Nothing received until analyze mode entered & exited?

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N0BDW

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Hi folks,

Has anyone seen an issue where the 536HP will not receive anything from a system until you've gone into analyze mode and then exited it (FUNC+SYSTEM)?

I'm only monitoring one system and it is in ID Search mode. For some reason it doesn't pick up any transmissions on the system after a reboot until I go into analyze then back out.
 

RFI-EMI-GUY

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I made a video to show the problem I'm having (and prove I'm not crazy). Again I'm having this on two separate BCD536HP units, and my friend hfd26 is having the problem on a BCD436HP.

https://www.youtube.com/watch?v=lC4OXVB-bU8

I Have a brand new (actually built a year ago) 536HP that Amazon delivered and am unable to receive anything on the Seminole County FL system unless I am in the Discovery mode. Being a "neophyte" I am suspecting that either the control channel assignments are wrong or the P25 threshold is off having some difficulty with LSM.. Any thoughts?
 

N0BDW

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I Have a brand new (actually built a year ago) 536HP that Amazon delivered and am unable to receive anything on the Seminole County FL system unless I am in the Discovery mode. Being a "neophyte" I am suspecting that either the control channel assignments are wrong or the P25 threshold is off having some difficulty with LSM.. Any thoughts?

Do you have ID Search turned on?

Have you checked your service types to see which ones are enabled?

Have you tried entering and exiting Analyze as I did in my video, and does that work?



I still have no answer as to why I have to do that in order to listen to this system. Does Uniden have an official technical support that is capable of addressing questions like that or is this forum, with the hope of a reply from Upman, the best bet?
 

RFI-EMI-GUY

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After I exited Discovery mode, all seems well with the radio receiving that system. It works when power is cycled, and even after a reset of user preferences. So I have no idea what was going on. I do realize now that this is unlike any radio I have ever programmed, in that everything in the search circle is turned on. I have made a favorites list and can listen to the systems and departments desired. I am struggling with conventional favorites as the GMRS is coming up with "nothing to scan". So my struggle and education continue!
 

RFI-EMI-GUY

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Service types may be why GMRS and FRS are not scanning. This is a different kind of radio. I will try that.
 

GTR8000

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I wonder if the scanner is not loading the bandplan correctly until you put it into analyze mode.

P25 systems broadcast the band plan over the control channel. The scanner is supposed to fill this in automatically. Without the proper band plan, the scanner will not know which voice frequencies to tune to.

Since this is a VHF TDMA system with nine band plan entries, it would be critical that the scanner process this information correctly, otherwise you'll hear nothing but silence.
 

N0BDW

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I wonder if the scanner is not loading the bandplan correctly until you put it into analyze mode.

P25 systems broadcast the band plan over the control channel. The scanner is supposed to fill this in automatically. Without the proper band plan, the scanner will not know which voice frequencies to tune to.

Since this is a VHF TDMA system with nine band plan entries, it would be critical that the scanner process this information correctly, otherwise you'll hear nothing but silence.

Interesting. How could I test that theory? Do you know what I should fill in for the band plan in Sentinel?
 

GTR8000

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Hi Ben,

Start fresh after a power cycle. Let it scan for a bit just to give it a fair chance at acquiring the band plan.

Now, take a look at the band plan entries:

Menu > Manage Favorites > FAVORITE LIST > Review/Edit System > Livingston County P25 > Edit Site > Simulcast > Edit Band Plan

Look to see if the entries are populated. If yes, there is something else going on. If no, then for some reason the scanner is not correctly processing the band plan during normal scanning operation.

Your band plan for that system should be as follows:

0:136.00000/6.2500
1:-/-
2:-/-
3:-/-
4:-/-
5:-/-
6:151.63750/2.500
7:153.98750/2.500
8:154.36250/2.500
9:154.81500/2.500
A:151.63750/2.500
B:153.98750/2.500
C:154.36250/2.500
D:154.81500/2.500
 

GTR8000

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It's also worth noting that a good, solid lock on a P25 control channel in Analyze mode should only display DAT, and the NAC should remain steady as well.

In viewing your video, I see that the scanner keeps flipping between DAT and LNK, and the NAC keeps fading in and out. That should not be happening.

Additionally, when in normal scan mode with no talkgroup activity, the only indicator you should see is a solid DAT. When the scanner tunes to a voice channel, DAT should disappear until the transmission is over and a TDMA system will display the voice channel slot (PT0 or PT1). You should not be seeing LNK during normal scan mode.

Any other behavior indicates that the scanner is struggling with the simulcast.


There is only so much you can do to mitigate simulcast multi-path issues with these scanners.

A Yagi helps, sure, but it can't completely eliminate receiving RF from other nearby subsites, it can only minimize reception of unwanted signals.

You're also not just dealing with the direct RF propagating out from each subsite, but you're also dealing with reflected signals bouncing off buildings and mountains from both the subsite you're trying to receive, as well as other subsites.
 

N0BDW

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Hi Ben,

Start fresh after a power cycle. Let it scan for a bit just to give it a fair chance at acquiring the band plan.

Now, take a look at the band plan entries:

Menu > Manage Favorites > FAVORITE LIST > Review/Edit System > Livingston County P25 > Edit Site > Simulcast > Edit Band Plan

Look to see if the entries are populated. If yes, there is something else going on. If no, then for some reason the scanner is not correctly processing the band plan during normal scanning operation.

Your band plan for that system should be as follows:

0:136.00000/6.2500
1:-/-
2:-/-
3:-/-
4:-/-
5:-/-
6:151.63750/2.500
7:153.98750/2.500
8:154.36250/2.500
9:154.81500/2.500
A:151.63750/2.500
B:153.98750/2.500
C:154.36250/2.500
D:154.81500/2.500

It was a good thought, but this does not seem to be a problem with the band plan:

https://youtu.be/P9cnCqGi-uM

Exactly what you've shared has now been programmed via Sentinel and is the same before and after an analyze, but the scanner still doesn't lock onto the control channel until an analyze has been done.
 

GTR8000

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Well, it was worth a shot I suppose.

I have a feeling that this is all simulcast multi-path related, unfortunately.

Since you have a Yagi on that scanner at the fire station, have you tried enabling attenuation for that system? I don't know that it would make a difference, but it certainly can't hurt to try.
 

GTR8000

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Bingo, my suspicion was correct.

The scanner is not correctly auto-populating the full band plan in normal scan mode. Instead, for whatever reason, it is requiring you to go into Analyze mode in order for it to correctly populate the full band plan.

What is most glaring is that you noted that it wasn't correctly populating band plan entries A through D (10-13), which is critical for this particular system because those are the TDMA entries, and of course all of the talkgroups on Livingston's system are strapped for TDMA operation.
 

N0BDW

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Even if the band plan is manually entered using Sentinel it seems the scanner ignores it until analyze mode is entered and exited.

Can we please get a fix in a firmware update, Upman?
 

N0BDW

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I left one of these all day today, just to see if with enough time sitting and spinning if it would do anything, and it still didn't pick up the A through D entries until I got home and entered analyze mode. Nothing was recorded all day though there was activity on the system.
 
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