[TowerTalk] TowerTalk Digest, Vol 167, Issue 56
robert
wa1fcn at charter.net
Mon Nov 28 19:42:15 EST 2016
GM Mike
I believe Marv N5AW uses one on 80 with very good results.
It might be worth an E-mail to get some info.
BoB WA1FCN
On 11/28/2016 4:35 PM, towertalk-request at contesting.com wrote:
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> Today's Topics:
>
> 1. Spacing at center of K1WA/K3LR array (Mike Smith VE9AA)
> 2. Re: Spacing at center of K1WA/K3LR array (jimlux)
> 3. Re: Spacing at center of K1WA/K3LR array (jimlux)
> 4. four square array tuning (Steve Bookout)
> 5. Re: four square array tuning (Peter Voelpel)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Mon, 28 Nov 2016 15:10:55 -0400
> From: "Mike Smith VE9AA" <ve9aa at nbnet.nb.ca>
> To: <towertalk at contesting.com>
> Subject: [TowerTalk] Spacing at center of K1WA/K3LR array
> Message-ID: <007f01d249ab$25a8cb20$70fa6160$@nbnet.nb.ca>
> Content-Type: text/plain; charset="us-ascii"
>
> Greeting Antenna Gurus,
>
>
>
> Put the finishing touches on a 100% homebrew K1WA/(K8UR) K3LR type 5-dipole
> sloping dipole (all parasitic) array for 15m only hours before the contest
> this weekend and came away quite disappointed.
>
>
>
> NE/NW/SE/SW dples are all spaced at 90* from one another but the 5th dipole
> (south) is squeezed in between the normal SE and SW directions. Maybe it's
> too close. Carib stns were louder when beaming AFRICA than they were when
> beaming south. This was all weekend, so I don't think it was an anomaly. I
> haven't done field strength pattern testing yet (no time) but I know it
> won't be pretty. My little A3S at 24' was usually louder on 15m than the
> array. (not 100% of the time, but most of the time.)
>
>
>
> This is built almost EXACTLY like Tim's 4-element 160m array at K3LR (or
> like his array was in the 1990's anyways - not sure if he still uses it.)
> except I used the 5th dipole due south for Caribbean/SA and my 5 radials are
> on the ground, and not raised. Phasing lines, tops with ropes, etc. all the
> same. Most of the mast is PVC (except the bottom 12'_) and the bottoms of
> the dipoles are off the ground maybe 6' (not overlapped at the tower bottom
> like Tims). Box and coax grounded, radials attached. All per his article.
>
>
>
> What I would like to know from anyone that has either built one for 10-15 or
> 20m (or any band, and I'll do the math) is what is the actual spacing used
> dipole center to dipole center?
>
> Or anyone that knows antenna modeling programs, can you see if this has any
> useful gain or F/B with only 6.66' spacing at the centers at 21.1MHz. (which
> is roughly 0.142WL I believe)
>
>
>
> I went this close because all the hardware was taken from an old 6m array
> that I used many moons ago.
>
> I am thinking I should rebuild it with a much larger spacing, maybe around
> .25WL(11.6') and ditch the south and extra, 5th dipole.
>
>
>
> Tnx
>
>
>
> Mike VE9AA
>
>
>
>
>
>
>
> Mike, Coreen & Corey
>
> Keswick Ridge, NB
>
>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Mon, 28 Nov 2016 11:34:22 -0800
> From: jimlux <jimlux at earthlink.net>
> To: towertalk at contesting.com
> Subject: Re: [TowerTalk] Spacing at center of K1WA/K3LR array
> Message-ID: <e6d9d374-72dc-109b-bbb9-127baa9d271d at earthlink.net>
> Content-Type: text/plain; charset=windows-1252; format=flowed
>
> On 11/28/16 11:10 AM, Mike Smith VE9AA wrote:
>> Greeting Antenna Gurus,
>>
>>
>>
>> Put the finishing touches on a 100% homebrew K1WA/(K8UR) K3LR type 5-dipole
>> sloping dipole (all parasitic) array for 15m only hours before the contest
>> this weekend and came away quite disappointed.
>>
>>
>>
>> NE/NW/SE/SW dples are all spaced at 90* from one another but the 5th dipole
>> (south) is squeezed in between the normal SE and SW directions. Maybe it's
>> too close.
> What's connected to the unused dipoles? Coax to a double pole switch,
> like in the 1994 QST article, so that you basically have a open
> circuited stub?
>
> The article comments on the large change in F/B in the model as the
> transmission line parameters were changed (which isn't surprising.. it
> affects the phase on the "parasitic" elements.
>
>
>
> . (not 100% of the time, but most of the time.)
>>
>>
>> This is built almost EXACTLY like Tim's 4-element 160m array at K3LR (or
>> like his array was in the 1990's anyways - not sure if he still uses it.)
>> except I used the 5th dipole due south for Caribbean/SA and my 5 radials are
>> on the ground, and not raised. Phasing lines, tops with ropes, etc. all the
>> same. Most of the mast is PVC (except the bottom 12'_)
> Since the dipoles are vertical, I would expect that in K3LR's case there
> was a fair amount of interaction with the conductive mast. That's
> something you'd need to factor in.
>
>
> and the bottoms of
>> the dipoles are off the ground maybe 6' (not overlapped at the tower bottom
>> like Tims). Box and coax grounded, radials attached. All per his article.
>>
>>
>>
>> What I would like to know from anyone that has either built one for 10-15 or
>> 20m (or any band, and I'll do the math) is what is the actual spacing used
>> dipole center to dipole center?
>>
>
> In K3LRs, assuming that the angles are all 45s, the distance from the
> tower to the feedpoint is 93 ft, and 93 feet from the top of the tower.
>
> That makes the "feedpoint to feedpoint" distance, pretty much the same
> as the distance along the hypotenuse from top to feed, 135 feet (41.15
> meters)
> At 1.84MHz (K3LRs apparent design frequency) the wavelength is 163
> meters, so the center to center distance is pretty close to a 1/4
> wavelength.
>
>
>
>
>> Or anyone that knows antenna modeling programs, can you see if this has any
>> useful gain or F/B with only 6.66' spacing at the centers at 21.1MHz. (which
>> is roughly 0.142WL I believe)
>>
> That is "very close" and almost certainly interacting.
>
>
>>
>> I went this close because all the hardware was taken from an old 6m array
>> that I used many moons ago.
>>
>> I am thinking I should rebuild it with a much larger spacing, maybe around
>> .25WL(11.6') and ditch the south and extra, 5th dipole.
> That would be a start, but this is one of those antennas where some
> modeling will help a lot.
>
> Bear in mind that for most arrays, gain is fairly tolerant of phasing
> errors, but F/B (null depth) is VERY picky. If the phase in the
> parasitic element is off, then the null goes away. That's illustrated in
> Figures 3 & 4 in the original article.
>
>
>
>
>
>
>>
>>
>> Tnx
>>
>>
>>
>> Mike VE9AA
>>
>>
>>
>>
>>
>>
>>
>> Mike, Coreen & Corey
>>
>> Keswick Ridge, NB
>>
>>
>>
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>
>
> ------------------------------
>
> Message: 3
> Date: Mon, 28 Nov 2016 12:46:02 -0800
> From: jimlux <jimlux at earthlink.net>
> To: towertalk at contesting.com
> Subject: Re: [TowerTalk] Spacing at center of K1WA/K3LR array
> Message-ID: <3130d07e-f756-d5f8-00f1-9fd2233100a1 at earthlink.net>
> Content-Type: text/plain; charset=windows-1252; format=flowed
>
> On 11/28/16 11:34 AM, jimlux wrote:
>> On 11/28/16 11:10 AM, Mike Smith VE9AA wrote:
>>> Greeting Antenna Gurus,
> Here's the model
>
> CM Tower with 4 vertical V dipoles ' Comment cards
>
> CM based on K3LR's article in 1994 QST
>
> CE
> ' End of comment
>
> '
>
> SY TH=190/3.28'tower height
>
> SY TR=1/3.28 'Tower Radius
>
> SY DL=131/3.28 'Dipole element length
>
> SY DA=45 'dipole angle
>
> SY DR=.001 'Dipole radius (1mm)
>
> SY DS=95/3.28 'Spacing from tower for center of dipole
>
> SY DH=95/3.28 'height of dipole center above ground
>
> SY FL=175/.78/3.28 'Feedline length
>
> GW 101 101 -sin(DA)*DL 0
> cos(DA)*DL 0 0 .1 DR
> ' Wire 1, upper part
>
> GW 111 101 0 0 -0.1
> -sin(DA)*DL 0 -cos(DA)*DL DR
>
> GW 121 1 0 0 0.1
> 0 0 -0.1 DR 'feedpoint
>
> GW 122 1 1 0 0.05
> 1 0 -0.05 .001
>
> GM 0 0 0 0 0
> DS 0 DH 0
> 'move dipole away from tower and up to height
>
> GM 100 3 0 0 90
> 0 0 0 'make 4 copies
>
> GW 900 100 0 0 0
> 0 0 th tr 'tower
>
> GE 1
>
> '
>
> GN 2 0 0 0
> 13 0.005
>
> EX 0 122 1 00 1
> 0
> ' Voltage source (1+j0) at wire 1 segment 51
>
> TL 121 1 122 1 50
> FL 'transmission line
>
> TL 221 1 222 1 50
> FL
>
> TL 321 1 322 1 50
> FL
>
> TL 421 1 422 1 50
> FL
>
> LD 5 0 0 0
> 58000000 '20% of copper (steel)
>
> LD 5 900 0 0
> 37700000 'Tower
>
> LD 0 222 1 1 1e6
>
> LD 0 322 1 1 1e6
>
> LD 0 422 1 1 1e6
>
> '
>
> FR 0 1 0 0
> 1.84 0
> ' Set design frequency (300 Mc).
>
> '
>
> EN
>
>
>
> ------------------------------
>
> Message: 4
> Date: Mon, 28 Nov 2016 17:27:52 -0500
> From: Steve Bookout <steve at nr4m.com>
> Cc: towertalk at contesting.com
> Subject: [TowerTalk] four square array tuning
> Message-ID: <ac33556d-1cc8-2946-e3fc-7fb1022ff146 at nr4m.com>
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> Hello all,
>
> Over the last few years, I have added four square arrays for 40 meters
> and 80 meters, and both work really outstanding.
>
> Recently, I added a third one for 20 meters and am having a difficult
> time with it.
>
> Short version is I resonated each antenna individually, with the others
> shorted with clip leads to gnd, to 13.9 MHz +/-. The array, as a whole,
> doesn't show a suitable SWR until 15.6 MHz! Like the others I had
> installed, I was expecting a 150 KHz, or so, rise in frequency to
> resonance. I do understand that it's really all about the power being
> dumped to the dummy load, but the amp is not going to tolerate a 3.5 to
> 1 SWR.
>
> Cables were cut using an AIM antenna analyzer and were double checked.
> All other cable/parts were checked out and shown to be correct.
>
> 80 ground mounted radials under each antenna.
>
> Built just like I did the other two.
>
> Gonna look at it with an O-scope tomorrow and check phase vs freq. My
> gut feeling is an incorrect value component.
>
> My gut feeling aside, I would appreciate any ideas.
>
> 73 de Steve, NR4M
>
>
>
> ------------------------------
>
> Message: 5
> Date: Mon, 28 Nov 2016 23:36:04 +0100
> From: "Peter Voelpel" <dj7ww at t-online.de>
> To: "'Steve Bookout'" <steve at nr4m.com>
> Cc: <towertalk at contesting.com>
> Subject: Re: [TowerTalk] four square array tuning
> Message-ID: <526922D7450D42F2953133F45AA279DB at SHACK>
> Content-Type: text/plain; charset="us-ascii"
>
> Hi Steve,
>
> You need to OPEN the unused radiators while you adjust one at the time!
>
> If connected to ground they couple to the radiator in tune.
>
> 73
> Peter, DJ7WW
>
> -----Original Message-----
> From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of Steve
> Bookout
> Sent: Montag, 28. November 2016 23:28
> Cc: towertalk at contesting.com
> Subject: [TowerTalk] four square array tuning
>
> Hello all,
>
> Over the last few years, I have added four square arrays for 40 meters
> and 80 meters, and both work really outstanding.
>
> Recently, I added a third one for 20 meters and am having a difficult
> time with it.
>
> Short version is I resonated each antenna individually, with the others
> shorted with clip leads to gnd, to 13.9 MHz +/-. The array, as a whole,
> doesn't show a suitable SWR until 15.6 MHz! Like the others I had
> installed, I was expecting a 150 KHz, or so, rise in frequency to
> resonance. I do understand that it's really all about the power being
> dumped to the dummy load, but the amp is not going to tolerate a 3.5 to
> 1 SWR.
>
> Cables were cut using an AIM antenna analyzer and were double checked.
> All other cable/parts were checked out and shown to be correct.
>
> 80 ground mounted radials under each antenna.
>
> Built just like I did the other two.
>
> Gonna look at it with an O-scope tomorrow and check phase vs freq. My
> gut feeling is an incorrect value component.
>
> My gut feeling aside, I would appreciate any ideas.
>
> 73 de Steve, NR4M
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
>
>
> ------------------------------
>
> Subject: Digest Footer
>
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>
>
> ------------------------------
>
> End of TowerTalk Digest, Vol 167, Issue 56
> ******************************************
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