Hi Again Tony; Sorry just re-read your e-mail and you mentioned the internal jumpers the answer was NO they are originals from Icom the external jumpers were all changed to new. Thanks Al VE3AJB
At 07:33 PM 27/11/2009, Radioman wrote: > > >Well >At least I'm not alone >I presume I have the same problem, and I didn't >relize I needed 90 plus isolation, so I'll swap >out the 4 pack for the 6 pack I have and check >things out, did u swap out the internal jumpers? > >Thanks for the reply and better news! > >73 - >Tony > >Sent from my iPod > >On Nov 27, 2009, at 5:19 PM, Allan Boyd ><<mailto:ve3...@vianet.ca>ve3...@vianet.ca> wrote: > >> >> >>Greetings Tony; >> >>Well after reading your e-mail let me know you >>are not alone with this problem with desense with >>the Icom D-Star 2 meter repeater. Our D-Star >>machine had the exact same problem when we first >>put it on the air. We had a 4 can duplexer with a >>high band pass cavity that was operating on a 60 >>watt analog repeater (GE Master II) with no >>problem at all. Once we put the D-star machine up >>on the same frequency same antenna and duplexer, >>cables etc the only thing that changed was the >>repeater was desense to the hilt. Tests showed we >>had about 85 db isolation. Like you we tried many >>things and troubleshooted everything else knowing >>that the duplexers were good. After much head >>scratching we finally learned through Icom rep >>that the D-Star Icom IR-RP2000V needs at least a >>minimum of 90db isolation and I say 90db at the >>very least. We finally changed out the 4 can to a >>6 can Sinclair res lock duplexer with a 100 db >>isolation and all I can say is WOW what a >>difference. The desense disappeared and the >>D-Star repeater now way out preformed the analog >>repeater we had up, it works amazingly because of >>the extra isolation. As you are aware the front >>ends of the Icom machine are not the best and >>leave a lot to be desired we learned the rule >>with this model repeater the more isolation you >>have the better you are. It worked fine for the >>analog system with the GE master II however once >>we went digital we needed the new set of cans up from 4 to six. >> >>Now I am not saying that this may be your problem >>but by your e-mail it certainly sounded like my >>complaint earlier in the year. Good luck. >>73 >>Al >>VE3AJB >>Trustee VE3RXR Stack >>Ontario Canada >> >>At 01:26 PM 27/11/2009, Radioman wrote: >> > >> > >> >well to start with the outside signal is garbled up until i switch to >> >low then the user clears up, when switching back to hi he gets garbled >> >up again and when the user unkeys i here 2 seconds of robotic noise, and >> >the robotic noise does not happen on low. >> > >> >i think that clear enough desense, with the tracking gen i have 86db of >> >isolation in the 4 pack cans >> >not perfect, but really not bad i also use a 10'' 3foot high band pass >> >cavity set to 1 db of loss and it gives me aprox >> >20db at 500khz window on my rx freqency >> > >> >honestly i don't think you could ask for any better then that, but the >> >desense sounds like i have no duplexer's >> >and I'm starting to point at the poor construction of this over sized >> >empty box and shielding mobile radios give you >> > >> >Tony >> >NN1D >> > >
