Close Call & Trunked Systems

[ScubaJungle]

I know that I've read that close call works with trunked systems, but has anyone had any luck with it?
So far, close-call has only worked for me with either conventional or single-frequency P25/other digital.
I was literally standing 10 feet from an officer and it did not register with close-call, nor as I walked towards/away (in case anyone says I was "too close").
I know, in theory, they are transmitting over a frequency just as any other conventional system does, just using a group of frequencies that are rotated around, but for whatever reason, it seems to not function right.

 

[KevinC]

I don't know where you are located, but if the system is using TDMA it won't trigger Close Call on the subscriber side.

 

[doctordialtone]

I know that I've read that close call works with trunked systems, but has anyone had any luck with it?

What model scanner?

Are you sure you have the proper bands turned on?



Plus what Kevin said.

 

[ScubaJungle]

Sorry, I always forget that. Bcd436hp, and yes, all bands except FM radio are on.
Happened again just now. Was shopping and an ambulance and fire truck were called. They were standing right near me, at one point I was within 10 feet of the firetruck, and they were transmitting, and nothing.
Yet, I was getting close call for a P25 single channel freq that was about 1000+ft away.

 

[jonwienke]

It won't detect if they are using Phase 2 TDMA.

 

[ScubaJungle]

It won't detect if they are using Phase 2 TDMA.

The unit I was next to was using EDACS conventional/analog.

 

[jonwienke]

How close? If you're 5 feet away from a mobile, the receiver might be overloading.

 

[ScubaJungle]

How close? If you're 5 feet away from a mobile, the receiver might be overloading.

I was from 10 through 1000 feet away. I drove up, passed them, walked past them, then did it again, and no matter how close/far I was, didnt get anything.
Doesnt seem to happen when I'm next to patrol cars that are also on EDACS conventional either. For the VA, which is P25 single-freq, I get it from quite a ways a way. Not sure why

 

[jonwienke]

Are you sure they were transmitting? Most radio traffic is during dispatch before they arrive, and then a brief "back in service" call when they leave, unless it's an active fire.

 

[ScubaJungle]

Are you sure they were transmitting? Most radio traffic is during dispatch before they arrive, and then a brief "back in service" call when they leave, unless it's an active fire.

Yes, they were talking into their radios. There's been many times I've been near/next to them but I cant assume they were transmitting just because I was next to them, so I didn't include those times.
However, it happened again today. Sheriff's deputies were sitting outside the supermarket and got a call; I saw them use their radios, probably to acknowledge, and nothing.
Within 2 minutes after they left, I got the supermarket security on close call, which was further from me than the deputies cars. The cars were about 30 feet away, and the security was inside the store which was at a minimum an extra 30-50 feet. So it seems the feature works fine with everything else, except EDACS. Not sure why, but it seems to just not work with EDACS, I wonder if anyone with a close-by EDACS system can chip in?

Either way, it's not much concern to me as overall, I love the BCD436HP, and I'm enjoying it regardless.

 

[wtp]

maybe too much "noise" on the sheriff's band ?
for close call to work the signal has to be at least a certain amount above the "floor".

 

[ScubaJungle]

maybe too much "noise" on the sheriff's band ?
for close call to work the signal has to be at least a certain amount above the "floor".

I suppose that would be the most likely answer, although Im not sure what would be interfering, and there's really only two 800mhz systems in the whole county.

I did notice, though, that close call wasnt picking up the store security either, until I switched digital threshold to manual and then the lowest mode possible.
Now that I think about it, I think it is a problem with signal sensitivity and digital threshold. I was getting a large bar on the 800mhz band, but I think that for whatever reason, the threshold is still too high. I cant lower it below 5, so I think it is just an issue with the sensitivity being too low.

 

[KevinC]

I suppose that would be the most likely answer, although Im not sure what would be interfering, and there's really only two 800mhz systems in the whole county.

I did notice, though, that close call wasnt picking up the store security either, until I switched digital threshold to manual and then the lowest mode possible.
Now that I think about it, I think it is a problem with signal sensitivity and digital threshold. I was getting a large bar on the 800mhz band, but I think that for whatever reason, the threshold is still too high. I cant lower it below 5, so I think it is just an issue with the sensitivity being too low.

You have to take into account ANYTHING in the receiving band. That would include Band 14 LTE and Sprint 800 LTE/CDMA sites.

 

[ScubaJungle]

You have to take into account ANYTHING in the receiving band. That would include Band 14 LTE and Sprint 800 LTE/CDMA sites.

That makes sense, I didnt know those were part of the band. Probably a combination then of noise and digital threshold a bit too high.

 

[jonwienke]

Same problem happens in t band with certain uhf TV stations.

 

[ScubaJungle]

Same problem happens in t band with certain uhf TV stations.

Makes sense, since the other close call bands seem to work just fine. Is there a way to manually lower the threshold past the limit set om the device, with software or something? I guess an LNA or filter would work, but that wouldnt really be ideal for a mobile application which is primarily what closecall is for.

 

[wtp]

try turning on attenuation. that cuts it to 1/100 of the original.
another thing i used to do was to set up a custom search of the band i think it is AND take the antenna out. then you don't need attenuation on.

 

[jonwienke]

Attenuation will not help. The close call chip triggers from a spike above the noise floor, and attenuation lowers the spike and noise floor equally.

 

[Ubbe]

I did notice, though, that close call wasnt picking up the store security either, until I switched digital threshold to manual and then the lowest mode possible.
Now that I think about it, I think it is a problem with signal sensitivity and digital threshold.

Could you try and experiment with that a bit more? The CloseCall function are a $5 frequency counter chip, it's named FX100 or something like that, and are sensing the RF signal after the pre-filters and should have nothing to do with the rest of the receiver, including digital decoder levels.

If you do see a relationsship between CloseCall performance and any decoder settings, then something is very wrong.

In the scanners menu for Search/Closecall it's only Freq Avoid and Broadcast Screen that should have any impact on CloseCall.
In the menu for CloseCall it's CC bands that needs to be set and then you use Close Call Only to let it continously check for hits without the rest of the scanners operations interfering with the process.

/Ubbe

 

[ScubaJungle]

Could you try and experiment with that a bit more? The CloseCall function are a $5 frequency counter chip, it's named FX100 or something like that, and are sensing the RF signal after the pre-filters and should have nothing to do with the rest of the receiver, including digital decoder levels.

If you do see a relationsship between CloseCall performance and any decoder settings, then something is very wrong.

In the scanners menu for Search/Closecall it's only Freq Avoid and Broadcast Screen that should have any impact on CloseCall.
In the menu for CloseCall it's CC bands that needs to be set and then you use Close Call Only to let it continously check for hits without the rest of the scanners operations interfering with the process.

/Ubbe

Definitely, and I would say it is totally possible that it wasnt really effected by lowering the threshold. I wasn't getting any signals, and then I lowered it, then got a signal soon after (so I assumed this was the reason, but could've been coincidence), but after that one close call, I never got another one. Also, I was in CC Only mode.
My close call feature constantly picks up signals from 200-205, which I believe are TV signals, if that makes a difference.