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Today's Topics:
1. Guy anchor distance from tower base? (SJ W3TX)
2. RE: Guy anchor distance from tower base? (David Robbins K1TTT)
3. RE: ICE 419A Combination Bandpass Filter 10M Section Blown
(Tony Kazmakites)
----------------------------------------------------------------------
Message: 1
Date: Sat, 11 Dec 2004 07:14:42 -0500
From: "SJ W3TX" <superberthaguy@adelphia.net>
Subject: [TowerTalk] Guy anchor distance from tower base?
To: <TowerTalk@contesting.com>
Message-ID: <001501c4df7a$fe97ec70$6401a8c0@PC988720711140>
Content-Type: text/plain; charset="iso-8859-1"
I read the TIA-222 document, but it doesn't specify the recommended
distance
between the tower base and guy anchors (as a percent of tower height). I
may end up using 4 guy wire directions to allow me to place the tower base
closer to my setback (so the towers can be further apart).
What is the standard % for:
3 guy wire directions (guys spaced 120 degrees)?
4 guy wire directions (guys spaced 90 degrees)?
------------------------------
Message: 2
Date: Sat, 11 Dec 2004 12:29:27 -0000
From: "David Robbins K1TTT" <k1ttt@arrl.net>
Subject: RE: [TowerTalk] Guy anchor distance from tower base?
To: "reflector -tower" <towertalk@contesting.com>
Message-ID: <000401c4df7d$0ec7d5e0$0800a8c0@k1tttibm>
Content-Type: text/plain; charset="us-ascii"
Tia-222 can't calculate things like that because those types of
calculations
are up to the manufacturer and engineer designing the system.
Manufacturers
like rohn do sets of generic designs for 'standard' installations that
assume flat land, some max wind speed, and specify max wind and weight
loading... but those designs are only for specific tower configurations
and
can't cover all circumstances either. To get a safe design, especially
when
you are trying to do something odd like guying a triangular tower to 4
anchors, you must get a qualified engineer to design and approve it.
That said and noting that I am not a qualified engineer for this type of
stuff... just by geometric considerations you can put a tower closer to
something with 3 guy points than 4, assuming the location of the guy
points
are on the setback line and are the same distance from the base of the
tower. I would not expect the distance out from the base of the tower to
change much for 4 guy points vs 3, it is the distance out that determines
the angle to the tower and the side force exerted... and it is the side
force that keeps the tower upright. Move the buy points in and they pull
down more than out which does not help keep the tower straight up.
David Robbins K1TTT
e-mail: mailto:k1ttt@arrl.net
web: http://www.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
-----Original Message-----
From: towertalk-bounces@contesting.com [mailto:towertalk-
bounces@contesting.com] On Behalf Of SJ W3TX
Sent: Saturday, December 11, 2004 12:15
To: TowerTalk@contesting.com
Subject: [TowerTalk] Guy anchor distance from tower base?
I read the TIA-222 document, but it doesn't specify the recommended
distance
between the tower base and guy anchors (as a percent of tower height). I
may end up using 4 guy wire directions to allow me to place the tower
base
closer to my setback (so the towers can be further apart).
What is the standard % for:
3 guy wire directions (guys spaced 120 degrees)?
4 guy wire directions (guys spaced 90 degrees)?
_______________________________________________
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@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
------------------------------
Message: 3
Date: Fri, 10 Dec 2004 17:01:21 -0500
From: "Tony Kazmakites" <tony.kazmakites@verizon.net>
Subject: RE: [TowerTalk] ICE 419A Combination Bandpass Filter 10M
Section Blown
To: "'David Hachadorian'" <K6LL@adelphia.net>, "'Towertalk Reflector'"
<towertalk@contesting.com>
Message-ID: <000801c4df03$c9b56220$6401a8c0@MT001825LT>
Content-Type: text/plain; charset="iso-8859-1"
I had a set of ICE bandpass filters that never saw more than 100w - used
them on my Icom 751A to drive an amp. After I had used them for a few
years
I checked for insertion loss and passband. Some had changed. When I opened
up the ones that had changed I could see some caps that were blackened and
they had a burnt smell. That's when I bought a set of W3NQN filters.
73,
N2TK, Tony
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com]On Behalf Of David Hachadorian
Sent: Friday, December 10, 2004 4:20 PM
To: Towertalk Reflector
Subject: Re: [TowerTalk] ICE 419A Combination Bandpass Filter 10M Section
Blown
----- Original Message -----
From: "Keith Dutson" <kjdutson@earthlink.net>
To: "TowerTalk" <towertalk@contesting.com>
Sent: Friday, December 10, 2004 12:39 PM
Subject: [TowerTalk] ICE 419A Combination Bandpass
Filter 10M Section Blown
Subject says it all. VSWR went to 5 at some point
during operation of
VP8WWW. The filter box was set to 10 meters and
connected to a trapped
vertical and Kenwood 480HX. Transceiver was set to
200 watts CW on 10
meters. We were using two boxes and switched them.
About an hour later the
second box did the same thing.
I read the manual. It states the unit is rated at
200 watts. I am guessing
that is for SSB rather than CW. Anyone else
experience this problem?
Each filter section apparently consists of a simple
coil and two caps in T
configuration. This is only an observation as I do
not have a schematic. I
would like to beef up the capacity and assume this
might be done with higher
voltage caps.
Keith NM5G
-------------------------------
A friend of mine has the ICE filters, and I have helped
him change bad 10 meter capacitors twice now. At least
one other person has publicly complained of the same
thing. The factory guys say they have never heard of
such a problem. They did supply the replacement caps
for free, but it took a few weeks to get them, and by
then we had already purchased the replacement caps from
Mouser. The cap that failed both times was in the leg
that runs to ground on the rig side, not the antenna
side. This leg is a parallel combinaton of two caps.
The cap did not blow completely, rather it just made a
significant change in value. If you separate them you
can use an impedance measuring device, such as an
antenna analyzer, to figure out which one has changed.
The capacitor values are all different for the various
bands, but a typical Mouser part number would be
5982-19-500V270 for the 270 pF. The Mouser catalog does
have some 1000V micas, but the selection of values is
quite limited. You could switch to a parallel/series
combination of four 500V caps, at least in this leg.
Another thing I don't like about the ICE Filters is
that the signal path goes through 12 normally-closed
relay contacts. In my friend's units, he experiences
occasional signal dropout on receive. As soon as he
sends one 50 watt "dit" through the filter, the film on
the relay contacts is penetrated, and the receive
signals reappear. The factory guys say they have never
heard of that one, either.
Just pull the cover off the filter, and you will see
how it is built. At least it is easy to work on. We've
had the covers off my friend's unit so much that now we
just have to whistle, and the screws unscrew
themselves. After you change the caps, just squeeze the
10 meter coil/bend cap leads for min swr. We keep a
rubber glove handy for this purpose, to avoid rf burns,
and to avoid affecting the swr. Make final adjustment
with the cover on as far as you can get it, and still
be able to reach in. We can change these caps in about
ten minutes now. It looks like a Wood brothers' pit
stop.
Dave Hachadorian, K6LL
Yuma, AZ
_______________________________________________
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@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
------------------------------
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
End of TowerTalk Digest, Vol 24, Issue 36
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