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
