[SJDXA] West Creek TX Array Issues and Install Status Report

Sun Nov 13 20:53:54 EST 2011

Hi All....

We had good weather, and we accomplished about 70% of what we hoped today.

1.  Acom 2S1 switch test was a complete success with the 2 K3s and the AL811H amp.  

2.  The loop and NE sloper are about 85% complete.   If you were unaware, the pull ropes have been moved up the tower about 50 feet, so the geometry of the array has changed, and therefore how it is installed has be be relearned by trial and error (e.g. what guy sets have to be crossed, etc).  A few adjustments are  still needed, in particular the attachment point away from the tower must be moved further out by 55 to 75 feet to achieve the needed angle of the radiators.  Right now the NE antenna is about 60 khz wide, but this will improve when we get the geometry zeroed in.  Thanks to W2CG, W1GD, K2TW, and N2HM for their MANY HOURS of discomfort spent in the marsh today.

3.  As a result of the issues faced with raising the the NE TX antenna, the SW/W element of the TX array did not get installed today.  Fortunately there are no guy wire issues so this should go somewhat faster and with less complicationsd.

4.  As you know its been an active weather year....lots of wind and rain.  Many trees came down in the woods, and as a result there were many repairs to be made to the beverages.  Every beverage had at least one large tree fall, and some as many as 4 or 5.  At this point only the SW and NW beverages haven't been walked in their entire length.  All of the Beverages have transformers and feedlines installed.  The key S, W, and NE antennas are all fully in the air and ready.  Thanks to W2ARP for his assistance.

5.  We did not work on the backup Inverted L TX antenna today.  

Still plenty to do between now and 2100z on December 2nd - when ARRL 160 begins.

I understand there will be a shack rewiring party on Thursday.  Details from N2OO to follow.

73,

John W2GD

From: n2oo at comcast.net
To: sjdxa at mailman.qth.net
Date: Sat, 12 Nov 2011 14:39:54 -0500
Subject: [SJDXA] FW: West Creek Array Issues and Install

SJDXA members;
Work Party reminder. See below. John has asked for help tomorrow at the site (Sunday).
Meet time 9:00 AM
We should have a nice day.
(I have a prior commitment to attend an Eagle Scout court of honor and will have to leave early (10am) , but I will be there at 9am with ARP and Gerry W1GD to test the Acom 2S1 with 2 K3’s and one amp (will use the AL811H). We’ll do it on 80 or 40 I guess.)
Also, we can run the same test using a K3 and our MKV. Should work as well.

Yes, I have an extra screw anchor.

Bob W2ARP maybe you can set the shack up for testing the two 160 antennas (see below) with the MKV or with Gerry’s K3. I’ll be bringing mine back home after we run the 2S1 test.

See ya' in the Pileups!
73!
Bob Schenck, N2OO
President SJDXA
GO SJDXA!!! www.sjdxa.org

From: John Crovelli [mailto:w2gd at hotmail.com] 
Sent: Saturday, November 12, 2011 1:24 PM
To: w1gd at aol.com; K2TW; Marty Grozinski; N2OO; N2HM
Subject: RE: West Creek Array Issues and Install
Importance: High

I gather the top element of each sloper is supposed to be spaced roughly 20 feet from the loop at least the NE works out to be this distance.

MARTY and BOB:  note 1GD's comments about placement of the NE element tieoff point out in the marsh - 50 feet further out per his geometry exercise.....do we have another screw in anchor to put out there?

So it would follow the West sloper should be the same distance from the loop.  But since the loop is further away on the opposite side of the tower, I would seem to me the length of the leader rope attached to the West  pull up rope should be somewhat shorter, instead of 30 feet, maybe 15 to 20 feet, to maintain the correct West element spacing relative to the loop.   The height of the element does not have to be the exactly the same as the NE element...eg. 208 feet.  It can be a little higher without issues I think.

Feedline extensions are made and tested and in my car.  

Lets mount some small pulleys at 30 feet with closed loop ropes to allow easy lowering/adjustment of the bottom of the driven elements.  As 1GD pointed out we don't want to be climbing in the winter cold just for a minor tweak. 

Looks like we need at least two additional 100 foot runs of nylon rope.  If you have rope .... bring it.

BOB, we'll need at least one if not TWO SJDXA guys out in the swamp to help with  the TX antenna install.  Hope Randy is available...maybe Bob too.

SEE all at 9 am.  tomorrow.

Bob, if you could set up the shack for testing antennas with the FT1000 that would be very good.....maybe set it up with a coax switch to make it easy to switch back and forth.between the two yagis.

2GD/3

To: w2gd at hotmail.com; k2tw at arrl.net; w2cg at comcast.net
Subject: West Creek Array
From: w1gd at aol.com
Date: Sat, 12 Nov 2011 10:13:05 -0500

As promised, these are "important" measurements (used in the modeling) for the loop/sloper installation:

Loop:  

Top is up 230 feet and 2 feet away from the tower.  (Reality is that we can pull the top pretty much up to the pulley on the new yard arm.)

Bottom is up around 69 feet and approximately 18 feet from the tower.  (Note, we're not changing the shape or dimensions of the existing loop.  We will have to get the loop over the 5th level of guys.  I think this will take some work to raise the loop with the base open and then lower the loop enough to close up the loop base.)

NE Sloper:

Top is up at 208 feet (i.e., 22 feet below the top of the loop) and out about 24 feet from the tower.  I think we need a 30 foot rope from the top of the loop to the sloper insulator to make this work.

Bottom should be about 23 feet up although we may want to try it at a more easily manageable height like 8-10 feet for adjustments.

We need to move the far en anchor point at least 40 feet further out (50 feet would be better) to make the geometry work.  This means moving the anchor or putting in a new one.

W Sloper

Top is at 208 feet (same level as NE sloper) and 20 feet from the tower.

Bottom should be about 23 feet up (or same as NE sloper)

I'm sure we'll need a new anchor point for the far rope.  From what I recall of the trees out therre, this could be our biggest obstacle.

See you all Sunday morning.

Gerry, W1GD
______________________________________________________________ SJDXA mailing list Home: http://mailman.qth.net/mailman/listinfo/sjdxa Help: http://mailman.qth.net/mmfaq.htm Post: mailto:SJDXA at mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html 		 	   		  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.qth.net/pipermail/sjdxa/attachments/20111113/41cc711c/attachment.html 