At 06:26 PM 4/1/05, you wrote: >Greetings all, > >I'm restoring a lightning-struck Kendecom Mark 4 to use as a back-up >repeater for our club. (Actually, I'm restoring two of them, but one is >already done and on line... but I digress.) > >I've got the second machine up and running and it's been doing well on my >bench for the past several days, but the one remaining problem I have is >with the audio board. The delay line (Reticon SAD4096) is bad, and will not >pass audio. > >I've jumpered around it so I now have a path for receiver and local audio to >pass to the transmitter, but unfortunately this causes a problem with the >autopatch. Without the delay line, the first short burst of DTMF audio >passes to the phone line and is JUST long enough to cause the autopatch to >misdial about 99% of the time. I know that this chip is pretty much >non-existent any more but I thought that perhaps someone out there might >just happen to have a spare they could part with. Short of that, perhaps >somebody has a relatively simple (and CHEAP) solution to the problem... >either a way to delay the audio just a fraction or to decrease the attack >time of the muting circuit so it cuts that short DTMF burst off. > >As I said, this is our 2nd backup machine and other than the autopatch it's >working fine, so I'm not willing to spend too much time or effort to get it >100% capable, but if it's something relatively painless, I'll give it a try. > > >As an aside, although I've been working professionally in electronics for >the past 24 years or so (and been a ham for nearly 30) I've only recently >become involved in repeater maintenance. This group has been a godsend and >I appreciate all who have offered their advice and assistance. Through the >suggestions I've received here, I was finally able to isolate an >intermittent problem with our primary receiver to a faulty receiver (of >course, it helps when the darn thing actually breaks when you're standing in >front of it at the repeater site too!) and it's now on its way back to ACS >for a FREE out-of-warranty repair. (Another BIG thanks to Gary at ACS for >going out of his way to be helpful!) > >Thankfully too, the Mark 4 is well documented and very easy to repair. I >really expected a mess when I opened them up, knowing that they had taken a >good jolt via the phone line, but the repairs have been very easy and the >parts (except for the darned delay line!) have been easy to come by. > >Thanks it advance to all & 73, > >Mike >WM4B >Kathleen, GA
Go to www.repeater-builder.com, then to the S-Com page. Look at the later DADM board doc file (it's a PDF). I'm 99% sure it's a drop-in replacement. It requires +10 to +15v of well-filtered DC at about 25ma, plus audio in and out. There is an extra pin that mutes the audio. That pin can optionally be wired to the RX COS output and can be dip-switch selected to be active-low (less than 1vDC) or active-high (over 3vDC). A while back S-Com sold the design and rights to Brian Martens KA9PMM at ICS. Their board is identical except for the name that is silkscreened onto it (basically, why screw with success?). See <http://www.ics-ctrl.com> and click on the "DADM" link on the left. Yes, it's about $70, but it's a proven product, needs no development time, and what is your time and energy worth? Mike WA6ILQ 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/
