one takes a direct hit on the tower, or very close, and the ground
>>saturates at the remote switchbox point, then the coax shield, and the
>>center conductor by induction, will arrive at the shack with a voltage to
>>settle.  If the shield is grounded at the house entrance point, that will
>>help drain the shield pulse. However, unless the center conductor is also
>>grounded at this point, it will carry a differential on to the rig.
>>
>>If a *DC-blocking* arrestor is used at the house entrance, in addition to
>>the ground of the shield, then the rest can be dealt with by a coax switch
>>at the rig that grounds the incoming and leaves the HF rig disconnected.
>>This, in a thimble summary, is what Polyphaser recommends. It is also a
very
>>good reason NOT to use a voltage-on-center-conductor type switch .... the
DC
>>blocking arrestor can't be used.
>>
>>The switch operating lines to the remote location will also have to
receive
>>arrestor treatment at the entrance point. These arrestors fire at much
lower
>>voltage, since you are protecting a 24v circuit, or less, and are a
greater
>>protection.
>>
>>*HOWEVER*, even if grounded at the house entrance, a rig-killing
>>differential can STILL be present, if the coax house entrance ground is
not
>>at or directly connected to the power service entrance ground.  As the
>>lightning pulse spreads out, (we are talking about a period measured in
>>microseconds) the ground closest to the strike is at a raised potential to
>>the ground farther away. THE GROUND ITSELF will use whatever pathways it
>>finds convenient in it's microseconds race to spread out and dissipate.
>>
>>One unfortunate path of ground potential equalization, since the stuff
under
>>the house is drier and often laced with less conductive construction
debris,
>>is this... Read and shudder...
>>
>>The path of ground equalization comes across the coax shield to the ground
>>at the house entrance. Blocked from direct propagation forward by basement
>>or less conductive material under the crawlspace, it goes up the shield of
>>the coax to the rig(s) and everything tied together by coax of any kind,
to
>>the green wire connection in the electrical system, and on over to the
power
>>service entrance ground. The ground equalization DOES go around the house,
>>but it takes LONGER to do so. In the time between the arrival of the outer
>>equalization around the house and back up the green wire from the power
>>ground, lies opportunity for all kinds of odd impedance and distance
related
>>destructive wierdness. The path through the house is high impedance
relative
>>to a robust ground bonding, and allows a way for the pulse to build up to
>>destructive potentials headed across.
>>
>>So, for this very short period of time, the *chassis* of your rig can be
at
>>a high potential above the inner circuitry, and a lot of other things in
the
>>house, as well, including above both neutral and high leads in the power
>>wiring. The rig then gets killed with a *backwards* zap, a very
short-lived,
>>but very chip-and-transistor-killing-capable backwards zap.
>>
>>In this circumstance, the common ground has become the enemy, because
there
>>was not a direct path from the coax entrance ground to the power service
>>entrance ground.  Depending on exactly how the power wiring physically
runs
>>inside the house, this could fry TV's, etc, even if the HF rig itself was
>>physically disconnected. All there needs to be is a path from the incoming
>>shield to something connected to a green wire in the power wiring.
>>
>>You may say, what about the station ground? Frequently the station ground
>>and the coax entrance ground are one and the same, aren't they? In this
case
>>you don't even need the shield of the coax to create the differential.
This
>>is NOT to say that you shouldn't have a station ground, just that it needs
a
>>good, robust bonding to the power service entrance ground, one that is the
>>most attractive route to a ground equalization pulse.
>>
>>The best condition, of course, is that the power entrance, telephone
>>entrance, coax entrance, and station ground are all one and the same.
>>
>>There has been at least one recent TowerTalk post of a rig-frying episode
I
>>would attribute to a ground equalization differential.
>>
>>Get the Polyphaser book, understand everything they explain, and do the
>>work. Using a grounding switch like the RCS-8V at the remote switch point
is
>>a good first step, but don't stop there.
>>
>>73, Guy.
>>
>>>
>>> The solution I use is relays, that automatically disconnect the
>>> center conductor. The RCS-8V does this, and the relay shorting
>>> bar goes to ground giving excellent protection.
>>>
>>
>>------------------------------
>>
To: <towertalk@contesting.com>
>>Date: Sun, 13 Jun 1999 14:53:52 EDT
>>From: KE4DGI@aol.com
>>Subject: [TowerTalk] Channel Master
>>
>>Hello all,
>>    I recently purchased a tower that the owner told me was a Channel
Master.
>>It is a three sided tower like you see advertised in AES catalogue. Does
any
>>one know where I can find information on this brand?
>>
>>Thanks
>>Tom Drake
>>ke4dgi@aol.com
>>
>>------------------------------
>>
To: <towertalk@contesting.com>
>>Date: Sun, 13 Jun 1999 17:56:26 -0500
>>From: Bob Perring <perring@texas.net>
>>Subject: Re: [TowerTalk] ZL-Special
>>
>>At 11:13 6/13/99 , Rod Brink wrote:
>>>Hi, does anyone know the historical origin of the ZL-Special antenna?
>>==============================>
>>Old CQ or QST back around 1960, or so.
>>Bamboo poles and twin lead.
>>Made one in 1964 and it worked great.
>>N5RP
>>
>>------------------------------
>>
To: <towertalk@contesting.com>
>>Date: Sun, 13 Jun 1999 18:00:50 -0500
>>From: Bob Perring <perring@texas.net>
>>Subject: Re: [TowerTalk] ZL-Special
>>
>>At 11:13 6/13/99 , Rod Brink wrote:
>>>Hi, does anyone know the historical origin of the ZL-Special antenna?
>>========================.
>>Was the original article called "A Scotsman's Delight" ?
>>I believe so.
>>A search of CQ or QST under that title might get you the original write
>>up.
>>N5RP
>>
>>------------------------------
>>
>>End of Tower Talk Digest V2 #217
>>********************************
>>
>>
>>--
>>FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
>>Submissions:              towertalk@contesting.com
>>Administrative requests:  towertalk-digest-REQUEST@contesting.com
>>Problems:                 owner-towertalk-digest@contesting.com
>
>
>
>--
>FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
>Submissions:              towertalk@contesting.com
>Administrative requests:  towertalk-REQUEST@contesting.com
>Problems:                 owner-towertalk@contesting.com
>Search:                   http://www.contesting.com/km9p/search.htm
>


--
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