Cellwave (Phelps Dodge) used this technique in making there low band VHF antenna adjustable. The PD320 (2 bay PD322, 4 bay PD324) had an element at this same position that adjusted the frequency of the antenna. You can see one here:
http://www.dapcom.com/images/rfdswa/Six_Meter_Antwebpg.jpg The upper and lower support arm to the tower are insulated, creating the typical loop antenna, except it's rectangular, rather than curved. This picture is of a single PD320 (although it's mounted upside down), with the extra element fully extended, which made it resonant at it's lowest frequency. To have the antenna set for it's highest frequency, you simply slid the element all the way inside the loop. I have one of these antennas on the side of my tower now, and use it for 6M. ----- Original Message ----- From: "Derek B. McIntyre" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Monday, January 12, 2004 7:32 PM Subject: [Repeater-Builder] Adding "whiskers" to a DB-224? > I have heard that adding whiskers to a DB-224 element (150-160 MHz) > is a good way to bring the antenna closer to resonance in the 2-meter > ham band. I have done this and it seems to work well. Has anyone > else tried this method and been successful, and seen any gain > increases? Any down-falls or pattern distortions with this method? > > See more details and pictures: > > http://www.w4dex.com/modify.htm > > Thanks for all responses on the "identify this antenna" message. > This group has been very helpful many topics. > > Derek KC4FWC Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
