[TowerTalk] Re: TowerTalk Digest, Vol 24, Issue 36

Sat Dec 11 13:39:57 EST 2004

I believe the % of tower length is 80 % with rohn tower
----- Original Message ----- 
From: <towertalk-request at contesting.com>
To: <towertalk at contesting.com>
Sent: Saturday, December 11, 2004 11:00 AM
Subject: TowerTalk Digest, Vol 24, Issue 36


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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 at adelphia.net>
> Subject: [TowerTalk] Guy anchor distance from tower base?
> To: <TowerTalk at contesting.com>
> Message-ID: <001501c4df7a$fe97ec70$6401a8c0 at 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 at arrl.net>
> Subject: RE: [TowerTalk] Guy anchor distance from tower base?
> To: "reflector -tower" <towertalk at contesting.com>
> Message-ID: <000401c4df7d$0ec7d5e0$0800a8c0 at 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 at arrl.net
> web: http://www.k1ttt.net
> AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
>
>
>> -----Original Message-----
>> From: towertalk-bounces at contesting.com [mailto:towertalk-
>> bounces at contesting.com] On Behalf Of SJ W3TX
>> Sent: Saturday, December 11, 2004 12:15
>> To: TowerTalk at 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 at 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 at verizon.net>
> Subject: RE: [TowerTalk] ICE 419A Combination Bandpass Filter 10M
> Section Blown
> To: "'David Hachadorian'" <K6LL at adelphia.net>, "'Towertalk Reflector'"
> <towertalk at contesting.com>
> Message-ID: <000801c4df03$c9b56220$6401a8c0 at 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 at contesting.com
> [mailto:towertalk-bounces at 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 at earthlink.net>
> To: "TowerTalk" <towertalk at 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 at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
>
>
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>
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>
> End of TowerTalk Digest, Vol 24, Issue 36
> *****************************************
>
>