put the TX into a dummy load and see if the RX gets better. If it does not try the rx into the preamp and to the rx on the repeater still dummy load on TX and see if any of that helps. let me know. also what is the reflected power on the unit?
thanks John ----- Original Message ----- From: "Alexander Tubonjic" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Friday, May 20, 2005 10:18 PM Subject: [Repeater-Builder] Poor Repeater RX > Hello, > Well here is one that cant be figured out locally, thought I would > throw it to the experts. My high school radio club has recently made a > few upgrades to our VHF repeater. We replaced the Ringo Ranger antenna > with a Comet GP-9 Antenna, replaced the 9913 coax with Andrews 1/2'' > Heliax, and put a Mirage Pream inline. The problem we are having is > mainly with the preamp (I think) > I will describe the setup and give all the specs first. The repeater > Rx and Tx is from a 110 Watt Motorola Mitrek power out from the Mitrek > is 50 watts. The power supply is an Astron RS-70M, Duplexer is a > Sinclair Q202G (yes, it is properly tuned and working as it should) > the antenna is rooftop on the schools theater building (the roof is > about 75 feet AGL and the antenna is on an 8' mast pipe) there are no > obstructions for at least 5 miles around. The preamp setup is as > follows, it is after the duplexers and before the reciever. We have > the preamp directly connected into the duplexer and a jumper going > from the preamp to the Rx bulkhead on the repeater cabinet. The preamp > has two settings, a higher gain and a lower gain setting, initially we > had it setup to the higher gain setting but I went up today and > switched over to lower gain and turned the power output to 30 watts. > The problem we have is the Rx is not what is should be. It is a tad > worse then when we were running the repeater at 15 watts without the > Preamp. I would really like to get the preamp to work like it should > in the repeater system, I just dont have any ideas on what to do next > to get better sensitivity on the machine. Any thoughts and ideas would > be appreciated. Thanks. > Alexander KG4OGN > > P.s, all jumpers are made with double shielded ridgid coax, so thats > not the cause of the problem. > > > > > > > > Yahoo! Groups Links > > > > > > > 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/
