First a big thank you to Eric, David, Rodney, and Robert. It seems clear now that a circulator is not what I need. I plan to re-tune a pass cavity and put it on the TX side as suggested by Eric. David has warned of the possibility that this can cause a spur that might interfere with another system so I will try to have a spectrum analyzer look at the output.
Robert asked for some additional information. Here it is: RG-400 (new) in the cabinet, RG-214 (new) to the Heliax feed line. The RF environment is intense. I do not know what all is transmitting, but there are numerous antennas within 100 feet. The repeater is a Yaesu Musen FTR-5410. It drives a Mirage PA to about 90 watts. John Transue -----Original Message----- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of KD4PBC Sent: Wednesday, August 20, 2008 7:50 AM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] De-Sense and Circulator Question John, A couple questions. What are you using for interconnect cables, antenna, feedline ? Tell us something about the RF environment Hostile or not ? What type of radio are you using ? That Motorola duplexer is a very poor duplexer. With all the holes in them after a few years they may generate more noise than the suppress. All interconnecting cables need to be superflex or some other solid shielded cable. Any RG type cable the braided shield becomes illuminated and will cause noise and if there is a non linear junction can produce intermod. Send me the details and I will try and make some suggestions. Robert / KD4PBC __________ NOD32 3192 (20080616) Information __________ This message was checked by NOD32 antivirus system. http://www.eset.com
