Ron and Eric, I emailed this out before, here goes again. I learned all I know about the DB antennas from two of the engineers that designed the antenna many years ago. My Boss at the time was a personnel friend of one and the other ended up at Wacom where I did a lot of business with him. I have a lot of respect for both.
First, when you get a DB folded dipole antenna, disconnect all connections at the dipoles and tighten everything and put it back together. After that, put as many coats as you can of Scotchkote from 3M on every connection, especially if dissimilar metals are present. Coat every knot, terminal and joint on the antenna with Scotchkote that you can. Coat the whole thing if you can. That keeps the salt from getting to those parts. Do this and the antenna will last much longer and outlive the fiberglass antennas every time. I was Director of Field Engineering for a nationwide paging company, we had a office in Tampa Florida and all we used were the DB-224 antennas. I threatened to fire anyone that put an antenna in the air without tightening the connections and sealing it first. Never had to fire anyone over that, they knew how important it was to me. We still had a few problems mainly from the first batch of Phelps Dog (Dodge aka Celwave aka RF Industries or whatever they call themselves now) antennas we put up. The difference between the folded dipole antenna and fiberglass radome antennas in lightning was not worth the chance in a emergency system. Hope this helps, Paul -----Original Message----- From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Eric Lemmon Sent: Saturday, September 01, 2007 9:45 AM To: [email protected] Subject: [Repeater-Builder] DB224 Survival in Florida Paul, Eleven years in a salt-air and lightning-prone environment is pretty darn good! I daresay the Super Stationmaster would not last that long. Fiberglass vertical antennas can be permanently damaged when struck by lightning, whereas the aluminum dipoles might shrug off such abuse. At least, that's been the experience at nearby Vandenberg AFB. It is not clear from your post if you have established beyond any doubt that it is the antenna causing your SWR problem. Have you determined that the feedline is not cracked or dented due to flexing, not worn through at some point, no water in the line, center pin(s) haven't pulled out due to elongation, no bullet holes, etc., etc.? 73, Eric Lemmon WB6FLY -----Original Message----- From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Ron Wright Sent: Saturday, September 01, 2007 7:12 AM To: [email protected] Subject: Re: RE: [Repeater-Builder] Wal Mart effect makes it to the Communications Hard (feed)-Line industry Paul, I have a DB224 at 1175 ft above ground 1/2 mile from the Gulf of Mexico here in FL. Put up in 1996 and it is having serious problems, 2:1 SWR on the ground. Think it is the salt air. The connections, on antenna and connectors, were coated and sealed before install. Other services with exposed dipoles have had the same problem here. We have same antennas about 5 miles from the Gulf that last for years although none past 20 years. Have seen about 5 of these replaced recently, most VHF. When I replace my DB224 I am going to a SuperStation Master fiber glass pole. It is obvious the exposed dipoles have a survival problem in this salt air. I know what you mean about the fiber poles and lightning due to the soldering connections. If top mounted would be reluctant, but have seen these last over 20 years and still had plenty of life in them in some harsh enviorments. I like the DB224 with it squeeing of the pattern, but exposed dipoles can have problems. Same with towers up north with ice falling off a tower. 73, ron, n9ee/r <unrelated text deleted> Yahoo! Groups Links No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.484 / Virus Database: 269.13.0/980 - Release Date: 8/30/2007 6:05 PM No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.484 / Virus Database: 269.13.2 - Release Date: 9/1/2007 12:00 AM No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.484 / Virus Database: 269.13.2 - Release Date: 9/1/2007 12:00 AM Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Repeater-Builder/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> 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/
