Get rid of the LMR400 and replace it with some kind of hardline.
Vern KI4ONW From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of jstechnicalservice Sent: Thursday, May 08, 2008 9:08 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Best coax for short jumpers in repeater cabinet? > Thanks, Ron Here is more information on what we have. The HAAT is 122ft., we currently have a Maxrad MFB-1503 3db antenna and LMR400 coax. We are using a ST2 Midland at 110W and there is some type of older pre-amp installed with no tag, but has 6db hand written on it. Any suggestions for improvement will be appreciated but we do have a limited budget, especially with the impending rebanding. We want the high-band repeater in place for backup when this happens and also as our primary for the time being. > Jeff, > > To really give advice here what HAAT is your antenna. At 100 ft AGL 14 miles is about the expected range. Still depends on your terrain. > > As for feedline I think the LMR400 is a double shielded coax with 2 different shield materials. It has been found these generate noise on the tx side from the high RF. This would affect rcv. Probably good for rcv, but my standard is have nothing in a repeater that causes problems. > > I use either RG214 double shielded RG8 size and also 1/4" heliax. Both give good shielding and with short pieces little loss. Also RG142 which is a double shielded RG58 size cable often silver shield. Motorola and others use this inside their equipment. > > Never use double shielded cable with the 2 shields of different material like 9913 or some of the LMR stuff. Again the tx high RF will generate noise. > > 73, ron, n9ee/r > > > > > > > >From: jstechnicalservice <[EMAIL PROTECTED]> > >Date: 2008/05/08 Thu PM 12:30:30 CDT > >To: Repeater-Builder@yahoogroups.com <mailto:Repeater-Builder%40yahoogroups.com> > >Subject: [Repeater-Builder] Best coax for short jumpers in repeater cabinet? > > > > >I was hoping to get some opinions on the best coax to make jumpers for > >internal connections on a 152 Mhz public safety repeater. I'm currently > >using LMR400 and we can hit the repeater consistantly with a 5 watt > >handheld at 14 miles. The problem is we sometimes need around 15 to 16. > >I was hoping to improve performance as much as possible. Thanks > > > >Jeff Skaggs > >Concord-Greene FD > > > > > > > Ron Wright, N9EE > 727-376-6575 > MICRO COMPUTER CONCEPTS > Owner 146.64 repeater Tampa Bay, FL > No tone, all are welcome. >
