[Repeater-Builder] Re: MSR2000 PA out - again...
N9WYS [EMAIL PROTECTED] wrote: I have an MSR2000 on 444.550 for the local ham club / county EMA. The PA (a 110W model) is out again. We just had this repaired by the local Motorola shop, with whom we've had very good results from in the past. We're running the PA at about 80W, Not good, 60 watts max for typical repeater operation is about as far as I'd push it. You probably would not have noticed the repeater doing 40 to 60 watts vs 80. so I'm thinking we didn't burn it up, but I can't help but wonder if there is anything inherently wrong with the MSR2000 PA for UHF. There is, do you have an A or B version (model number suffix at the end)? This is the third time the PA has failed in this particular machine in about a 2-year time frame. You've got more than a PA problem. Possible high reflected power or lock to talk users. Do you have a circulator following the transmitter? (This was a repeater originally tuned for 460 MHZ, and brought down to the ham band.) And how was that done..? This particular machine has been a pain in the @$% - RX sensitivity isn't what it should be, What is it..? You might have some lightning damage in the receiver front end. One of the Canadian guys mentioned this problem a month or two back. PA keeps going out, etc. Seems like we're up at the site every couple of months do make some sort of repair on it. I'm wondering if we should just cut our losses and get another machine, or should I keep plugging away at this repeater? If we do decide to chuck it, how much can I expect to spend to get a comparable replacement - we use this machine during severe weather season for forwarding reports to the NWS, and it's open other times. We want to add remote RX sites (you've probably seen my inquiries about those in the past) but I don't want to start adding remote RX sites until I get the main repeater working reliably. I'm open to suggestions... Thanks, Mark - N9WYS I can't tell you what is best for your needs, but the PA issue is probably bigger than just that one part (the power amplifier). A circulator and a fan would be a godsend if you must run the 80 power level in the stock PA. You can repair it again, buy an $1100.00 drop in replacement from TPL or sub something else in. I've done all three, now I'm making my own predriver units for larger trailing PA's. All things considered, a working MSR is a good unit. cheers skipp skipp025 at yahoo.com www.radiowrench.com 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/
RE: [Repeater-Builder] Re: MSR2000 PA out - again...
Good question, but it added an extra .12 desense when we put it in... It's a TP-3200. -Original Message- From: Jim B. [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 07, 2004 1:48 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: MSR2000 PA out - again... N9WYS wrote: Hi, all... OK - I was hoping that 80W would be enough of a drop. Wasn't aware until these responses (yours and others) that the MSR PA was not rated for Continuous Duty. I'd have to check the model suffix - I don't remember right off hand. No - no circulator at this time. Seems SWR was low last we checked it, but I can't remember the specific reading - I think it was around 1.3:1, though. We followed the tuning procedure in the manual. We also used the Motorola test panel, so it was literally by the book... Last time we measured it (when we put the PA in the last time) RX sensitivity was about .5 µv straight into the receiver, .62 after adding the tone panel, and almost 1.0 after adding the duplexers. Why would the rx sensitivity change beacuse of the tone panel? That should have no effect at all... -- Jim Barbour WD8CHL 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/
Re: [Repeater-Builder] Re: MSR2000 PA out - again...
Sounds like some noise is getting in. Are all the leads shielded? How about the shields on the rx? I've put together a couple of TP-3200 rptrs, and none had that problem. -- Jim Barbour WD8CHL N9WYS wrote: Good question, but it added an extra .12 desense when we put it in... It's a TP-3200. -Original Message- From: Jim B. [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 07, 2004 1:48 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: MSR2000 PA out - again... N9WYS wrote: Hi, all... OK - I was hoping that 80W would be enough of a drop. Wasn't aware until these responses (yours and others) that the MSR PA was not rated for Continuous Duty. I'd have to check the model suffix - I don't remember right off hand. No - no circulator at this time. Seems SWR was low last we checked it, but I can't remember the specific reading - I think it was around 1.3:1, though. We followed the tuning procedure in the manual. We also used the Motorola test panel, so it was literally by the book... Last time we measured it (when we put the PA in the last time) RX sensitivity was about .5 µv straight into the receiver, .62 after adding the tone panel, and almost 1.0 after adding the duplexers. Why would the rx sensitivity change beacuse of the tone panel? That should have no effect at all... -- Jim Barbour WD8CHL 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/
[Repeater-Builder] Re: MSR2000 PA out - again...
Jim B. [EMAIL PROTECTED] wrote: Sounds like some noise is getting in. Are all the leads shielded? How about the shields on the rx? I've put together a couple of TP-3200 rptrs, and none had that problem. -- I have seen the TP3200 pannels generate some noise. Be sure to ask Communications Specialists for the latest E-Prom, they up dated the firmware and they work much better. Remember to use isolation resistors at the connection points on the MSR2000 TX tone and TX audio lines. The resistors help get rid of some conducted uP noise. 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/
