Hi, I have called DB Products in the past, and if you get the right person on the phone, they will tell all. I suggest you try calling them on the phone and see what happens. The worst is you are out the long distance charge...
Jeff At 09:03 PM 1/30/2005, you wrote: >Paul; > > Memory serves me i think its a 1/2 wave length of coax the 462 > / f. in Mhz. and may be 50 ohm like RG 59/U I think . > >both must be uncoiled. and antennas on that config I believe is 1/2 Wave >apart. > >M. H. >----- Original Message ----- >From: <mailto:[EMAIL PROTECTED]>Paul Finch >To: <mailto:[email protected]>[email protected] >Sent: Friday, January 28, 2005 5:01 PM >Subject: RE: [Repeater-Builder] Decibel DB212-3 > >I have a couple of these antennas I am going to change to 6 meters. One >is going to be mounted on a 48 inch solid rod tower, the other will be on >a 14 inch tower. Does anyone have the specs on how they will work on the >different size towers? I am wanting a omni-directional pattern. > >Also, has anyone ever lengthened one to 10 meters? I cut it off three >times and it's still to short! Just kidding there. Where can I find the >info on the phasing harnesses? > >Paul >WB5IDM > > > >-----Original Message----- >From: Dave Baughn [mailto:[EMAIL PROTECTED] >Sent: Friday, January 28, 2005 10:36 AM >To: [email protected] >Subject: Re: [Repeater-Builder] Decibel DB212-3 > >According to the NAB Engineering Handbook, the gain of a stacked dipole >array peaks at just below one wavelength spacing (about 0.9 to 0.95). I >wouldn't go to 1 1/4, the gain will suffer some. If you try to maintain >0.9 wave (about 16' 8") and a tower member or something gets in the way, >just go a little wider to clear it. The effect will be minimal. The >aperture of the array is the main factor in determining the gain. One >wavelength works out to about 18' 7" and appears to be what DB is >suggesting and will work fine. > >My experience with broadcast antennas and repeaters confirms the above theory. > >Dave Baughn >Director of Engineering >The University of Alabama >Center for Public Television and Radio >Box 870150 >Tuscaloosa, Alabama 35487 >205.348.8622 cell 205-310-8798 >NEW EMAIL <mailto:[EMAIL PROTECTED]>[EMAIL PROTECTED] > > >>> [EMAIL PROTECTED] 01/28/05 08:37AM >>> >I'm making preparation to install a Decibel model DB212-3 antenna. The >antenna is a 3-element folded dipole and it has been modified for the ham >band. The antenna pattern is directional so I will be mounting the dipoles >on a single tower leg. The tower face is 5-feet, leg diameter is 5 inch. >What is the optimum center to center vertical spacing of the element for >53.47/52.47 Mhz ? The db spec sheet says anywhere between 3/4 on 1 1/4 >wavelength and suggest 19 ft. center to center at 50 Mhz. Anybody got any >experience with this ? As always thanks for your help. > >Jeff Corkren/W5PPB >Raymond, Mississippi > > > > > > > > > > > > > > > > > > > > > > > > > > >---------- >Yahoo! Groups Links > * To visit your group on the web, go to: > * > <http://groups.yahoo.com/group/Repeater-Builder/>http://groups.yahoo.com/group/Repeater-Builder/ > > > * > * To unsubscribe from this group, send an email to: > * > <mailto:[EMAIL PROTECTED]>[EMAIL PROTECTED] > > * > * Your use of Yahoo! Groups is subject to the > <http://docs.yahoo.com/info/terms/>Yahoo! Terms of Service. Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
