A 50 ohm terminator should suffice, you may want to tune the terminated side to notch the TX frequency.
On Mon, Dec 7, 2009 at 7:28 PM, Ian Wells <kerin...@pacific.net.au> wrote: > > > Yep its a mobile style 6 pack notch .would it be best with a 50 ohm > dummy load or 50 ohm terminator.I thought about tuning it with notch of > 473.200 on the side we want to use (between the sd174 and antenna) and notch > of 517.025 on the unused side (the side that goes to the dummy load) > > 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 12:59:08 PM > *To:* Repeater-Builder@yahoogroups.com > *Subject:* Re: [Repeater-Builder] Sd174 uhf > > > > dont know that number, but sounds like a mobile style 6 cavity notch > duplexer, try the other side if the insertion loss is too high going one > way, and the opposite side should have a 50 ohm load on it > > On Mon, Dec 7, 2009 at 6:01 PM, Ian Wells <kerin...@pacific.net.au> wrote: > > > Can one side of a 6mc450s diplexer be used as I have a few of them > laying around .The first test I tried worked well with a 6mc450s with no > interference but the 174 lost a lot of its TX power through it .from 3 watt > it reduced it down to .5 watt .I can say I didn't have a 50 ohm terminator > on the unused port which I should try next time and see how that's goes > > > 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 11:51:22 AM > *To:* Repeater-Builder@yahoogroups.com > *Subject:* Re: [Repeater-Builder] Sd174 uhf > > > > 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 > > . > > > > > > > > > > > > > > > > > > > > > >
