Hi What you need is hybrid a ring isolator that uses one cavity and some specific phasing lines and that will notch out a close frequency as you discribed. They do have a little loss of around 2 dB's but are very sharp on the nulling out .If tweaked properly one can get about 45-60 db isolation.
They did appear in some of the old ham radio manuals. I am sure this should be good. http://www.repeater-builder.com/sinclair/w2euphybridringduplexer.pdf I have used these on two repeaters in the past and they look more complex than they are. We had semi-rigid which helped and omproved the isolation.Also stick to high quality connectors and NOT PL259 -these are at the bottom of the impedance stability list.N-Type are always good . Hope this helps you Regards Bradley Glen ZS5SWT http://mwmbers.harc.org.za/zs5swt --- Ian Wells <[EMAIL PROTECTED]> wrote: > These sites are 10-15kms from the nearest houses in > rual country .I have a > separate site to site licence that is still valid > that I don't use any more > and I am looking at utilizing it instead of the > diagram I sent through > before .I am having no worries with my remote sites > to the central hub site > I am only having problems with 2 sites that hav the > transmitt frequencies > 100-375khz away from the central hub signal which is > wipeing it .But if i > can use this other frequency that i have it will > them be upto 15meg away > from the sites transmitt frequency and shouldnt > affect it > > Thank You, > Ian Wells, > Kerinvale Comaudio, > www.kerinvalecomaudio.com.au > > -------Original Message------- > > From: AdamVazquez Kb2Jpd > Date: 03/28/06 23:38:39 > To: Repeater-Builder@yahoogroups.com; > Repeater-Builder@yahoogroups.com > Subject: Re: [Repeater-Builder] very close > frequencies seperation > > Usually, you use a backbone frequency on a different > band (in the US 220 Mhz > & up) or a dedicated dc controlled phone line so you > can have the desired > linking. > > It is difficult, but not impossible, to link on the > same band. Is that you > will thinking of implementing.? > > Adam Kb2Jpd > > -----Original Message----- > > From: "Ian Wells" <[EMAIL PROTECTED]> > Subj: [Repeater-Builder] very close frequencies > seperation > Date: Mon Mar 27, 2006 4:21 pm > Size: 2K > To: <Repeater-Builder@yahoogroups.com> > > v\:* {behavior:url (#default#vml);} v\:* { > BEHAVIOR: url (#default#vml) > } Hi guys .I am trying to receive 473.575mhz > from a 25 watt repeater > ,line of sight, 50kms away and and retransmitt it on > 473.200 at 25 watt on > another site.The transmitt antenna is a 6db vertical > ,9 meters above ground > and the rx antenna is a 6 db uhf beam 1-2 meter > above ground ,aimed at the > 473.575 site Is it possible to notch out frequencies > going into a receiver > that are275 or 375 khz off a uhfreceive signal or is > it going to be too > close to filter outthe TX . > > Thank You, > Ian Wells, > Kerinvale Comaudio, > www.kerinvalecomaudio.com.au > > > > > > > > > > YAHOO! GROUPS LINKS > > Visit your group "Repeater-Builder" on the web. > To unsubscribe from this group, send an email to: > [EMAIL PROTECTED] > Your use of Yahoo! Groups is subject to the Yahoo! > Terms of Service. > > --- Attachment imstp_wine_glass_en.gif--- > > > > > > > Yahoo! Groups Links > > > > > > > > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com 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/
