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Message |
    
Snapperhead
Member
Username: Snapperhead
Post Number: 166
Registered: 2-2002
| | Posted on Sunday, October 31, 2004 - 7:32 pm: | 
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Hey guys, boy it's been awhile since I've logged on the this great forum....Things have changed...
Anyways, I just moved into a new houseand erected my I-Max 2000. Now I'm getting threats from the CCR regulations about my antenna..Instead of fighting them right now, I want to run something alittle more hidden from view...I was thinking of running a inverted V style antenna. My question is is that I can't really run it up in the air. I can however run it about 30' up on the peak of the roof pitch and come down with the facia or eves of the house, wich is at a 45 Degree angle. Wich means this will be a surface mount install. Will this affect anything in Performance. I plan on using a W2FMI- 1:1 HB 50 Balun........Most of the formulas I've found on the internet are for a Half wave length. For instance it gave me 8.09 inches for each leg...I have about 40 feet to play with on each wire......What if I wanted to go with a bigger wave length, like for instance 1" or 3/4".. If possible what is a good starter length to play with...One other thing, what is a good wire to use, solid copper, Fine stranded insulated, Etc. Any info or input for you guys would be much appreciated......73's all |
Dindin
Intermediate Member
Username: Dindin
Post Number: 422
Registered: 2-2004
| | Posted on Sunday, October 31, 2004 - 8:28 pm: |
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Snapperhead,
first thing I noticed was the dimension,should be 8.09 FEET not inches.you can use 14awg stranded or solid,bare or insulated.whichever is available.ideally its angle should be between 60 and 120 degrees.45degrees should work but will change impedance and the height of the ends has an effect on it also.use an insulated wire the same color as the fascia and the regulating power may never know its there!let us know your results and also expect it to be directional to its broadsides. |
Gonzo
Member
Username: Gonzo
Post Number: 85
Registered: 9-2004
| | Posted on Monday, November 01, 2004 - 10:11 am: |
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"Will this affect anything in Performance."
Unfortunately yes it will. Dindin suggestions are right on the money.
Use 36' per side. But don't expect it to perform like an Imax2000 |
Snapperhead
Intermediate Member
Username: Snapperhead
Post Number: 167
Registered: 2-2002
| | Posted on Monday, November 01, 2004 - 9:04 pm: |
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Hey guys, first off I appoligize on the 8.09 inches, I meant to say feet....Typo ya see.........Well I realize that it wont perform as well as my Imax, but I just need something to get out and chew the rag a little when the DX is rolling.....I'll give Gonzo's advice a shot and start off with 36' (full wave) and hopefully the SWR trimming wont be a pain.....I'll see what I'm dealing with by running a SWR curve on the band and go from there.....I'll keep you posted when I get this Homebrew going.......Thanks for all your help guys.
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Snapperhead
Intermediate Member
Username: Snapperhead
Post Number: 168
Registered: 2-2002
| | Posted on Monday, November 08, 2004 - 8:23 am: |
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Hey guys, I went ahead and and built it without the Balun......I plan on getting one in the next week or so. I took and 12" jumper of coax and soldered it real good to the wires, and went direct feedline. I got some 12 gauge multistrand wire and cut it at around 8' 6" (a little long). I plan on going with some better and longer wire when I get the Balun...I went to peak of roof in the attic and just came down the rafters at 8' 3/4 of an inch, looped 1 time around the insulator and the left over wire just started wrapping it back up towards the feedline. I'm not sure what the pitch is or dergree of the angles of each wire but I just wanted to try it out. When I first checked SWR's it was a 1:4 to 1 match...Heck, I'm happy with that. One thing I noticed was the lack of static noise running the wire...My I-Max picked up alot of that. Signals weren't as strong on the wire compared to my I-Max but I still DX'd alot yesterday with good results....When I get my 1:1 Balun I plan on going running a longer wire and running it completly flat pointing East to West......Hopefully It will be easy to tune.......Just wanted to share my experience with you guys......Thanks again for the info........73's all |
Tech833
Moderator
Username: Tech833
Post Number: 884
Registered: 8-2002
| | Posted on Monday, November 08, 2004 - 8:55 am: |
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Snap,
I am sorry I did not see this thread baefore now. I only saw it when I approved your post above.
SOlid wire seeems to work a little better than stranded on wire TX antennas. Your 45 degree angle is a little shallow, but not too bad at all. The more angle you get, the more omni-directional the antenna will be, and the lower the impedance too.
However, from the sounds of it, you got it close enough to work for you.
An inverted V is quieter than a gain vertical. Expect that. Additionally, the attenuation of your surrounding roofing materials will quiet things down too, in addition to slightly affecting your efficiency.
You may find that the balun oes not change your antenna much. Do not be alarmed. Ground the heck out of your coax! |
Highlander
Advanced Member
Username: Highlander
Post Number: 672
Registered: 12-2001
| | Posted on Monday, November 08, 2004 - 2:29 pm: |
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How do you ground coax? |
Snapperhead
Intermediate Member
Username: Snapperhead
Post Number: 169
Registered: 2-2002
| | Posted on Monday, November 08, 2004 - 11:50 pm: |
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Hey there 833, thanks for the tip........I did pick up some solid 12g solid wire today and plan on tinkerin' around this weekend......I run a Kenwood TS-930s and I do have Base grounded with grounding rod......Do I need to ground the coax as well??? I am throwing a little RF to my phone in the house but it is to be expected......Thanks again.........73's |
Tech833
Moderator
Username: Tech833
Post Number: 887
Registered: 8-2002
| | Posted on Tuesday, November 09, 2004 - 2:31 am: |
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I am truly sorry for the gross spelling errors above.
Here's how you ground coax - http://www.andrew.com/products/trans_line/heliax/sureground.aspx
A great page listing some professional grounding stuff is here - http://www.andrew.com/products/trans_line/heliax/lightning_prot.aspx
Links have been checked. No conflict with Copper Elec. |
Mgrant
New member
Username: Mgrant
Post Number: 2
Registered: 11-2004
| | Posted on Saturday, November 13, 2004 - 11:37 am: |
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You might try cutting the wire to .625-.64 wl on each leg, essentially having a Extended Double Zepp. The gain is about 3 db over a dipole, or equivelant to two phased 5/8 antennas. It can be fed with a 450 ohm ladder line into a tuner, or take a .20 wl (6-7ft) stub of 450 ohm ladder line and feed into a 1:1 balun, then trim the stub for best SWR; probably around 5.5ft. Most EDZs are run flat, but I've seen them as an inverted v, sloper, or even vertical from a tree.
Mgrant |
