Good Morning/Afternoon Jim! Not sure about the Antenna, I know Randy's (HJC) is working great! Any type of double shielded coax/feedline anywhere in the system will cause problems. As the temp inside or outside changes it can cause the shield to rub together and make a lot of noise on the repeater. Even if it is used inside on the duplexers... I had mentioned to the person you are referring to that I may be able to find some 1/2" hardline but he thought it may be to weighted for what he is doing...
Corey N3FE On Mon, 31 Aug 2009 11:46:36 -0400, "Chuck Kelsey" wrote: > Sounds like maybe a bad antenna. Don't use the foil/braid cable anywhere in > > a repeater system. > > Chuck > WB2EDV > > > > ----- Original Message ----- > From: "ka2ajh" > To: > 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 >> >> >>
