| Author |
Message |
    
Mrclean
Junior Member
Username: Mrclean
Post Number: 26
Registered: 12-2003
| | Posted on Thursday, February 02, 2006 - 5:46 pm: | 
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I have permission to install a wire antenna to a structure about 1000 ft from my house and about 100 ft up. It will be about 35 40 ft on my end. What kind of antenna would you use andwhat would be a sufficent ground? Also what is a good ground and whats best way to disapate static to ground? |
Tech833
Moderator
Username: Tech833
Post Number: 1183
Registered: 8-2002
| | Posted on Thursday, February 02, 2006 - 9:35 pm: |
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Are you planning on using this to transmit, or receive only? What band(s)? |
Mrclean
Junior Member
Username: Mrclean
Post Number: 27
Registered: 12-2003
| | Posted on Friday, February 03, 2006 - 3:23 am: |
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Just going to use it on 11 meter |
Tech833
Moderator
Username: Tech833
Post Number: 1189
Registered: 8-2002
| | Posted on Friday, February 03, 2006 - 10:50 am: |
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Then you certainly do not want the wire to be longer than 18 feet. In that case, you need to feed it with some matching network.
Otherwise, ask if you can run coax to that structure and then simply mount a Maco on top of it.
A longwire antenna works GREAT for receiving, but is really horrible for transmitting except for the real low bands like 80 or 160 meters.
I only have a longwire at my house, and it calculates to about -14 dB gain on 11 meters. Using my longwire, I would have to run about 100 watts to have the same signal I could with 4 watts on a 102" whip. |
Georgeodjungle
Junior Member
Username: Georgeodjungle
Post Number: 10
Registered: 1-2006
| | Posted on Friday, February 03, 2006 - 2:08 pm: |
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lomgwires rule if you do it right.
i run 2 rhombic antennas.
one pionting se & e.
there 2 to 6 # over my I-2000 when the skip is in.
i gain is insain.
the long wires don't talk vary good for local at all.
mostly because there horizontal.
right now i'm playing with beverage antenna.
again, not a great local talker, but dx?
just like a big radio.
there's lots of great sites out here to point you in the right direction.
just profusion or google it.
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Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1221
Registered: 7-2004
| | Posted on Friday, February 03, 2006 - 6:03 pm: |
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Hey- watch out for that treeeeeeeee! |
Kj7gs
Junior Member
Username: Kj7gs
Post Number: 40
Registered: 12-2004
| | Posted on Sunday, February 05, 2006 - 3:45 pm: |
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What kind of transmission line are you planning to use for that kind of distance to the feedpoint? |
Georgeodjungle
Junior Member
Username: Georgeodjungle
Post Number: 14
Registered: 1-2006
| | Posted on Monday, February 06, 2006 - 12:17 am: |
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just like any other antenna ,base or moble, bigger is best.
if you have 1000'? run it!!!!
look up "beverage or long wire antenna"
me my self, i run 2 rombics.
basically there a horizontal full wave 4 element beam.
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Mrclean
Junior Member
Username: Mrclean
Post Number: 28
Registered: 12-2003
| | Posted on Monday, February 06, 2006 - 3:44 am: |
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Most antennas recieve and transmit about the same. Always heard that beverage antennas were different in that they recieve much better than they transmit. Now a Rhombic would be very nice. How big are your rhombics? |
Georgeodjungle
Junior Member
Username: Georgeodjungle
Post Number: 15
Registered: 1-2006
| | Posted on Monday, February 06, 2006 - 1:31 pm: |
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there 144' of wire.
but actual size is 60' x 35' & 36' up in the air.
there abouts.
the math is kind of funny,
i don't know the gain.
with realy low swr and flat on some freqs
i'd say some where around 20db?
all of the web sites say some thing a lil different.
what direction or area would you piont it?
cuz i talk to my dad & he's mostly around az & tx in the winter.
se from here.
and my daughter in pa.
east from here.
but actualy there 75 and 120 deg.
i need like 4 more to CONTROL THE WORLD !!!!
or at least to talk to them.
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Tech833
Moderator
Username: Tech833
Post Number: 1199
Registered: 8-2002
| | Posted on Tuesday, February 07, 2006 - 12:18 am: |
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You guys are overlooking the problem with running longwire antennas- Peaks and nulls all over the place. 'Longer is better' only goes for receive antennas.
Also, you should know that beverage antennas are HIGHLY directional toward the far end of the wire. It is like having a beam you cannot turn.
Since I don't have the energy to go into it real far (way too much to cover), why don't you just do what the other less experienced antenna gurus have told you and then report back to us here what happens. |
Georgeodjungle
Junior Member
Username: Georgeodjungle
Post Number: 16
Registered: 1-2006
| | Posted on Tuesday, February 07, 2006 - 2:46 am: |
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yep:
same with the rombics.
not that easy to turn.
the beverage works o.k. it's pointed north.
i think it would do better if i didn't end it on a tree.
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Rldrake
Member
Username: Rldrake
Post Number: 57
Registered: 1-2006
| | Posted on Tuesday, February 07, 2006 - 4:11 am: |
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Tree won't bother it any, but a reasonable standoff should be between it and tree for electrical and/or fire safety. |
Tech833
Moderator
Username: Tech833
Post Number: 1200
Registered: 8-2002
| | Posted on Tuesday, February 07, 2006 - 9:37 am: |
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Drake, I think he was referrring to the tree being a problem for the termination. A true beverage antenna is fed with something like a 10:1 balun and then the far end of the antenna has a load balancing resistor (500 ohms if fed with a 10:1 balun, 450 ohms if fed with a 9:1). This makes the antenna sorta like a super lossy 'dummy load'. It also means that the coax impedance and antenna impedance will always be really close. The resistor at the far end also bleeds off a lot of static noise.
If the far end is in a tree, then the ground lead between the resistor and ground becomes part of the antenna and makes it hard to balance it well over a broad range. Having the load resistor right next to the ground works best. |
Georgeodjungle
Junior Member
Username: Georgeodjungle
Post Number: 26
Registered: 1-2006
| | Posted on Friday, February 10, 2006 - 7:40 pm: |
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trees do hinder.
there full of water.
not a good transmitting medium.
and if you terminate to a tree.
it will work like a battery.
only a volt or so "more in the winter" but still never good to have voltage in your antenna.
ya:
a resistor will work o.k.
the poorer the grounding at termination the better it works.
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