[TowerTalk] vertical 4 square advice
cqtestk4xs at aol.com
cqtestk4xs at aol.com
Wed Nov 15 12:31:46 EST 2017
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 at kk9a.com" <john at kk9a.com>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] 4 square advice
Message-ID: <f5ee6836470d1334f0cb0183431e7297.squirrel at 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 at contesting.com>
To: towertalk <towertalk at contesting.com>
Sent: Wed, Nov 15, 2017 2:37 pm
Subject: TowerTalk Digest, Vol 179, Issue 25
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Today's Topics:
1. Re: 4 square advice (john at 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 at 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 at kk9a.com" <john at kk9a.com>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] 4 square advice
Message-ID: <f5ee6836470d1334f0cb0183431e7297.squirrel at 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 at contesting.com
Subject: Re: [TowerTalk] 4 square advice
From: Jim Brown <jim at audiosystemsgroup.com>
Reply-to: jim at audiosystemsgroup.com
Date: Sun, 12 Nov 2017 10:25:13 -0800
On 11/12/2017 7:35 AM, john at 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 at ac0c.com>
To: <john at kk9a.com>, <towertalk at contesting.com>
Subject: Re: [TowerTalk] 4 square advice
Message-ID: <BECBCF92E2884E22B156E79696EFE16A at 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 at kk9a.com
Sent: Tuesday, November 14, 2017 1:36 PM
To: towertalk at 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 at contesting.com
Subject: Re: [TowerTalk] 4 square advice
From: Jim Brown <jim at audiosystemsgroup.com>
Reply-to: jim at audiosystemsgroup.com
Date: Sun, 12 Nov 2017 10:25:13 -0800
On 11/12/2017 7:35 AM, john at 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 at 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 at earthlink.net>
To: Tower Talk <towertalk at contesting.com>
Subject: Re: [TowerTalk] Help with Force 12 C3S 10-Meter Adjustments
Message-ID:
<856509029.11972.1510690435141 at 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 at mchsi.com>
To: towertalk at contesting.com, moon-net at mailman.pe1itr.com,
TestEquipTrader at yahoogroups.com
Subject: [TowerTalk] OT. FS Tower & Coax Grounding-Sealing Kits
Message-ID: <3e792596-bce6-4e74-2c8a-fc4c11f40989 at 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 $20 per kit. A USPS medium or large flat rate
box would work well here for 4-6 of them unless someone wanted to
purchase all of them, in which case I would need to put them all in a
slightly larger box and ship via FedEx, USPS, etc. PayPal works aok for me.
Gedas, W8BYA
Gallery at http://w8bya.com
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
------------------------------
Message: 5
Date: Tue, 14 Nov 2017 18:19:14 -0500
From: <john at kk9a.com>
To: <towertalk at contesting.com>
Subject: Re: [TowerTalk] OT. FS Tower & Coax Grounding-Sealing Kits
Message-ID: <00aa01d35d9e$ff6ce960$fe46bc20$@com>
Content-Type: text/plain; charset="us-ascii"
LDF12 is HUGE coaxial cable!
John KK9A
To: towertalk at contesting.com, moon-net at mailman.pe1itr.com,
TestEquipTrader at yahoogroups.com
Subject: [TowerTalk] OT. FS Tower & Coax Grounding-Sealing Kits
From: Gedas <w8bya at 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 $20 per kit. A USPS
medium or large flat rate box would work well here for 4-6 of them unless
someone wanted to purchase all of them, in which case I would need to put
them all in a slightly larger box and ship via FedEx, USPS, etc. PayPal
works aok for me.
Gedas, W8BYA
------------------------------
Message: 6
Date: Tue, 14 Nov 2017 15:26:21 -0800
From: "Chris Hoelzle" <choelzle at cox.net>
To: <TowerTalk at contesting.com>
Subject: [TowerTalk] Ground wire between tower and ground stakes
Message-ID: <000901d35d9f$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 at cox.net
Bandon, OR
------------------------------
Message: 7
Date: Tue, 14 Nov 2017 19:03:34 -0500
From: Gedas <w8bya at mchsi.com>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] OT. FS Tower & Coax Grounding-Sealing Kits
Message-ID: <cc9856ff-443a-d31b-3b92-b679a07cfa18 at 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 at kk9a.com wrote:
> LDF12 is HUGE coaxial cable!
>
> John KK9A
>
>
>
> To: towertalk at contesting.com, moon-net at mailman.pe1itr.com,
> TestEquipTrader at yahoogroups.com
> Subject: [TowerTalk] OT. FS Tower & Coax Grounding-Sealing Kits
> From: Gedas <w8bya at 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 at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
------------------------------
Message: 8
Date: Tue, 14 Nov 2017 19:03:16 -0500
From: Steve Maki <lists at oakcom.org>
To: towertalk <towertalk at contesting.com>
Subject: Re: [TowerTalk] OT. FS Tower & Coax Grounding-Sealing Kits
Message-ID: <406d175e-2b44-2722-51ac-f991cdaf126c at 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 at 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 at fastmovers.biz>
To: Towertalk Reflector <towertalk at contesting.com>
Subject: Re: [TowerTalk] Ground wire between tower and ground stakes
Message-ID: <8320B302-33CB-4EE1-BEAC-304B2F1EFE3D at 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 at cox.net
Bandon, OR
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk at 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 at windstream.net>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Ground wire between tower and ground stakes
Message-ID: <9b264e89-921c-3758-03f5-da8a56527ac3 at 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 at cox.net
> Bandon, OR
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
------------------------------
Message: 11
Date: Wed, 15 Nov 2017 08:29:48 -0500
From: Dick's <rcblumen at centurylink.net>
To: Chris Hoelzle <choelzle at cox.net>
Cc: TowerTalk at contesting.com
Subject: Re: [TowerTalk] Ground wire between tower and ground stakes
Message-ID: <7A0CEDF6-55C1-4A76-A2C2-AB6ED9B64EE2 at 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 at cox.net
> Bandon, OR
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
------------------------------
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