Tim, You have two different antennas.
The antenna you describe as the 225 is a directional antenna. It consists of a driven element and a reflector. The pipe you describe is used to secure the mounting clamps. I believe this antenna wants to be mounted so that the tower leg extends above and below the antenna. The pattern will be a cardoid with a distinct null. Try to find an older (late 1990's) Decibel Products catalog. Much good information is stored in these old books. The second antenna you describe sounds like a DB-212. It mounts directly to the tower and want's to see tower leg above and below the antenna. This one produces an almost omni pattern with a slight cardoid null. Go to http://www.repeater-builder.com/antenna/ant-sys-index.html about 3/4 of the way dow the page you will find references to the DB-212 antenna and this link http://www.repeater-builder.com/db/pdfs/db-212-catalog-sheet-(andrew).pdf along with several others. Milt N3LTQ ----- Original Message ----- From: "Tim Ahrens" <[email protected]> To: <[email protected]> Sent: Wednesday, April 07, 2010 2:43 PM Subject: Re: [Repeater-Builder] DB-225 > Hi Chuck... > > Looks like I have two different versions of it. > > The one that is marked 225 has a square aluminum box > that the element pieces fit into. The driven side is farthest > away from the tower. It has a short (10") piece of pipe > attached to it that would fit into one of the standard > tower mount attachments. > > The second type - also marked DB products, but I can't > read the type, has the element pieces attached to a cast > aluminum piece. The driven side is closed to the tower, > an will also be about 7" from the tower. You could > attach the casting to a piece of pipe with clamps. > > Tim > > > ------------------------------------ > > > > Yahoo! Groups Links > > >
