Hi Dcflu7x, It's a DB products SP-1894. Can't get any info on it from anywhere.
Each of the 8 cans have the approx dimensions of 5" x 21". A single screw-type shaft in the center, and one SO-239 sticking out of the top of the can. No variable caps, or anything else on the cans. Each can has an RG-9 jumper between each 'T'. The male portion of the 'T' screws down into the can. The 4 cans on the 147.7 side are strictly 4 cans in series. The 4 cans on the 147.1 side also have an additional 'T' between cans, and from that dangles a short stub. The stubs actually pull up the high side of the notch. Without them, the cans exhibit high loss at 600khz above the notch. With them, the total loss is about 2 - 2.5dB. The duplexer was originally in the 166 range, then pulled down to the 154 range, which was what they were set for when I got them. Tuning: First I used the spectrum analyzer with tracking generator to move each notch on top of each other at the desired frequency. Next, I used my service monitor to generate a +10dBm signal which I fed through each set of 4 cans. On the opposite side, I hooked up the spectrum analyzer & tuned out the signal. It told me it was between -92 & -95 dB on each set of cans. I also put a 50 ohm load on the port that I was not testing. I think they are tweaked as good as they can be. Thanks, Tim W5FN --- In Repeater-Builder@yahoogroups.com, DCFluX <dcf...@...> wrote: > > Can you tell us more about the model of your duplexer? > > When you say notch is it: > > A. Flat pack mobile style notch only duplexer with a 3MHz minimum split. > B. Wacom BpBr cavites such as WP-639. > C. Motorola style notch only small cans. > > Also if you have a VHF circulator you can replace the tee between the > 2 sides of the duplexer and antenna for an additional 20dB of > isolation. > > > On Mon, Aug 10, 2009 at 9:07 AM, tahrens301<tahr...@...> wrote: > > Was just curious as to if folks have > > gotten Notch cavities to work ok with a 600khz > > split. Have 4 in Rx leg & 4 in TX leg. According > > to the analyzer, each bank has a >90dB notch. > > Double shielded cable throughout (RG-9). > > > > Just about pulled all my hair out over the last > > couple of weeks, and still have desense issues. > > Even tried another repeater, just to see if it > > was still there, & yep it is. (was actually a > > bit worse than the Quantar, but it uses cheesy > > cables for RX (TKR-720)). > > > > Did find something interesting inside the Quantar > > tho, the RX cable that screws into the RX filter > > housing had a problem. They use a crimped Mini-UHF, > > and the section that got crimped actually rotated > > freely around the piece that has the center conductor > > in it. Nice rotatable cable, but don't think that > > it was intended to do that! Soldered the two together. > > > > Thanks, > > > > Tim W5FN > > > > > > > > ------------------------------------ > > > > > > > > Yahoo! Groups Links > > > > > > > > >
