Re: [Repeater-Builder] Decibel repeater antenna question-unbalanced radiating loops

[Steve Grantham]

I think you will find that the feed point is 50-Ohms when feeding one of these single unbalanced dipole elements.  The harness is for making the multiple elements on the array look like one element to the transmission line.  Look at their (DB's) folded unipole antenna for low band.  It's a ground-plane antenna with a similar radiating element that's fed with 50-Ohm line.  The difference is that it's got radials on it instead of a mirrored counterpoise.  There may be other subtle differences, but...   Steve, aa5sg ----- Original Message ----- From: Paul Guello To: Repeater-Builder@yahoogroups.com Sent: Thursday, April 15, 2004 1:19 PM Subject: Re: [Repeater-Builder] Decibel repeater antenna question-unbalanced radiating loops There are not any baluns on these antennas.  If I remember right, they use 75 ohm coax on each bay (odd multiples of quarter wave length) and 35 ohm coax on the feed (again odd multiples) to match the impedance to 50 ohms.  This info was on the group a while back, somebody must still have it.   Paul, kb9wlc   Mathew Quaife <[EMAIL PROTECTED]> wrote: Would a close up pic of a DB304 work for your needs, or I have the DB420 there as well.   Mathew bradley glen <[EMAIL PROTECTED]> wrote: Hi I have been studying the db stacked array and the bayed array seems to use unbalanced dipoles as the radiators .I have tried to find a close up view of a single dipole so I can confirm my ideas. If anyone has some good tech info on these antennas I would appreciate the info. It would make sense to " by-pass " the need of baluns for each dipole -cost and balun loss????? Regards Brad ZS5WT Repeater Owner [EMAIL PROTECTED] __________________________________ Do you Yahoo!? Yahoo! Tax Center - File online by April 15th http://taxes.yahoo.com/filing.html 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/ Do you Yahoo!? Yahoo! Tax Center - File online by April 15th Do you Yahoo!? Yahoo! Tax Center - File online by April 15th 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 the Yahoo! Terms of Service.