Did they make a tribander with only six traps? Seems unlikely.
WL
-----Original Message-----
From: towertalk-request@contesting.com
Sent: Tuesday, December 09, 2014 9:11 PM
To: towertalk@contesting.com
Subject: TowerTalk Digest, Vol 144, Issue 15
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Today's Topics:
1. Re: Dipole gain? (Ken)
2. Re: Dipole gain? (Jim Lux)
3. Fwd: Dipole gain? (Hans Hammarquist via TowerTalk)
4. Fwd: Dipole gain? (Hans Hammarquist via TowerTalk)
5. Re: Fwd: Dipole gain? (Joe Subich, W4TV)
6. CDR Telex Hi Gain Control Box (Wayne Kline)
7. Re: Conduit installed in foundation slab (Gene Smar)
8. Trap Identification Hepl Please (Wilson)
9. Trap Identification (W1JCW)
----------------------------------------------------------------------
Message: 1
Date: Tue, 9 Dec 2014 16:46:38 -0500
From: Ken <wa8jxm@gmail.com>
To: Matt <maflukey@gmail.com>
Cc: Towertalk <towertalk@contesting.com>
Subject: Re: [TowerTalk] Dipole gain?
Message-ID: <92E6C884-D33C-4129-BAD4-79C9A5E4A1A1@gmail.com>
Content-Type: text/plain; charset=utf-8
And since very few of us operate in free space, dipole gain varies all over
the scale dependent on hight above ground and the angle you want to measure
the ?gain? at. I have recently seen where a dipole at the proper height
has up to 8 dbi gain (at the right height and at a desired angle).
In actuality, ?gain? in a non rotatable antenna is a myth. OVERALL, an
antenna has no gain over an isotropic radiator, it just subtracts strength
is one direction and focuses it elsewhere. That?s good if ?elsewhere? is
the direction you want to communicate, and not good if you want to
communicate in some other direction.
Ken WA8JXM
On Dec 8, 2014, at 10:14 PM, Matt <maflukey@gmail.com> wrote:
A dipole in free space can be mathematically shown to have a theoretical
far-field gain of 2.14 dB over an isotropic radiator.
------------------------------
Message: 2
Date: Tue, 09 Dec 2014 13:53:48 -0800
From: Jim Lux <jimlux@earthlink.net>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Dipole gain?
Message-ID: <54876F6C.6080905@earthlink.net>
Content-Type: text/plain; charset=UTF-8; format=flowed
On 12/9/14, 1:46 PM, Ken wrote:
And since very few of us operate in free space, dipole gain varies all
over the scale dependent on hight above ground and the angle you want to
measure the ?gain? at. I have recently seen where a dipole at the
proper height has up to 8 dbi gain (at the right height and at a desired
angle).
In actuality, ?gain? in a non rotatable antenna is a myth. OVERALL, an
antenna has no gain over an isotropic radiator, it just subtracts strength
is one direction and focuses it elsewhere. That?s good if ?elsewhere? is
the direction you want to communicate, and not good if you want to
communicate in some other direction.
gain can be negative. It's useful to talk about gain vs directivity.
The latter is assuming no loss.
------------------------------
Message: 3
Date: Tue, 9 Dec 2014 17:43:05 -0500
From: Hans Hammarquist via TowerTalk <towertalk@contesting.com>
To: towertalk@contesting.com
Subject: [TowerTalk] Fwd: Dipole gain?
Message-ID: <8D1E218A1C7D533-D24-27929@webmail-vm079.sysops.aol.com>
Content-Type: text/plain; charset="utf-8"
Hi Jim,
The next question then is; Do two horizontal, crossed dipoles, feed 90? out
of phase have an even power distribution across the hemisphere, horizontal
across the horizon and circular above and below or is there a direction with
a higher power density?
-----Original Message-----
From: Jim Lux <jimlux@earthlink.net>
To: Hans Hammarquist <hanslg@aol.com>
Sent: Mon, Dec 8, 2014 9:58 pm
Subject: Re: [TowerTalk] Dipole gain?
On 12/8/14, 6:45 PM, Hans Hammarquist via TowerTalk wrote:
That way you should
subtract 3 dB to get a comparison between an antenna gain give over
the isotropic. I was also told that two crossed dipoles were as close
to an isotropic radiator you could get.
Not really. two crossed dipoles fed in phase is the same as a dipole at
45 degrees. two crossed dipoles fed 90 degrees out of phase is
circularly polarized in the direction normal to the plane containing the
dipoles. Other arrangements of dipoles (e.g. a Lindenblad or a
turnstile) may have better circularity in some directions.
An antenna that is isotropic and has the same polarization in all
directions cannot exist (there's the interestingly named "hairy ball
theorem" about this).
------------------------------
Message: 4
Date: Tue, 9 Dec 2014 17:45:34 -0500
From: Hans Hammarquist via TowerTalk <towertalk@contesting.com>
To: towertalk@contesting.com
Subject: [TowerTalk] Fwd: Dipole gain?
Message-ID: <8D1E218FA081466-D24-27963@webmail-vm079.sysops.aol.com>
Content-Type: text/plain; charset="utf-8"
Hi Jim,
The next question then is; Do two horizontal, crossed dipoles, feed 90? out
of phase have an even power distribution across the hemisphere, horizontal
across the horizon and circular above and below or is there a direction with
a higher power density?
Hans - N2JFS
-----Original Message-----
From: Jim Lux <jimlux@earthlink.net>
To: Hans Hammarquist <hanslg@aol.com>
Sent: Mon, Dec 8, 2014 9:58 pm
Subject: Re: [TowerTalk] Dipole gain?
On 12/8/14, 6:45 PM, Hans Hammarquist via TowerTalk wrote:
That way you should
subtract 3 dB to get a comparison between an antenna gain give over
the isotropic. I was also told that two crossed dipoles were as close
to an isotropic radiator you could get.
Not really. two crossed dipoles fed in phase is the same as a dipole at
45 degrees. two crossed dipoles fed 90 degrees out of phase is
circularly polarized in the direction normal to the plane containing the
dipoles. Other arrangements of dipoles (e.g. a Lindenblad or a
turnstile) may have better circularity in some directions.
------------------------------
Message: 5
Date: Tue, 09 Dec 2014 17:59:24 -0500
From: "Joe Subich, W4TV" <lists@subich.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Fwd: Dipole gain?
Message-ID: <54877ECC.6030605@subich.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Any horizontal antenna will have a direction (angle above
horizontal) with higher power density due to the combination
of direct rays and rays reflected from the ground.
The turnstile, if properly fed, will have uniform angular
radiation in the horizontal plane. Vertical "take off" angle
will depend on height above ground and the "circular" radiation
directly up will depend again on height above ground and the
ground constants.
73,
... Joe, W4TV
On 2014-12-09 5:45 PM, Hans Hammarquist via TowerTalk wrote:
Hi Jim,
The next question then is; Do two horizontal, crossed dipoles, feed 90?
out of phase have an even power distribution across the hemisphere,
horizontal across the horizon and circular above and below or is there a
direction with a higher power density?
Hans - N2JFS
-----Original Message-----
From: Jim Lux <jimlux@earthlink.net>
To: Hans Hammarquist <hanslg@aol.com>
Sent: Mon, Dec 8, 2014 9:58 pm
Subject: Re: [TowerTalk] Dipole gain?
On 12/8/14, 6:45 PM, Hans Hammarquist via TowerTalk wrote:
That way you should
subtract 3 dB to get a comparison between an antenna gain give over
the isotropic. I was also told that two crossed dipoles were as close
to an isotropic radiator you could get.
Not really. two crossed dipoles fed in phase is the same as a dipole at
45 degrees. two crossed dipoles fed 90 degrees out of phase is
circularly polarized in the direction normal to the plane containing the
dipoles. Other arrangements of dipoles (e.g. a Lindenblad or a
turnstile) may have better circularity in some directions.
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------------------------------
Message: 6
Date: Tue, 9 Dec 2014 18:26:51 -0500
From: Wayne Kline <w3ea@hotmail.com>
To: "towertalk@contesting.com" <towertalk@contesting.com>
Subject: [TowerTalk] CDR Telex Hi Gain Control Box
Message-ID: <BAY177-W374382DD4746B40B84A9CE8F650@phx.gbl>
Content-Type: text/plain; charset="iso-8859-1"
The WX has be catching up on some repair work I need the small
transformer 110V Pri - 30 V secd. meter lamp transformer.
I know all boxes even the old Ham M used them ...
any in a the junk pile ? this is the first on I ever ran into in many many
box repairs
Wayne W3EA ..
------------------------------
Message: 7
Date: Tue, 09 Dec 2014 18:37:35 -0500
From: "Gene Smar" <ersmar@verizon.net>
To: "'Marsh Stewart'" <marsh@ka5m.net>, <towertalk@contesting.com>
Subject: Re: [TowerTalk] Conduit installed in foundation slab
Message-ID: <002801d01409$1d05b980$57112c80$@verizon.net>
Content-Type: text/plain; charset=US-ASCII
Blair:
Instead of the weatherhead (expensive), you can use two pieces of PVC
elbow joined together to make a 180 degree turn at the top of the conduit.
You'll need a straight joint to connect the two together. Pull the coax
through and downward, then plug up the hole with fiberglass (fibreglass in
VE-land) insulation.
73 de
Gene Smar AD3F
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of Marsh
Stewart
Sent: Tuesday, December 09, 2014 7:50 AM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Conduit installed in foundation slab
The electrical device you are referring to is called a "weatherhead".
Marsh, KA5M
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of Blair
Sent: Tuesday, December 09, 2014 4:26 AM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Conduit installed in foundation slab
Thank to everyone who replied to my query. You have asuaged my fears and
will proceed with embedding my feedline conduit in the tower foundation. I
will likely cap the schedule 80 conduit with a termination similar to that
which is used for overhead electrical utility lines feeding a meter base. I
can't recall the actual name for this cap at the moment, but you get the
idea.
Regards, Blair.
VE3ZBM
On 12/08/14, Blair (VE3ZBM) wrote:
Good afternoon, All.
I have not found a satisfactory answer to whether or not a 2 or 3" schedule
40 PVC conduit, installed ~3' below grade and into a 5' x 5' x 4' deep
steel-reinforced free standing tower foundation will derate or harm the
slab's overall integrity. I am preparing for my new tower (to be installed
next spring) and would like to bring the cable feeds up inside the tower
base thereby eliminating tripping hazards and other aesthetic concerns.
Thanks in advance,
Blair VE3ZBM
Sent from my iPhone
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------------------------------
Message: 8
Date: Tue, 9 Dec 2014 20:18:01 -0500
From: "Wilson" <infomet@embarqmail.com>
To: "towertalk" <towertalk@contesting.com>
Subject: [TowerTalk] Trap Identification Hepl Please
Message-ID: <BF5262BAAEC84C149AB0A27ADDB4BB68@WilsonPC>
Content-Type: text/plain; charset="UTF-8"
I have five nice traps, who knows where they came from or what happened to
the sixth.
They are labeled Director, Reflector, and Radiator.
I never saw anything called radiator, so it?s likely an ID help.
You can see them in my Dropbox:
https://www.dropbox.com/s/1u12u0f9fa3690b/Traps.JPG?dl=0
Can anyone tell me what these were for?
Was it a two band beam, since there may have been only six?
Wilson
W4BOH
------------------------------
Message: 9
Date: Tue, 9 Dec 2014 20:11:31 -0600
From: W1JCW <w1jcw@hotmail.com>
To: "'towertalk'" <towertalk@contesting.com>
Subject: [TowerTalk] Trap Identification
Message-ID: <SNT150-DS381440B55699AC1D435D8F7620@phx.gbl>
Content-Type: text/plain; charset="utf-8"
Those are Mosley traps.
The radiator is aka the driven element.
Most likely a tri-band beam 10/15/20m.
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
Wilson
Sent: Tuesday, December 09, 2014 7:18 PM
To: towertalk
Subject: [TowerTalk] Trap Identification Hepl Please
I have five nice traps, who knows where they came from or what happened to
the sixth.
They are labeled Director, Reflector, and Radiator.
I never saw anything called radiator, so it?s likely an ID help.
You can see them in my Dropbox:
https://www.dropbox.com/s/1u12u0f9fa3690b/Traps.JPG?dl=0
Can anyone tell me what these were for?
Was it a two band beam, since there may have been only six?
Wilson
W4BOH
------------------------------
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------------------------------
End of TowerTalk Digest, Vol 144, Issue 15
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