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Message |
    
Parts_man
Junior Member
Username: Parts_man
Post Number: 24
Registered: 2-2004
| | Posted on Saturday, March 20, 2004 - 7:13 am: | 
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I have been thinking about a beam antenna. The free space is kinda limited so the Maco M103C or the Comet that are listed in the Copper are the two main choices. Both of these have a turning radius I need.
Any thougts on going with just singular polor or dual would be welcome. If I went with the M103C I would mount it vertical seeing that my understanding that vert. goes horizontal after so far.
Your thoughts would be appreciated, thanks
parts_man |
Ozzie
Intermediate Member
Username: Ozzie
Post Number: 141
Registered: 11-2003
| | Posted on Saturday, March 20, 2004 - 9:42 am: |
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Have you looked at the Hexbeam?? Has about a 12ft turning radius (I think). If you mount any beam vertical it helps to use a non-conductive support from the tower to the beam - just reduces chances of the mast de-tuning or otherwise causing problems.
Mount it so that the closest element is at least 8ft away from tower - again just helps to make sure it all works the well it's supposed to.
Again I think (havemt read the specs in a couple of years) the Hex Beam is designed to run either/or polarity by switching coax. I was thinking about getting one when I first got here but didnt think the mast (two pieces of PVC pipe, one inside the other) would support it so went for the A99.Now I'm about to raise a tower who knows. |
Parts_man
Junior Member
Username: Parts_man
Post Number: 25
Registered: 2-2004
| | Posted on Saturday, March 20, 2004 - 10:58 am: |
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Ozzie,
Thanks for your input.
Where can I find specs on the hexbeam? My mast it metal on the tower and maybe the vertical would not work too well. |
ELCO Guy. (Unregistered Guest)
Unregistered guest
| | Posted on Saturday, March 20, 2004 - 11:01 am: |
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@ Parts guy
A few thoughts on beam antennas and antennas in general.
Several factors go into making a decision as to which antenna to buy. As you stated turning radius is one. Others include gain, rejection, rotor required, power handling ability etc. So also consider in making your decision the possibility of moving the location so as to allow you to put up a better antenna than you thought.
Item 2 orientation:
You mentioned vertical orientation of the antenna and how it changes. Yes it does change orientation but not when you think. It changes orientation after the first skip bounce ratner than just because of distance. Going up to the "skip zone" in the upper atmosphere the signal retains its orientation. BUT once it bounces and 'skips' it just might change to horizontal. There are no hard fast rules of course. It depends on atmospehric conditions to a large extent. Most Amateurs orientate their beams for High Frequency aka HF operations horizontal because man made noise is mostly vertical orientated. Thus by using a horizontal orientation the reduce their man made noise or QRM somewhat. There is one exception to this. They hams use vertical orientaton for loccal VHF and UHF communications almost exclusively due to the fact that their repeater antennas as well as the mobile antennas are also vertical orientated.
Item 3, distance...
Weither you mount your antenna in a vertical or horizontal configuration does not make any difference as to the distance the signal will travel. Both horizontal and vertical travel equal distances in a non skip communication. The only difference as noted above is the noise factor. Horizontal mode noise canceling allows you to hear better. HOWEVER since most mobiles are vertical orientated your ability to hear local mobiles beyond close range becomes impaired.
So it is six of one and half a dozen of the other.
NOW FOR THE STRANGE...you do not need a beam to make a beam. If you take two quarter wave antennas, mount them at ground level, space them appart at an appropriate distance and feed one of them slightly out of phase you make a BEAM. Well kind of a beam. What you are doing is using one anenna to focus some of the power like a mini beam. The gain will not be as great as a true "Beam Antenna" but it will definately favor transmission and reception of signals from one direction. See the ARRL Handbook or the ARRL Antenna Book for Phased Verticals if you wish to put one of these systems up.
Signed
That ELCO Guy
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Ca346
Advanced Member
Username: Ca346
Post Number: 641
Registered: 8-2003
| | Posted on Saturday, March 20, 2004 - 1:31 pm: |
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Parts Man:
I have a 4 element Quad. (SE Lightning 4+) It is very light (18#) and was easy to install (another factor). Appears to be somewhat (appearance) like the MACO Shooting Star, except the radiating elements are wire. I believe if you can afford the dual polarity option, it is an advantage. Not a HUGE advantage, but there are times when I switch back and forth and it does make a noticable difference.
ELCO GUY:
Join and become a member! There are many hams here with dual interests (Ham+CB)and your input is appreciated.
CA346/CEF197 |
Parts_man
Junior Member
Username: Parts_man
Post Number: 27
Registered: 2-2004
| | Posted on Sunday, March 21, 2004 - 7:10 am: |
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I talked to the owner of the Hex Beam Co. They are designed for horizontal only. He said they could probaly be set up vertical but they had no experience with that.
In the meantime went to ebay and purchased a
PDL-2, thought could'nt get them any more. The Comet was dual polarity and the M103C was just singular. Read some of the other post and liked the PDL-2. Dual polarity and short boom. Quickly gained respect for it with all good things said about it.
Gota wait for it to come from Canada but some of my freinds here say it'll be worth it also.
Thanks for the input Ozzie, ELCO Guy, and Ca346. Maybe I can talk to you when the beam comes in to get a report. Now I have to use the A-99 pogo stick w/ a good deal of power.
Going to try the Net today again for more contacts.
Parts_man--CEF 312 |
Pig040
Intermediate Member
Username: Pig040
Post Number: 344
Registered: 7-2003
| | Posted on Sunday, March 21, 2004 - 10:38 am: |
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You will like the pdl2, I had one of those, it is a nice antenna where space is a factor. I had bad luck with an M103, the pdl2 is what I went to after that and it was a far superior antenna, and doesnt take a rotor that will break the bank to turn it either. |
Bigbob
Senior Member
Username: Bigbob
Post Number: 1781
Registered: 12-2001
| | Posted on Sunday, March 21, 2004 - 2:00 pm: |
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Enamel the fiberglass spreaders,I did not and mine bend to the south,don't know why exactly but was told to paint them and it would stop,turn it north and in a month the arms have bent to south again,weird.Bigbob |
Pig040
Intermediate Member
Username: Pig040
Post Number: 345
Registered: 7-2003
| | Posted on Monday, March 22, 2004 - 9:33 am: |
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Bigbob is right about that, I noticed painfully, when I took mine down that the fiberglass was starting to make splinters. |
Tech808
Moderator
Username: Tech808
Post Number: 1900
Registered: 8-2002
| | Posted on Tuesday, March 23, 2004 - 2:24 am: |
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Bigbob,
When I put the SE Beams up Tech 833 told me to very lightly sand the Fiberglass Spreader's and Coat/Spray them with WHITE FIBERGLASS AUTO PRIMER.
Then after taking down my Anttron 305 to let Redman use it after 7 year's I lightly sanded it and sprayed it also as well as my 2 meter Anttron Base Antenna and now they both look like New Again.
WHITE FIBERGLASS AUTO PRIMER GOOD STUFF. 
Lon
Tech808 |
