Batboard

Been working on an issue with a 4-channel Startsite system. The repeaters are MSF5000's. The system has been on the air for about 13 years, with very few problems...until now.

What's happening is the channel 1 repeater will drop all voice calls within a second or two. Using the test panel, I can see the "TX ACT1" light go out when the repeater drops. It's acting like it's not forwarding the correct "connect tone" to the controller, so the controller doesn't think there's a conversation going on, and it de-keys the repeater.

So, I use a 'scope to look at the discriminator audio pin right where it goes into the controller's RJ-45 jack...it appears to be fine...same audio level as the other 3 repeaters, waveforms look clean.

The repeater checks out perfectly fine on my service monitor in all respects. So, I try switching the controller cable from one of the other repeaters, the problem stays with the repeater. I've tried reprogramming and switching the repeater with one of the other repeaters in the system. Again, the problem still occurs with a different repeater in the #1 position. And now the former #1 repeater is working perfectly in the #2 slot.

It really appears to me that something's wrong with the Startsite controller. Most of the time, it is showing "MALF" for the channel 1 RIB (receiver interface board) when I view the repeaters with a system manager terminal. Occasionally, I can get it to show "ENABLED" if I disable then enable the channel with the terminal.

Oddly enough, it works perfectly fine as a control channel...so I know the channel requests from the field radios are getting through & the controller isn't having any issues with the data side of things.

I have our local Motorola rep sourcing a loaner Startsite controller to try out (system is under maintenance agreement with Motorola), but I thought I'd run it by you guys in the meantime.

Anybody run into a similar issue? Bernie maybe?

Oh, one other question...anybody know if I "protect" the other two control channel repeaters if the system will keep the #1 repeater as a control channel indefinitely? Or will it continue to hand off the control channel duty every day? If it kept the #1 repeater as control, that would be a good work-around for now.

Todd

The only way to stop channel 1 being assigned is new codeplug.
I assume you don't have any spare boards so
we will start with what is your connect tone?
If it not default 105.88 ( thats how the boards are manufactured) then it has been reworked to the new connect tone.
You may have a bad cap on the IRB. If you have the manual look at the connect tone filters and see if you find a dry joint.

If you protect channels all that means is that they will never be assigned a voice channel except as a last resort.
If you protect channel 2 then it will never get used except after 3 and 4 are used. Not really worth doing.
This is used more for makingsure there is always an interconnect or whatever securenet channel avialable.
Another easy option is check the codeplug and see if it is only programmed for 4 channels. Maybe there is a fifth.
If so move the repeater to channel 5 although have a good listen at first. You may not be licenced for it.
Anyway it either your IRB opr RIB gone bad.

Actually just pondered the idea of protection. I need to dig out an old manual but if you protect 2 and 3 then 1 will possibly remain control and 4 will get all the work.
So the next thing is protect 2,3 and 4 then they should all be last resorts meaning the load should be shared (I'm guessing a bit here)
The next problem becomes Channel 1 is now a full time CC
Thats fine for a Quantro/Quantar but an MSF might not cut it but I may be wrong as I've seen Purc 5000 paging (Msf paging txers) almost on continuous tx for at least a year without a failure.

Try the protection and see if it works.
If not is the site a remote location or in your shop.
If it is in your shop change the clock by 12 hours and manually switch it back at midday. Bit a bummer on weekends etc but it's an option.
If you have modem you can also write a command file to dial in and change the control channel back to one.

I'll look in my old manuals tommorrow and see what find.

Man I love my SmartZone Astro system. Throw Moscad and Full Vision on top and it's sit back and wait for an alarm. I even have a canopy link to my house for the remote stuff.

Thanks for the replies so far. I understand what protecting does, but the reason I was curious was when I had for example #2 protected, when I disabled #1, the control channel would jump to #3, as opposed to #2 as it normally would. So, protection is obviously also considered for control channels...I just don't know if it'll stop the "midnight rollover". Speaking of which, I already tried setting the time to a few minutes before "midnight" and waiting to see if the control channel switched. It didn't, so I don't know if it wants to wait until a full 24hours have passed since the control channel was assigned, or if there's a minimum timer involved, or what.

I doubt it's the IRB, as that's a shared resource between all the repeaters. I would think they would all have the problem if that were the case.

The only Startsite manual I have isn't very in-depth, so I don't know if there's a single connect tone filter inside, or if each channel has it's own. It isn't the default 105.88, but is 76.6...ordered that way from M years ago.

Unfortunately, there is no channel 5 blown into the codeplug. I wish it were that easy. It is a remote site (though only an hour or so away), with no dial-up capabilities.

I'm hoping the Startsite arrives today.

Todd

It really appears to me that something's wrong with the Startsite controller. Most of the time, it is showing "MALF" for the channel 1 RIB (receiver interface board) when I view the repeaters with a system manager terminal. Occasionally, I can get it to show "ENABLED" if I disable then enable the channel with the terminal.

Does the channel disable when the MALF occurs? Does your monitor panel show any RX activity when the channel is not active either on voice or control? Had these problems on a couple of my systems, ended up being the noise floor went so high from NextHell TX across the street that the carrier MALF timer would shut the channel down. I just disabled the timer (set to 0 if I remember right..) and it worked OK.

The channel dropping issue may be a bad RIB since you have moved repeaters around and the problem stays on the channel 1 slot. I've had that problem too when another tech installed a new channel and didn't get the connect tone programmed right in the station codeplug. You might also try swapping the controller to station cables on that channel although I don't think that's it. You may also want to look at the RSTAT line from the MSF to the controller and make sure the correct state is being sent to the controller. I don't have any of my books here, just remembering some of the crap I've done at 2-3AM on a Sunday. I may have a spare TCB for the MSF if you want to try that but again, if you moved repeaters around and the problem followed the slot in the controller, prolly not the station.

Bruce, doesn't the IRB only process the ISW for the control channels? Since that is high speed data, IRB should process the call and assign to a voice channel which then opens and stays assigned as long as there is correct connect tone and carrier.

As far as rollover, I ran 1 of my MSF stations for 2 years as a control channel, just make sure all 3 fans are running and the SWR is normal to the antenna or combiner and the power is set correctly. If you have a station with the external circulator and the load heats up, you will get a TX malf and it will shutdown.

Dave

Thanks Dave. Yep, tried switching cables already, no difference. I can't remember if I checked the RSTAT line or not...but switching cables & repeaters would seem to eliminate that anyway.

I thought of interference causing the MALF, but it does it even with a dummy load on the RX port of the MSF5000. Not picking anything up on the monitor either. No RX activity showing on the test panel when not receiving.

The channel does not disable when the MALF shows...in fact, it insists on making it the control channel. For example if the control channel is on repeater #3, and I enable repeater #1 and the RIB shows MALF, the control channel will immediately switch to repeater #1. If by chance it doesn't show MALF, it won't immediately make #1 the control channel. So, that's a little strange. And of course, once it automatically rolls over to another control channel, #1 becomes a voice channel & the problem occurs. If it would take it out of the loop, it would be a lot better.

Looks like the controller won't be here until Monday...customs clearance & all that stuff.

I'm going to dig my manuals out of the box in the garage and see if I can glean some more info.... I think when you get the other controller take one of the RIB's and stuff it into your controller, I think the problem will go away. It's sticking in my mind that it will be something tied to the RSTAT line on the RIB since you get the MALF and it disables a voice channel but it will assume the control channel duty fine.

Dave

The loaner Startsite controller arrived Monday. I popped it in yesterday morning (after swapping over the codeplug IC and setting the connect tone switches, of course). Everything came up perfectly and the system's been running great on all channels ever since. I'm going to hold on to the original controller until the end of the week while this one 'burns in'...come this Monday it's off to Motorola it goes.

Todd