Hi Milt, Thank you very much for your comets and suggestions, they are very apreciated. So as to save group bandwidth, Kindly please see my reply to Skipp's message, as it also deals with the antennas.
http://groups.yahoo.com/group/Repeater-Builder/message/53034 Alex --- In Repeater-Builder@yahoogroups.com, "Ellen Engle" <[EMAIL PROTECTED]> wrote: The DB-228 is about 41 feet long. Top antenna cannot be fully top mounted due to it's size so that means that about 20 ft is side mounted. That puts the bottom of the TX antenna at 70 ft. >TX is mounted from about mid-tower down.< OK I am interperating this to mean that the top of the bottom antenna is at say 50 ft, which puts the bottom at 10 ft. Total antenna seperation 20 ft. or less. Big problem. > > When you purchased the system, was it engineered for this spacing or did the antenna system come later? > > You need more isolation between the antennas. I would strongly suggest that you replace the antennas with DB-224's (20 ft long). Aim for a minimum of 60 ft of space between the bottom of the top antenna and the top of the side mount antenna. Since the description of the DB-228 indicates that it is made of 2 DB-224E's it may be possible to simply split one of the antennas apart and test that way. > > If you must stay with these high gain antennas then your TX combining and RX distribution systems need to be reengineered taking into account the short spacing (low isolation) between the TX and RX antennas. > > Ditch the RG-58 and the 9913 and use RG-214 or Superflex for jumpers. > > Verify the tuning of the cavities. Things change in shipment, especially in rough terrain. > > > Milt 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/
