Sounds like maybe a bad antenna. Don't use the foil/braid cable anywhere in a repeater system.
Chuck WB2EDV ----- Original Message ----- From: "ka2ajh" <ka2...@gmail.com> To: <Repeater-Builder@yahoogroups.com> Sent: Monday, August 31, 2009 9:33 AM Subject: [Repeater-Builder] Tram 1481 Dual Band UHF/VHF Antenna > Hi Guys, > We spent most of yesterday working on a UHF Mastr II Exec. Repeater, we > are using a TRAM 1481 Dual Band Antenna on. This is the high gain 8.3 dB > VHF/11.7 UHF. The system uses UHF Repeater, VHF Simplex, and IRLP. The > antenna works very poorly on UHF and much better on VHF. The SWR is about > 3-1 on both frequencies. The antenna is not DC Ground and there is no > shorted connectors. Lack of help prevented us from taking the antenna down > and apart at this time. We ran tests by putting the antenna on a portable > and working a fixed base and again the VHF pinned the meter and the UHF > was weak, only a couple of S units better than the portable rubber duck. > Has anyone had a similar problem. I understand that the antenna is a > compromise and not as good as a single band folded dipole for example, but > several of us have these and they work great except for this one. I am > thinking there are enough Tram 1481 out there and someone may have had the > same problem. > Also there has been many posts about the LMR400 used in repeater service. > It is my understanding that the foil type should NEVER be used between > duplexers, from the TX, RX to the Duplexers, but I am not sure about > between the duplexer and the antenna. Comments please! > My friend has the LM400 on the repeater mentioned above and I know it is > NOT the present problem as even on simplex the antenna performance on 440 > very poor. > > Thanks again an advance for your experiences and thoughts. > > 73 JIM KA2AJH > > > > ------------------------------------ > > > > Yahoo! Groups Links > > >
