In that case use a single notch cavity to remove the 473 frequency in question.
Circulators can be used in conjunction with shorted stubs and cavities to create super narrow notch filters, but this may be more than you need. http://books.google.com/books?id=trJ6rhF0lU0C&pg=PA122&dq=circulator+notch+filter#v=onepage&q=circulator%20notch%20filter&f=false On Mon, Dec 7, 2009 at 5:21 PM, Ian Wells <kerin...@pacific.net.au> wrote: > > > How would a circulator or isolator work .The transmitt signal from the > data radio could pass through to the antenna and the rx signal could be > received from the antenna and The signal you wish to remove from the data > radio radio on receive could be notched to the dummy load . > The data radio radio frequencies are set for 507.025mhz rx 517.025mhz TX > and the frequency that is interfering is on 473.200mhz. > > Thank You ,Ian Wells > Kerinvale Comaudio, > 361 Camboon road, Biloela.4715 > Ph 0749922449 Mb 0409159932 > Hm 0749922574 Fx 0749922767 > www.kerinvalecomaudio.com.au > > *-------Original Message-------* > > *From:* DCFluX <dcf...@gmail.com> > *Date:* 8/12/2009 11:08:15 AM > *To:* Repeater-Builder@yahoogroups.com > *Subject:* Re: [Repeater-Builder] Sd174 uhf > > > > depends on the quality of the filter. I would try using the coax stub > routine with RG-58 as the coax, that should be fairly wide. But look at it > on a spectrum analyzer to be sure it will pass both signals. > > If not try building a 3-5 pole interdigital BPF. Those can tune 10MHz wide > easy. > > On Mon, Dec 7, 2009 at 4:57 PM, Ian Wells <kerin...@pacific.net.au> wrote: > > > Our TX and rx frequencies are 10 meg apart so a band pass filter may > have problems giving good signal on both or should I tune the filter in the > middle of the two frequencies > > > Thank You ,Ian Wells > Kerinvale Comaudio, > 361 Camboon road, Biloela.4715 > Ph 0749922449 Mb 0409159932 > Hm 0749922574 Fx 0749922767 > www.kerinvalecomaudio.com.au > > *-------Original Message-------* > > *From:* DCFluX <dcf...@gmail.com> > *Date:* 8/12/2009 10:53:00 AM > *To:* Repeater-Builder@yahoogroups.com > *Subject:* Re: [Repeater-Builder] Sd174 uhf > > > > The lack of a front end comes to mind. You basicly got there a hand held in > a pretty box with a DB-9. Try adding a bandpass filter, such as a bandpass > cavity, shorted coaxial stub or a interdigital bandpass filter. > > On Mon, Dec 7, 2009 at 3:42 PM, kerinvale <kerin...@pacific.net.au> wrote: > > > Hi guys .I have a SD 174 maxon data radio and it seems to not be able > filter other transmitters near by .The receiver opens up with squark noise > even when programmed with ctcss .can anyone suggest whats possibly the > problem is and possible fixes.I have one on site and it seems to be working > perfectly but I know of two that are the same carn't filter signals nearby > > > Thank You, > Ian Wells, > Kerinvale Comaudio, > 361 Camboon Road.Biloela.4715 > Ph 0749922449 or 0409159932 or 0749922574 > www.kerinvalecomaudio.com.au > > . > > > > > > > > > > > > > >
