Paul, I talked with my friend about the DB224. He said as you did. When you get it you have to tighten the hardware. Some was more than finger loose. This is for all antennas, but more for DB Products.
He has used the Scotchkote. He likes it, but noted lasted only 3-5 years. He has remove antennas it was used on and at places where he had put black tape then coated it with the Scotchkote the tape was there, but the Scotchkote was gone especially on the side of the sun exposure. He did not know what the MEK was. Another problem he and I also have seen with the DB224 is where the high side of the coax connects to the folded dipoles. There is a small think fiberglass tubing to secure the loop ends together. We have noted on antennas that have been up for a while this piece is either gone or badly damaged. Mainly a structure component. I'm giving myself about a week to think on the DB224 or Station Master. I like both, but lean toward the Station Master. 73, ron, n9ee/r >From: Paul Finch <[EMAIL PROTECTED]> >Date: 2008/05/01 Thu AM 10:44:37 CDT >To: Repeater-Builder@yahoogroups.com >Subject: RE: [Repeater-Builder] antenna question >Ron, > >I am a big proponent of the DB line of antennas but I also add that they >must be set up correctly before they are installed, especially in a high >humidity/salt air environment like you are talking about. The following is >what I learned form the two engineers that developed the DB line of folded >dipole antennas decades ago. > >I have posted this several times on R/B and will do it again. When you get >a brand new antenna from DB you must take all the nuts off where the coax >connects to the dipoles and tighten the screws and nuts through the dipole, >you will find many are finger tight. Once these screws and nuts are tight >then put the coax terminal back on the dipole. > >The second part of making a new DB folded dipole antenna last is sealing >every nook and cranny of the antenna with 3M Scotchkote. I paint at least >two coats on every screwhead, coax end, nut, plastic molded junction and >anything that could be a point of bimetal corrosion or coax water leak. If >I could dip it in Scotchkote I would. Warning, don't get it on your skin, >you will wear it for several days. You can clean it up a little with MEK. >By the way, I did some research and MEK is not as bad of a carcinogen as >some people would lead you to believe. > >I have installed several DB 224 antennas in the Tampa area with this method >with few problems. While the fiberglass antennas have the radome they are >still vented to the salt air and you can't get in them to seal the potential >bimetal corrosion problems like you can the DB antennas. One other plus for >folded dipole antennas, the fiberglass antennas are much more prone to >become toothpicks with a lightning strike where a 224 will most likely >survive. > >Paul > > >-----Original Message----- >From: Repeater-Builder@yahoogroups.com >[mailto:[EMAIL PROTECTED] On Behalf Of Ron Wright >Sent: Thursday, May 01, 2008 9:39 AM >To: Repeater-Builder@yahoogroups.com >Subject: Re: [Repeater-Builder] antenna question > >hi all, > >I am about to replace a DB224 side mounted at 1175 ft above ground. The >antenna is close to the Gulf, 0.5 mi, and think the salt air got to it. It >has been up about 12 years and now has an SWR of 2:1. The coverage is very >noticeably less. > >I am thinking of a Super Station Master fiberglass enclosed antenna as a >replacement. The Celwave/RFS 220 is my thinking. > >Any thoughts about this from some who have experience with salt air. > >I like the DB224 and many locally use them. I like being able to skew the >pattern, but others locally have had similar salt air problems with VHF and >UHF exposed dipoles. I've also seen the Super Station Masters last decades >in harsh environments. > >73, ron, n9ee/r > > >Ron Wright, N9EE >727-376-6575 >MICRO COMPUTER CONCEPTS >Owner 146.64 repeater Tampa Bay, FL >No tone, all are welcome. > > > >------------------------------------ > > > >Yahoo! Groups Links > > > > >No virus found in this incoming message. >Checked by AVG. >Version: 7.5.524 / Virus Database: 269.23.7/1408 - Release Date: 4/30/2008 >6:10 PM > > >No virus found in this outgoing message. >Checked by AVG. >Version: 7.5.524 / Virus Database: 269.23.7/1408 - Release Date: 4/30/2008 >6:10 PM > > > >------------------------------------ > > > >Yahoo! Groups Links > > > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
