[Antennas] RE: Antennas Digest, Vol 16, Issue 11

Sat May 14 22:18:32 EDT 2005

Just curious but if there a chance maybe some RF/EMI might be doing. I ahave 
heard of it while it was plugged in but never during unplugged.

Larry Fields, n6hpx/mm

>
>Message: 2
>Date: Fri, 13 May 2005 14:42:52 -0700
>From: "Gary Morgan" <gmorgan at dock.net>
>Subject: [Antennas] my beam moves itself!
>To: <antennas at mailman.qth.net>
>Message-ID: <002f01c55804$b77663f0$a5263442 at DHXMV211>
>Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>	reply-type=original
>
>i have a problem with my CDE Ham II rotator (purchased used about three
>years ago). it goes like this:
>
>a couple of weeks ago, i noticed that my beam seemed to be moving itself. i
>figured i could check whether the control box was at fault by simply
>unplugging the unit from the electrical outlet.
>
>so the next day, i plugged in the unit, pointed the beam due north for a
>sked, then turned off the control box and unplugged it.
>
>a few hours later, i went outside and looked and the beam had turned itself
>180 degrees and now pointed due south. i repeated this experiment just in
>case i had had something wrong the first time. but, indeed, without power,
>the beam moves itself to due south.
>
>i doubt that the clamps are loose: when i move it back to north, movement 
>is
>same as always and it's not a problem.
>
>i'd be grateful for ideas from anyone about what to do (i know, i 
>know...get
>a new one and use this to anchor a boat somewhere...)...if there's
>reasonable fix, i'd prefer that.
>
>thanks much,
>73s,
>gary
>kd0al
>
>
>
>------------------------------
>
>Message: 3
>Date: Fri, 13 May 2005 17:22:58 -0500 (GMT-05:00)
>From: Billy Cox <aa4nu at ix.netcom.com>
>Subject: Re: [Antennas] my beam moves itself!
>To: Gary Morgan <gmorgan at dock.net>, antennas at mailman.qth.net
>Message-ID:
>	<29926975.1116022979454.JavaMail.root at statler.psp.pas.earthlink.net>
>Content-Type: text/plain; charset=us-ascii
>
>Gary,
>
>Does the indicator follow the beam OK?
>
><If so, then your clamps are probably OK>
>
>Can you have someone operate the control box
>while you are outside to where you can HEAR
>the brake wedge being released? <it's normally
>a 'klunk' sound> You should be able to hear it.
>
>Check for that ... as it seems like the wedge is
>NOT engaged, and the beam is free floating.  Or
>the lower casing is not locking down on the wedge.
>
>The Ham-II had a upgrade ... better wedge and
>lower casing ... seems I upgraded one of mine
>several years ago.
>
>Hope this helps ...
>
>73 Billy AA4NU
>
>-----Original Message-----
>From: Gary Morgan <gmorgan at dock.net>
>Sent: May 13, 2005 4:42 PM
>To: antennas at mailman.qth.net
>Subject: [Antennas] my beam moves itself!
>
>i have a problem with my CDE Ham II rotator (purchased used about three
>years ago). it goes like this:
>
>a couple of weeks ago, i noticed that my beam seemed to be moving itself. i
>figured i could check whether the control box was at fault by simply
>unplugging the unit from the electrical outlet.
>
>so the next day, i plugged in the unit, pointed the beam due north for a
>sked, then turned off the control box and unplugged it.
>
>a few hours later, i went outside and looked and the beam had turned itself
>180 degrees and now pointed due south. i repeated this experiment just in
>case i had had something wrong the first time. but, indeed, without power,
>the beam moves itself to due south.
>
>i doubt that the clamps are loose: when i move it back to north, movement 
>is
>same as always and it's not a problem.
>
>i'd be grateful for ideas from anyone about what to do (i know, i 
>know...get
>a new one and use this to anchor a boat somewhere...)...if there's
>reasonable fix, i'd prefer that.
>
>thanks much,
>73s,
>gary
>kd0al
>
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>
>
>------------------------------
>
>Message: 4
>Date: Fri, 13 May 2005 23:57:26 EDT
>From: W3HKK at aol.com
>Subject: Re: [Antennas] Modeling Help Requested for 2 FD antenna ideas
>To: antennas at mailman.qth.net
>Message-ID: <20d.efe256.2fb6d126 at aol.com>
>Content-Type: text/plain; charset="US-ASCII"
>
>
>Im looking for an 80M antenna to give me radiation in the  30-60 degree 
>range
>for field day, but the max antenna ht will only be around  35-40 ft.
>
>Two thoughts come to mind:
>
>1.  an elongated tilted   rectangular loop 90  ft on top and bottom and  40
>ft on each side.  the loop would  be tilted  at 45 degrees to get the  
>bottom
>wire about 10 ft off  the ground.    My questions are: what would be the 
>max
>radiation  angle   and would it favor the direction of the slope or away 
>from
>it?    Would it perform best  fed in the center or at a  corner, for FD
>purposes...ie for most of the US  on 80M.
>
>Also, how would it perform on 40M?   for  FD  purposes.
>
>2.  An 80m  bob-tail curtain with three qtr wave  vertical elements 
>suspended
>from  two half wave segments at both ends and  the middle.   But since an 
>80M
>bobtail is  66 ft long vertically  and my  max support ht is 35-40 ft, I
>would have to tilt the  vertical  elements at a 45 degree angle.  So we 
>have a 45
>degree tilted bobtail  curtain, in effect.
>
>Same questions as above.  What is the max radiation  angle   and which way
>does it favor.  A conventional  BTC  with 3 vertical elements radiates both
>perpendicular to and in the plane of the  antenna in a clover leaf pattern. 
>  but
>at angles  under 30  degrees.  Im hoping the tilting would raise the max 
>lobe
>to a more  acceptable  45-60 degree range.  The antenna is a direct feed 
>into
>one  corner with 52 ohm coax and yields a 1:1 swr at resonance.
>
>Can anyone help me?   thanks
>
>de Bob  W3HKK
>
>
>
>------------------------------
>
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>
>End of Antennas Digest, Vol 16, Issue 11
>****************************************