Thanks to all who replied to my thread.
Here's an update. I finished my first vertical. It turns out I can put 48
feet vertical and do the rest as a sloping T-top. Total length of each wire is
66feet. I trimmed it to be resonant at 3.525 as instructed by Comtek manual.
I spaced the two wires comprising the vertical part of the antenna using some
old KLM spreaders which keep the two wires about six inches apart. Of course
the antenna does not produce a 50 ohm impedence. However, when measured with
an MFJ 259, the lowest SWR is at 3.525 and is 1.5. The 2:1 band width is
approximately 300kHz even with the "starting point" of 1.5 at resonance.
This is as far as I have gotten and right now am fighting rain to continue the
project. I believe the 6 inch spacing on the wires will accomplish my goal to
produce a 300kHz bandwidth using wires...at least it appears that way right now.
Bill K4XS/KH7XS
Message: 1
Date: Tue, 14 Nov 2017 14:36:12 -0500
From: "john@kk9a.com" <john@kk9a.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] 4 square advice
Message-ID: <f5ee6836470d1334f0cb0183431e7297.squirrel@www11.qth.com>
Content-Type: text/plain;charset=utf-8
AutoEZ appears to be a valuable tool. I am not designing anything new
lately but I'll still probably purchase it when I have some time to play.
To compare the 80m SWR bandwidth of different tubing sizes I used a simple
vertical model over average ground with no matching (resonant SWR~1.38).
2.00 tubing - 3.5MHz 1.87:1 3.8MHz 1.87:1
0.09 tubing - 3.5MHz 2.38:1 3.8MHz 2.38:1
-----Original Message-----
From: towertalk-request <towertalk-request@contesting.com>
To: towertalk <towertalk@contesting.com>
Sent: Wed, Nov 15, 2017 2:37 pm
Subject: TowerTalk Digest, Vol 179, Issue 25
Send TowerTalk mailing list submissions to
towertalk@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
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When replying, please edit your Subject line so it is more specific
than "Re: Contents of TowerTalk digest..."
Today's Topics:
1. Re: 4 square advice (john@kk9a.com)
2. Re: 4 square advice (Jeff)
3. Re: Help with Force 12 C3S 10-Meter Adjustments (John Bayne N4EEB)
4. OT. FS Tower & Coax Grounding-Sealing Kits (Gedas)
5. Re: OT. FS Tower & Coax Grounding-Sealing Kits (john@kk9a.com)
6. Ground wire between tower and ground stakes (Chris Hoelzle)
7. Re: OT. FS Tower & Coax Grounding-Sealing Kits (Gedas)
8. Re: OT. FS Tower & Coax Grounding-Sealing Kits (Steve Maki)
9. Re: Ground wire between tower and ground stakes (EZ Rhino)
10. Re: Ground wire between tower and ground stakes (Patrick Greenlee)
11. Re: Ground wire between tower and ground stakes (Dick's)
----------------------------------------------------------------------
Message: 1
Date: Tue, 14 Nov 2017 14:36:12 -0500
From: "john@kk9a.com" <john@kk9a.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] 4 square advice
Message-ID: <f5ee6836470d1334f0cb0183431e7297.squirrel@www11.qth.com>
Content-Type: text/plain;charset=utf-8
AutoEZ appears to be a valuable tool. I am not designing anything new
lately but I'll still probably purchase it when I have some time to play.
To compare the 80m SWR bandwidth of different tubing sizes I used a simple
vertical model over average ground with no matching (resonant SWR~1.38).
2.00 tubing - 3.5MHz 1.87:1 3.8MHz 1.87:1
0.09 tubing - 3.5MHz 2.38:1 3.8MHz 2.38:1
John KK9A
To: towertalk@contesting.com
Subject: Re: [TowerTalk] 4 square advice
From: Jim Brown <jim@audiosystemsgroup.com>
Reply-to: jim@audiosystemsgroup.com
Date: Sun, 12 Nov 2017 10:25:13 -0800
On 11/12/2017 7:35 AM, john@kk9a.com wrote:
You don't need AutoEZ to see the effect, EZNEC will work.
Right. But AutoEZ allows us to do a LOT more calculations a LOT faster.
If you own Excel, AutoEZ is well worth the $75 cost.
I just ran a model
of a single vertical using 2.00" tubing and one with .090" tubing. The
bandwidth difference was more different than I would have guessed.
What was that difference, John?
73, Jim K9YC
------------------------------
Message: 2
Date: Tue, 14 Nov 2017 13:48:49 -0600
From: "Jeff" <keepwalking188@ac0c.com>
To: <john@kk9a.com>, <towertalk@contesting.com>
Subject: Re: [TowerTalk] 4 square advice
Message-ID: <BECBCF92E2884E22B156E79696EFE16A@w520>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
But you are talking about a 4-square and not a vertical. So this experiment
shows that a vertical with a fatter element is more broadbanded and that
certainly implies the same with a 4-square, but it does not in a practical
sense convey the specific benefit of using a wider element in the common
case of a 4-square with a conventional hybrid combiner. What I wanted to
know was the return on my investment hassle to use the dual wires. AutoEZ
provides me that answer which is why I point it out.
The author has cooked up a hybrid as part of the 4-sq model and that means
you I can look specifically at the dump power % coming off the combiner over
my bandwidth of interest as I vary the element sizes. My plan is to build
up the array with a single wire for start and measure the dump power and
then move to the 2 wire to test the model prediction.
Good luck
73/jeff/ac0c
www.ac0c.com
alpha-charlie-zero-charlie
-----Original Message-----
From: john@kk9a.com
Sent: Tuesday, November 14, 2017 1:36 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] 4 square advice
AutoEZ appears to be a valuable tool. I am not designing anything new
lately but I'll still probably purchase it when I have some time to play.
To compare the 80m SWR bandwidth of different tubing sizes I used a simple
vertical model over average ground with no matching (resonant SWR~1.38).
2.00 tubing - 3.5MHz 1.87:1 3.8MHz 1.87:1
0.09 tubing - 3.5MHz 2.38:1 3.8MHz 2.38:1
John KK9A
To: towertalk@contesting.com
Subject: Re: [TowerTalk] 4 square advice
From: Jim Brown <jim@audiosystemsgroup.com>
Reply-to: jim@audiosystemsgroup.com
Date: Sun, 12 Nov 2017 10:25:13 -0800
On 11/12/2017 7:35 AM, john@kk9a.com wrote:
You don't need AutoEZ to see the effect, EZNEC will work.
Right. But AutoEZ allows us to do a LOT more calculations a LOT faster.
If you own Excel, AutoEZ is well worth the $75 cost.
I just ran a model
of a single vertical using 2.00" tubing and one with .090" tubing. The
bandwidth difference was more different than I would have guessed.
What was that difference, John?
73, Jim K9YC
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
------------------------------
Message: 3
Date: Tue, 14 Nov 2017 15:13:54 -0500 (GMT-05:00)
From: John Bayne N4EEB <john.bayne@earthlink.net>
To: Tower Talk <towertalk@contesting.com>
Subject: Re: [TowerTalk] Help with Force 12 C3S 10-Meter Adjustments
Message-ID:
<856509029.11972.1510690435141@wamui-kristoff.atl.sa.earthlink.net>
Content-Type: text/plain; charset=UTF-8
First, thank you so much for the extreme response from hams both on and off the
mailing list. I'm truly grateful for everyone's input. I have learned so much
already.
1. Two element yagi antennas of this design are a strange breed. They can be
counter intuitive, because the driver on a particular band is designed with
impedance in mind first. It is possible even, (not in this antenna), for a
driver to be longer than a reflector.
2. Computer plots of the numbers I supplied by hams with analysis programs
correctly suggested that adjusting the length of the reflector would not
improve the performance of the antenna.
3. As for the length of extension of the driver tips for 10m, the arguments
support from 1.5 to 4 inches or so. However, a surprise phone call from a
respected genius today gave me a starting number that is within that number
range.
So! I'm going to adjust the 10m driver tips outward, and when it's all said
and done I'm gonna come back here with the numbers and tell you how awesome
I've made this antenna with all of your help!
Thank you. See ya soon.
73 John N4EEB
------------------------------
Message: 4
Date: Tue, 14 Nov 2017 15:56:27 -0500
From: Gedas <w8bya@mchsi.com>
To: towertalk@contesting.com, moon-net@mailman.pe1itr.com,
TestEquipTrader@yahoogroups.com
Subject: [TowerTalk] OT. FS Tower & Coax Grounding-Sealing Kits
Message-ID: <3e792596-bce6-4e74-2c8a-fc4c11f40989@mchsi.com>
Content-Type: text/plain; charset=utf-8; format=flowed
I found 9 NOS, Andrew LDF12 "Sureground" grounding kits down in the
dungeon that I was saving but will never use. Each OEM bag contains a
roll of Scotch 3M, Type 700 Commercial/Industrial, 7 mil tape, approx
21' x 2" and rated for up to 190F service. This is the best tape I have
ever used for sealing coaxial connections.
Also included is a roll of Andrew Commercial/Industrial "hand-moldable"
sealing tape. Approx 22" x 2-1/2". Slightly over 1/8" thick and very
soft and gooey. Meant to be hand molded/formed over sensitive
connections before the final layers of the outer tape is applied.
Also included is a ~38" long, #6 insulated, stranded copper cable for
tower grounding. One end has an attached copper "cradle" or "strap" that
can open & close making it easy to wrap around the tower leg. The copper
strap is about 6"-7" long (if you were to open itup & flatten it out and
about 1-3/4" wide. Copper is nice and very shiny. The other end of the
#6 cable has a heavy-duty, crimped on (with double holes), terminal lug
with ~3/8" holes. Also in the kit are a pair of 1" long x 3/8" dia. SS
bolts that are designed to go through the 2 terminal lug holes of the
crimped on terminal. The 2 bolts come with 4 lock washers, 2 nuts and
are all S.S.Also is some anti-seize compound in a separate sealed bag.
As these are NOS some of them may have some of the black "hand-moldable"
sealant on some of the items in the bag because Andrew does not put that
stuff in a separate baggy. Also one bag was opened up by me so I could
make measurements of the items listed above. All bags have an Andrew
instructionsheet. Asking $20 per kit. A USPS medium or large flat rate
box would work well here for 4-6 of them unless someone wanted to
purchase all of them, in which case I would need to put them all in a
slightly larger box and ship via FedEx, USPS, etc. PayPal works aok for me.
Gedas, W8BYA
Gallery at http://w8bya.com
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
------------------------------
Message: 5
Date: Tue, 14 Nov 2017 18:19:14 -0500
From: <john@kk9a.com>
To: <towertalk@contesting.com>
Subject: Re: [TowerTalk] OT. FS Tower & Coax Grounding-Sealing Kits
Message-ID: <00aa01d35d9e$ff6ce960$fe46bc20$@com>
Content-Type: text/plain; charset="us-ascii"
LDF12 is HUGE coaxial cable!
John KK9A
To: towertalk@contesting.com, moon-net@mailman.pe1itr.com,
TestEquipTrader@yahoogroups.com
Subject: [TowerTalk] OT. FS Tower & Coax Grounding-Sealing Kits
From: Gedas <w8bya@mchsi.com>
Date: Tue, 14 Nov 2017 15:56:27 -0500
I found 9 NOS, Andrew LDF12 "Sureground" grounding kits down in the dungeon
that I was saving but will never use. Each OEM bag contains a roll of Scotch
3M, Type 700 Commercial/Industrial, 7 mil tape, approx 21' x 2" and rated
for up to 190F service. This is the best tape I have ever used for sealing
coaxial connections.
Also included is a roll of Andrew Commercial/Industrial "hand-moldable"
sealing tape. Approx 22" x 2-1/2". Slightly over 1/8" thick and very soft
and gooey. Meant to be hand molded/formed over sensitive connections before
the final layers of the outer tape is applied.
Also included is a ~38" long, #6 insulated, stranded copper cable for tower
grounding. One end has an attached copper "cradle" or "strap" that can open
& close making it easy to wrap around the tower leg. The copper strap is
about 6"-7" long (if you were to open itup & flatten it out and about 1-3/4"
wide. Copper is nice and very shiny. The other end of the #6 cable has a
heavy-duty, crimped on (with double holes), terminal lug with ~3/8" holes.
Also in the kit are a pair of 1" long x 3/8" dia. SS bolts that are designed
to go through the 2 terminal lug holes of the crimped on terminal. The 2
bolts come with 4 lock washers, 2 nuts and are all S.S.Also is some
anti-seize compound in a separate sealed bag. As these are NOS some of them
may have some of the black "hand-moldable" sealant on some of the items in
the bag because Andrew does not put that stuff in a separate baggy. Also one
bag was opened up by me so I could make measurements of the items listed
above. All bags have an Andrew instructionsheet. Asking $20 per kit. A USPS
medium or large flat rate box would work well here for 4-6 of them unless
someone wanted to purchase all of them, in which case I would need to put
them all in a slightly larger box and ship via FedEx, USPS, etc. PayPal
works aok for me.
Gedas, W8BYA
------------------------------
Message: 6
Date: Tue, 14 Nov 2017 15:26:21 -0800
From: "Chris Hoelzle" <choelzle@cox.net>
To: <TowerTalk@contesting.com>
Subject: [TowerTalk] Ground wire between tower and ground stakes
Message-ID: <000901d35d9f$fb2c6410$f1852c30$@cox.net>
Content-Type: text/plain; charset="us-ascii"
Hello TT's
I am getting ready to order my ground wire. I have seen conflicting
information about the type of wire to go between the tower and the ground
rods.
I had been planning on going with Solid AWG 2, but then I saw some pictures
of folks using stranded.
Could I get a vote on which type of wire is commonly used for most amateur
tower applications
Thanks
W7MI
Chris Hoelzle
choelzle@cox.net
Bandon, OR
------------------------------
Message: 7
Date: Tue, 14 Nov 2017 19:03:34 -0500
From: Gedas <w8bya@mchsi.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] OT. FS Tower & Coax Grounding-Sealing Kits
Message-ID: <cc9856ff-443a-d31b-3b92-b679a07cfa18@mchsi.com>
Content-Type: text/plain; charset=utf-8; format=flowed
How else are you going to have a HUGE signal ? <g>. Luckily the copper
can be cut to wrap around any cable and secured with a couple hose
clamps etc.
Gedas, W8BYA
Gallery at http://w8bya.com
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 11/14/2017 6:19 PM, john@kk9a.com wrote:
> LDF12 is HUGE coaxial cable!
>
> John KK9A
>
>
>
> To: towertalk@contesting.com, moon-net@mailman.pe1itr.com,
> TestEquipTrader@yahoogroups.com
> Subject: [TowerTalk] OT. FS Tower & Coax Grounding-Sealing Kits
> From: Gedas <w8bya@mchsi.com>
> Date: Tue, 14 Nov 2017 15:56:27 -0500
>
> I found 9 NOS, Andrew LDF12 "Sureground" grounding kits down in the dungeon
> that I was saving but will never use. Each OEM bag contains a roll of Scotch
> 3M, Type 700 Commercial/Industrial, 7 mil tape, approx 21' x 2" and rated
> for up to 190F service. This is the best tape I have ever used for sealing
> coaxial connections.
>
> Also included is a roll of Andrew Commercial/Industrial "hand-moldable"
> sealing tape. Approx 22" x 2-1/2". Slightly over 1/8" thick and very soft
> and gooey. Meant to be hand molded/formed over sensitive connections before
> the final layers of the outer tape is applied.
>
> Also included is a ~38" long, #6 insulated, stranded copper cable for tower
> grounding. One end has an attached copper "cradle" or "strap" that can open
> & close making it easy to wrap around the tower leg. The copper strap is
> about 6"-7" long (if you were to open itup & flatten it out and about 1-3/4"
> wide. Copper is nice and very shiny. The other end of the #6 cable has a
> heavy-duty, crimped on (with double holes), terminal lug with ~3/8" holes.
> Also in the kit are a pair of 1" long x 3/8" dia. SS bolts that are designed
> to go through the 2 terminal lug holes of the crimped on terminal. The 2
> bolts come with 4 lock washers, 2 nuts and are all S.S.Also is some
> anti-seize compound in a separate sealed bag. As these are NOS some of them
> may have some of the black "hand-moldable" sealant on some of the items in
> the bag because Andrew does not put that stuff in a separate baggy. Also one
> bag was opened up by me so I could make measurements of the items listed
> above. All bags have an Andrew instructionsheet. Asking $20 per kit. A USPS
> medium or large flat rate box would work well here for 4-6 of them unless
> someone wanted to purchase all of them, in which case I would need to put
> them all in a slightly larger box and ship via FedEx, USPS, etc. PayPal
> works aok for me.
>
> Gedas, W8BYA
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
------------------------------
Message: 8
Date: Tue, 14 Nov 2017 19:03:16 -0500
From: Steve Maki <lists@oakcom.org>
To: towertalk <towertalk@contesting.com>
Subject: Re: [TowerTalk] OT. FS Tower & Coax Grounding-Sealing Kits
Message-ID: <406d175e-2b44-2722-51ac-f991cdaf126c@oakcom.org>
Content-Type: text/plain; charset=utf-8; format=flowed
2-1/4" Heliax. We installed a bunch of it on cell sites, but the
customers finally figured out that it was overkill. Bump the TX power up
a bit if you like, and install TMA's (tower mounted pre-amps) near the
antenna for Rx noise figure purposes, and save tower lease cost by
reducing feedline weight and windload.
Of course there exists much larger coax mostly found on high power FM
stations and VHF/low UHF TV stations. Higher channels will be waveguide.
-Steve K8LX
On 11/14/2017 18:19 PM, john@kk9a.com wrote:
> LDF12 is HUGE coaxial cable!
>
> John KK9A
> I found 9 NOS, Andrew LDF12 "Sureground" grounding kits down in the dungeon
> that I was saving but will never use. Each OEM bag contains a roll of Scotch
> 3M, Type 700 Commercial/Industrial, 7 mil tape, approx 21' x 2" and rated
> for up to 190F service. This is the best tape I have ever used for sealing
> coaxial connections.
------------------------------
Message: 9
Date: Tue, 14 Nov 2017 19:52:20 -0700
From: EZ Rhino <EZRhino@fastmovers.biz>
To: Towertalk Reflector <towertalk@contesting.com>
Subject: Re: [TowerTalk] Ground wire between tower and ground stakes
Message-ID: <8320B302-33CB-4EE1-BEAC-304B2F1EFE3D@fastmovers.biz>
Content-Type: text/plain; charset=us-ascii
I personally think solid wire is better, but when you're talking about #2
solid, stuff that big gets pretty difficult to work with. It's as big around
as my little finger and requires a lot of strength to manipulate! Stranded is
easier to bend. I've seen both used, and both work fine in Cadwelds if you
want a welded bond to your ground rod.
Chris
KF7P
On Nov 14, 2017, at 16:26 , Chris Hoelzle wrote:
Hello TT's
I am getting ready to order my ground wire. I have seen conflicting
information about the type of wire to go between the tower and the ground
rods.
I had been planning on going with Solid AWG 2, but then I saw some pictures
of folks using stranded.
Could I get a vote on which type of wire is commonly used for most amateur
tower applications
Thanks
W7MI
Chris Hoelzle
choelzle@cox.net
Bandon, OR
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
------------------------------
Message: 10
Date: Wed, 15 Nov 2017 07:27:11 -0600
From: Patrick Greenlee <patrick_g@windstream.net>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Ground wire between tower and ground stakes
Message-ID: <9b264e89-921c-3758-03f5-da8a56527ac3@windstream.net>
Content-Type: text/plain; charset=utf-8; format=flowed
Voting frequently does not select the best choice. (Ref, several
presidential elections)
Solid wire is clearly superior for corrosion resistance? (hence longer
life in adverse environment) but is not best if it has to flex. Flexing
is where stranded is king.
Patrick??????? NJ5G
On 11/14/2017 5:26 PM, Chris Hoelzle wrote:
> Hello TT's
>
>
>
> I am getting ready to order my ground wire. I have seen conflicting
> information about the type of wire to go between the tower and the ground
> rods.
>
>
>
> I had been planning on going with Solid AWG 2, but then I saw some pictures
> of folks using stranded.
>
>
>
> Could I get a vote on which type of wire is commonly used for most amateur
> tower applications
>
>
>
> Thanks
>
>
>
> W7MI
>
> Chris Hoelzle
> choelzle@cox.net
> Bandon, OR
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
------------------------------
Message: 11
Date: Wed, 15 Nov 2017 08:29:48 -0500
From: Dick's <rcblumen@centurylink.net>
To: Chris Hoelzle <choelzle@cox.net>
Cc: TowerTalk@contesting.com
Subject: Re: [TowerTalk] Ground wire between tower and ground stakes
Message-ID: <7A0CEDF6-55C1-4A76-A2C2-AB6ED9B64EE2@centurylink.net>
Content-Type: text/plain; charset=utf-8
Hello Chris:
As we write, I am presently connecting all my 10 ground rods with 2 awg
stranded Cu using Harger cad welds. I received a lot of input from people and
have looked at products that allow one to bolt wires to the tower base as well
as clamping systems.
I chose to go with using thin Cu sheeting 3? wide clamped onto each tower leg
and gently arced down to the ground rod at each tower leg. The reason I chose
to do that was because lighting doesn?t like to take 90 degree turns as would
happen if a wires or foil were attached at the bottom bolts.
K7FP sells all kinds of clamps and Cu sheeting to do that.
My plan, while ungainly (especially when I have to lower my tower horizontally
to derive the antenna array) will have the Cu foil attach to the ground rod
below the cad weld. I plan to surround the tower concrete with gravel so I can
access the copper foil clamps in the future to inspect the connection.
If you decide to go in this direction, make sure you put stainless shim stock
between the copper foil and the tower as well as anti corrosion paste before
clamping.
It sure won?t be pretty, but I?m a functional guy.
Dick, K0CAT
> ??-
>
>
>
> I am getting ready to order my ground wire. I have seen conflicting
> information about the type of wire to go between the tower and the ground
> rods.
>
>
>
> I had been planning on going with Solid AWG 2, but then I saw some pictures
> of folks using stranded.
>
>
>
> Could I get a vote on which type of wire is commonly used for most amateur
> tower applications
>
>
>
> Thanks
>
>
>
> W7MI
>
> Chris Hoelzle
> choelzle@cox.net
> Bandon, OR
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
------------------------------
Subject: Digest Footer
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------------------------------
End of TowerTalk Digest, Vol 179, Issue 25
******************************************
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