Copper Talk » Ask The Tech » Antennas » Inverted V Question????????? « Previous Next »

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

Snapperhead
Member
Username: Snapperhead

Post Number: 166
Registered: 2-2002
Posted on Sunday, October 31, 2004 - 7:32 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

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
Top of pagePrevious messageNext messageBottom of page Link to this message

Dindin
Intermediate Member
Username: Dindin

Post Number: 422
Registered: 2-2004


Posted on Sunday, October 31, 2004 - 8:28 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

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.
Top of pagePrevious messageNext messageBottom of page Link to this message

Gonzo
Member
Username: Gonzo

Post Number: 85
Registered: 9-2004
Posted on Monday, November 01, 2004 - 10:11 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

"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
Top of pagePrevious messageNext messageBottom of page Link to this message

Snapperhead
Intermediate Member
Username: Snapperhead

Post Number: 167
Registered: 2-2002
Posted on Monday, November 01, 2004 - 9:04 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

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.
Top of pagePrevious messageNext messageBottom of page Link to this message

Snapperhead
Intermediate Member
Username: Snapperhead

Post Number: 168
Registered: 2-2002
Posted on Monday, November 08, 2004 - 8:23 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

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
Top of pagePrevious messageNext messageBottom of page Link to this message

Tech833
Moderator
Username: Tech833

Post Number: 884
Registered: 8-2002
Posted on Monday, November 08, 2004 - 8:55 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

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!
Top of pagePrevious messageNext messageBottom of page Link to this message

Highlander
Advanced Member
Username: Highlander

Post Number: 672
Registered: 12-2001
Posted on Monday, November 08, 2004 - 2:29 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

How do you ground coax?
Top of pagePrevious messageNext messageBottom of page Link to this message

Snapperhead
Intermediate Member
Username: Snapperhead

Post Number: 169
Registered: 2-2002
Posted on Monday, November 08, 2004 - 11:50 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

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
Top of pagePrevious messageNext messageBottom of page Link to this message

Tech833
Moderator
Username: Tech833

Post Number: 887
Registered: 8-2002
Posted on Tuesday, November 09, 2004 - 2:31 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

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.
Top of pagePrevious messageNext messageBottom of page Link to this message

Mgrant
New member
Username: Mgrant

Post Number: 2
Registered: 11-2004
Posted on Saturday, November 13, 2004 - 11:37 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

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

Add Your Message Here
Post:
Username: Posting Information:
This is a private posting area. Only registered users and moderators may post messages here.
Password:
Options: Enable HTML code in message
Automatically activate URLs in message
Action: