[TowerTalk] TowerTalk Digest, Vol 144, Issue 15

Tue Dec 9 21:36:37 EST 2014

Did they make a tribander with only six traps?  Seems unlikely.
WL

-----Original Message----- 
From: towertalk-request at contesting.com
Sent: Tuesday, December 09, 2014 9:11 PM
To: towertalk at contesting.com
Subject: TowerTalk Digest, Vol 144, Issue 15

Send TowerTalk mailing list submissions to
towertalk at contesting.com

To subscribe or unsubscribe via the World Wide Web, visit
http://lists.contesting.com/mailman/listinfo/towertalk
or, via email, send a message with subject or body 'help' to
towertalk-request at contesting.com

You can reach the person managing the list at
towertalk-owner at contesting.com

When replying, please edit your Subject line so it is more specific
than "Re: Contents of TowerTalk digest..."

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 at gmail.com>
To: Matt <maflukey at gmail.com>
Cc: Towertalk <towertalk at contesting.com>
Subject: Re: [TowerTalk] Dipole gain?
Message-ID: <92E6C884-D33C-4129-BAD4-79C9A5E4A1A1 at 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 at 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 at earthlink.net>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Dipole gain?
Message-ID: <54876F6C.6080905 at 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 at contesting.com>
To: towertalk at contesting.com
Subject: [TowerTalk] Fwd:  Dipole gain?
Message-ID: <8D1E218A1C7D533-D24-27929 at 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 at earthlink.net>
To: Hans Hammarquist <hanslg at 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 at contesting.com>
To: towertalk at contesting.com
Subject: [TowerTalk] Fwd:  Dipole gain?
Message-ID: <8D1E218FA081466-D24-27963 at 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 at earthlink.net>
To: Hans Hammarquist <hanslg at 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 at subich.com>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Fwd:  Dipole gain?
Message-ID: <54877ECC.6030605 at 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 at earthlink.net>
> To: Hans Hammarquist <hanslg at 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.
>
>
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>

------------------------------

Message: 6
Date: Tue, 9 Dec 2014 18:26:51 -0500
From: Wayne Kline <w3ea at hotmail.com>
To: "towertalk at contesting.com" <towertalk at contesting.com>
Subject: [TowerTalk] CDR Telex Hi Gain  Control Box
Message-ID: <BAY177-W374382DD4746B40B84A9CE8F650 at 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 at verizon.net>
To: "'Marsh Stewart'" <marsh at ka5m.net>, <towertalk at 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 at contesting.com] On Behalf Of Marsh
Stewart
Sent: Tuesday, December 09, 2014 7:50 AM
To: towertalk at 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 at contesting.com] On Behalf Of Blair
Sent: Tuesday, December 09, 2014 4:26 AM
To: towertalk at 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
_______________________________________________

_______________________________________________
TowerTalk mailing list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________

_______________________________________________
TowerTalk mailing list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

_______________________________________________

_______________________________________________
TowerTalk mailing list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

------------------------------

Message: 8
Date: Tue, 9 Dec 2014 20:18:01 -0500
From: "Wilson" <infomet at embarqmail.com>
To: "towertalk" <towertalk at contesting.com>
Subject: [TowerTalk] Trap Identification Hepl Please
Message-ID: <BF5262BAAEC84C149AB0A27ADDB4BB68 at 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 at hotmail.com>
To: "'towertalk'" <towertalk at contesting.com>
Subject: [TowerTalk] Trap Identification
Message-ID: <SNT150-DS381440B55699AC1D435D8F7620 at 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 at 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

------------------------------

Subject: Digest Footer

_______________________________________________
TowerTalk mailing list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

------------------------------

End of TowerTalk Digest, Vol 144, Issue 15
****************************************** 