OK, thanks Jeff. That could well be. I'm aware that higher gain figures on an omni antenna result in a narrower vertical beam width, so maybe the stations that aren't getting in as well as I'm expecting are "under" the optimal antenna beamwidth/pattern.
Or am I just trying to be too cerebral about all this? Mark - N9WYS -----Original Message----- From: Repeater-Builder@yahoogroups.com On Behalf Of Jeff Kincaid Sent: Saturday, June 07, 2008 11:47 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: antenna suggestions for 440mhz Maybe you're already hearing as well as you're going to at that site. A given user signal is only going to be so strong compared to the noise level no matter what you do. Jeff --- In Repeater-Builder@yahoogroups.com, "n9wys" <[EMAIL PROTECTED]> wrote: > > In fear of moving off topic... I'd like to ask how one can determine the > electrical downtilt of an antenna? > > I just put into service a RSF/Celwave Super StationmasterR Model 10017-6 > that is designed for 925-960 MHz on my 927.5250 repeater. The added gain > factor of the antenna (an additional 4dBd over what was previously in place > - a Decibel DB586-Y) does not seem to benefit the receive (at 902 MHz). I > gained what seems like a little extra receive range, but not equal to what I > seem to have gained in transmit coverage. > > This discussion thread leads me to wonder if maybe some electrical downtilt > may be affecting the receive frequency? Is this possible? Antennas are not > my strong point. ;-) > > Thanks, > Mark - N9WYS > > -----Original Message----- > From: Repeater-Builder@yahoogroups.com > [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] > Sent: Friday, June 06, 2008 11:19 PM > To: Repeater-Builder@yahoogroups.com > Subject: Re: [Repeater-Builder] Re: antenna suggestions for 440mhz > > At 6/6/2008 19:22, you wrote: > > >The series-fed types (usually fiberglass at these frequencies) *will* > >tilt their patterns when moving away from their design frequency. > > > >Laryn K8TVZ > > The good news is that the pattern tilts down when used at frequencies below > the design frequency. The big question is by how much. Would be easy to > calculate in NECWin if I could only get a good NEC model for the coaxial > colinear array. I'm not quite expert enough in NEC to figure out how to > create that model. > > Bob NO6B > ------------------------------------ Yahoo! Groups Links No virus found in this incoming message. Checked by AVG. Version: 8.0.100 / Virus Database: 270.0.0/1489 - Release Date: 6/7/2008 11:17 AM
