Author |
Message |
Rollingrock
New member Username: Rollingrock
Post Number: 4 Registered: 3-2004
| Posted on Tuesday, March 09, 2004 - 5:55 am: |
|
Can it be done? If yes can anyone send me plans or specs for building one? I could lay it out in an inverted vee probably 1/2 wave center fed since a full would probably be huge. Any suggestions? |
Bruce
Senior Member Username: Bruce
Post Number: 1061 Registered: 9-2003
| Posted on Tuesday, March 09, 2004 - 11:16 am: |
|
Here's a starter web site http://www.amwindow.org/tech/htm/tenmant/tenmant.htm |
Allagator
Intermediate Member Username: Allagator
Post Number: 241 Registered: 9-2002
| Posted on Tuesday, March 09, 2004 - 7:37 pm: |
|
Rollingrock here is a link i like to use all the time ! and Yes it can be done i have 2 in the air rite now one in a tree and one inside a pvc pipe on a rotor !!! he he one i had to try too !!!http://www.angelfire.com/mb/amandx/dipole.htmlry !!! |
Highlander
Intermediate Member Username: Highlander
Post Number: 440 Registered: 12-2001
| Posted on Tuesday, March 09, 2004 - 8:11 pm: |
|
I used to have an 11 meter homebrew dipole in my attic...I could talk to my freind on his base 14 miles away running a similar antenna. Fun stuff! Building your own is very rewarding. We also built a couple of 3 element quads for 2 meters that worked extremely well. |
Dindin
Junior Member Username: Dindin
Post Number: 14 Registered: 2-2004
| Posted on Tuesday, March 09, 2004 - 9:20 pm: |
|
Gator,you need to remove the "ry"off the end of your link |
Rollingrock
New member Username: Rollingrock
Post Number: 7 Registered: 3-2004
| Posted on Wednesday, March 10, 2004 - 1:02 am: |
|
Thanks for the info gents, one more question? Do I need to use a balun or gamma match with this? |
Dindin
Junior Member Username: Dindin
Post Number: 15 Registered: 2-2004
| Posted on Wednesday, March 10, 2004 - 8:09 pm: |
|
Rollingrock, for a wire dipole the easiest balun is constructed using an electrical half wave(18'1/2") of 75 ohm coax,rg6 or rg11.connect the shield to one side of the ant at the center and the center conductor to the other side.be sure to waterproof the coax with clear rtv silicone caulk.the easyest way i have found to terminate the free end of the coax is to use the twist on bnc connectors,male and female from ratshack or other electronic supplier.the shield in most commonly available 75 ohm coax is almost impossable to solder to.for the cb freq's,the measurements for the wire that worked best for me were 108.25 inches for the "hot" side and 113.4 inches for the ground side.most importantly check the swr before setteling down and "shooting skip"!swr on these are set by adjusting the physical lengh of the"hot"side. good luck,happy dx'ing and 73's from Dindin,cef291in the buckeye |
Rollingrock
New member Username: Rollingrock
Post Number: 9 Registered: 3-2004
| Posted on Thursday, March 11, 2004 - 11:48 pm: |
|
Dindin, this may sound foolish but is this for the feed (the 75 ohm coax)or is this in addition to the feed? Does this term at the radio or is it hangin in free space? If it does hang do I need to coil it? Sorry but antennas aren't my strong point. |
Dindin
Junior Member Username: Dindin
Post Number: 16 Registered: 2-2004
| Posted on Friday, March 12, 2004 - 8:58 pm: |
|
Rollingrock, The 75ohm would be the feed for the antenna.Your 50 ohm feedline would connect to it in turn.I have experimented with coiling the balun but have not seen any advantage.When a dipole is hung horizontal its polarity will match about all over the air tv antennas which will increase the chances for tvi.Hanging them vertically lessens this effect.A good example of a commercialy manufactured dipole was the A.S.Super Scanner.it consisted of three dipoles switched for its directional gain.In the early 80's,my dad and I scratch built a modified super scanner.(heavier relays,wider spacing and heavier construction)With a maverick 250 and the SBE I currently run it made up a world wide talking station.I will always believe "Antenna IS Everything!"in this hobbie. |