Not very easily as I do not have any way to power it in my vehicle. I am line of site with the tower at the 911 center and can physically see all the antennas on the tower. That's why I know this is probably not a poor signal issue. I am going to continue to tinker with the those P25 settings and see how that goes. I've never had one of these scanners give me this much trouble!
BCD996XT Finding Cntrl Chan
- Thread starter jovitt
- Start date
-
- Tags
- 996xt control channel
- Status
tvengr
Well Known Member
All you need is the cigarette lighter plug cable that comes with the scanner.
The unit was given to me with only the ac wall adapter. I still don't think getting closer to the tower is going to help anything being as I can see the tower if I look out the window. I think it is a matter of adjusting those P25 settings until it cooperates. I will be tinkering with it for another hour tonight.
tvengr
Well Known Member
If the site antenna is that close, have you tried removing the scanner antenna and replacing it with a paper clip or short piece of wire?
It's important to understand that only one control channel is active at a time for each site. "Alternate" does not mean "also active in addition to" in this case; it means that if the system has an issue with the primary (active) control channel, it can switch to another frequency at the site which is also designated as control-capable.
In other words, the scanner must be correctly programmed to decode the active control channel, and will display DAT when it gets a lock on it. Forcing it to tune to one of the "alternate" control channels, which will be carrying voice or data when not functioning as the active control channel, is not going to work.
So upon breaking out an xts2500 and putting in every frequency from the 911 site, I discovered 2 frequencies actively transmitting as control frequencies. 460.5000 and 453.1500. I've set the site in the scanner to 453.1500 and tinkered with the p25 settings. It is now staying on the control channel, but not catching any conversations. I'm unsure where to go from here.
460.500 is the Onondaga Simulcast primary control channel; 453.150 is a voice/data channel, not control. I'm not sure exactly what you're parked on with 453.150, but it would help if you told us what the scanner is displaying.
If it's parked on an active control channel, it will display DAT. If it's parked on a channel transmitting data (non-control channel), it will display LNK. If it's parked on an active voice channel, it will display P25.
If it's parked on an active control channel, it will display DAT. If it's parked on a channel transmitting data (non-control channel), it will display LNK. If it's parked on an active voice channel, it will display P25.
The scanner is displaying DAT with 453.1500. This is starting to look more like some sort of interference/bleeding problem. I grabbed my SDR and listened to 453.1500 and it is dead as a door nail, yet it sounds like a P25 control channel on my XTS. 460.5000 is active and coming in great on the SDR with a rubber duck as well as the XTS. I still cannot get the scanner to lock on to the real control channel despite adjustments. I am going to try again tomorrow. I'm thinking of eliminating the scanner and just tapping the stations base radio for house alert audio as this scanner is more trouble than it is worth currently.
Plot twist...453.150 is also the Lewis County P25 system's primary control channel. It would not surprise me at all if you're picking that up, especially with a rooftop antenna.
I would suggest trying to identify the system that you're receiving on 453.150. You should be able to get the 996XT or SDS to display a System ID by parking on the control channel, possibly in Control Channel Only search mode on the 996XT. The Lewis County SysID is 70D with a matching NAC, while Onondaga's cell is 2AE with a NAC of 2A0.
I'd also remove all frequencies from the Onondaga programming in the scanner that are not flagged as control channels in the database, as the scanner does not require the voice channels in order to properly track the system. Program only the following four frequencies in this order, and make sure that 453.150 is not in the list of site frequencies to avoid it finding Lewis County's control channel.
460.500
460.4375
460.425
460.3625
I would suggest trying to identify the system that you're receiving on 453.150. You should be able to get the 996XT or SDS to display a System ID by parking on the control channel, possibly in Control Channel Only search mode on the 996XT. The Lewis County SysID is 70D with a matching NAC, while Onondaga's cell is 2AE with a NAC of 2A0.
I'd also remove all frequencies from the Onondaga programming in the scanner that are not flagged as control channels in the database, as the scanner does not require the voice channels in order to properly track the system. Program only the following four frequencies in this order, and make sure that 453.150 is not in the list of site frequencies to avoid it finding Lewis County's control channel.
460.500
460.4375
460.425
460.3625
Last edited:
Double plot twist, this morning I no longer hear anything on 453.1500. The portable that was picking some P25 noise up now doesn't pick up anything. The scanner plugged into the roof antenna also now has nothing on 453.1500. I have reprogrammed the site on the scanner to only have the control 460.5000. I got it to lock on only for about 5 seconds then it lost it again. It's back to just searching for the control channel despite trying every P25 adjustment. When I just turn the knob until it says 460.5000 and turn the scanner volume up, it doesn't sound like P25, more like just pure static. If I tune to the control channel on a portable, it sounds like a crisp P25 control channel. I have plugged my SDR into the roof antenna and used SDRTrunk to listen to the system and it is decoding just fine and I was picking up every transmission. I am still leaning towards a faulty scanner here. Even used a rubber duck on the SDR and it decodes perfectly as well.
Sounds like conditions were just right yesterday to pick up the Lewis control channel on 453.150, and have now faded.
Are you able to pick up anything else with the scanner? NOAA weather radio? Some active local VHF/UHF frequencies? Any other CNYICC sites?
Are you able to pick up anything else with the scanner? NOAA weather radio? Some active local VHF/UHF frequencies? Any other CNYICC sites?
Yup. Tested the county fire uhf rebroadcast as well as NOAA. Everything came in crisp and sounding good.
tvengr
Well Known Member
It looks like all of the frequencies on Lewis Co system are listed as control channel or alternates. They may have changed the control channel to another frequency and that is why you no longer hear the data on 453.150.
Sorry to bump this thread after a few months, I have tried some other things since my last time messing with this scanner. I have downgraded the firmware to 1.06 with no luck. I have messed with every single setting I could possibly mess with (I think). I have also put all the frequencies in the system into a conventional group and scanned through them. Even in line of sight with the tower at the 911 center, it is garbled and some conversations are cut off. It does decode the P25, but poorly. Is there a possibility this is a hardware issue here? Is there something that normally fails on these units? I'm really pulling my hair out on this issue.
I'm beginning to think you may have a simulcast distortion issue. Your scanner is receiving signals from multiple sites and is having trouble decoding them because they may be out of sync. Sort of like several people near you talking at once and you can't make anything out.
I know you've said you can't take your scanner closer to a site, but that's the only way I know of to confirm or refute a simulcast distortion problem.
If I remember correctly, you said you have a 396XT, which is an older line of scanners. They are not very good about decoding simulcast when you are between sites.
I know you've said you can't take your scanner closer to a site, but that's the only way I know of to confirm or refute a simulcast distortion problem.
If I remember correctly, you said you have a 396XT, which is an older line of scanners. They are not very good about decoding simulcast when you are between sites.
It is a BCD996XT. There shouldn't be too much simulcast distortion as I am line of sight with the 911 center which is one of the sites. I'm not in the middle of 2 sites so I wouldn't think simulcast distortion would be an issue, but I am not totally sure. The site at the 911 center has 460.500 which is the control, I listened to it on a portable and it sounds exactly how a P25 control channel should sound. I am thinking about tossing this thing or opening it up and checking for bad components.
doctordialtone
Member
Since you don't want to take good advice, I would just toss it.
What advice haven't I taken? I've done everything short of climb up the tower with the scanner in my hand...
tvengr
Well Known Member
Turn the P25 LP filter off. If you do not hear a 4 khz tone, leave it off. Using the filter ties up CPU time and can degrade P25 decoding. Can you attach the ARC-XT programming file so we can look at it?
doctordialtone
Member
- Status
Similar threads
SDS100/SDS200:
SDS-100 updated firmware control channel issues
