BCD436HP: Missing transmission frustration

AxelsHumanDad

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Aug 30, 2006
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KAIG, The potato fields of Wisconsin
While sitting side by side with my 996T, my 436HP will all too often miss short transmissions or clip the beginning of transmissions.
I have both scanners holding on my local PD = Langlade County, WI 154.875.
As an example the call series may be:
"Langlade 436"
"436"
"436 can you 10-21?"
"10-4"
The 996T picks up everything without issue, every time.
No matter what tweaks I've tried the 436HP will miss the short replies, without even showing a signal strength display. On longer replies the beginning of the transmission is often clipped off. I'm about 10 blocks from the safety building so signal strength isn't an issue, both meter displays show a full graph.
Other than setting the P25 level to manual with a little adjustment, everything else is default in the 996T.
For the 436HP I currently have the system digital threshold mode manual and tweaked at 11, the hold time at 1 second, delay at 3 seconds, digital wait time is 200ms, digital AGC is on.
Changing the digital wait time to 0, 200, 400 has no effect. I have System, Department, and Channel all holding. Priority is off since both scanners are holding. Modulation type is NFM and Audio Option is NAC 8EE.
Swapping both scanners between the attached antenna and my outside antenna makes no difference. I haven't really noticed if it happens to other counties, but I don't think it is noticeable. It isn't every single time, but it is definitely much more often than not.
It's annoying and frustrating. It's holding me back from buying a 536 for concerns I'd have the same issue. I found a few other threads describing similar issues, but those suggestions did not work for me. I've had the 436 for about a year but I can't seem to resolve this problem. I mainly use ProScan to load the scanner, but using Sentinal doesn't make any difference.
I turn to the group here for other suggestions I might try.

Thanks.
 

jonwienke

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Digital wait time is your problem. If cuts off that much of every transmission to decide if a transmission is digital or analog. Set it to 0, and program the correct digital type and CC/RAN/NAC.
 

jonwienke

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Put the P25 threshold setting back to auto. The only time manual is (somewhat) helpful is when trying to receive simulcast, and even then, it's not all that useful to set manually.

Also, holding on a system doesn't stop the scanner from scanning multiple sites within a system, which take about a second per site. Hold on the site (Func, then DEPT).
 

Ubbe

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Digital Waiting Time are only used by the scanner if you have the Audio Type set to All. If it's set to Analog or Digital then that timer isn't in use.

The hold time will always be 1,5sec as a minimum so 1sec or 2sec are almost the same. You'll have to go 3sec to make a difference. It only uses hold if there's a carrier received from the site. If not it just scans past the site in a few milliseconds.

As you signal strenght indicator doesn't show anything when you miss the initial conversation it means that you are not receiving a signal and no settings, exeptc SQ level, will have any effect. If you are scanning several sites it should at least show a signal strenght from another site, even if that site doesn't transmit that TG call.

The 996 series are probably the best receiver Uniden have made and will receive better than a BCD436. But when you do receiver the call with the 436 it seems to work as it should so it shouldn't be a sensitivity issue.

The scanner are doing something else, perhaps scanning a lot of unneccesary frequencies in the system. Are you scanning all the voice channels in all the sites that you not even can receive? You only need to scan the control channel and perhaps the alternate control channel. It has to be something like 30-50 channels that are in the scan cycle to get that kind of delay when you hold on to that TG. Also check that no CloseCall or priority scan are in use.

/Ubbe
 

AxelsHumanDad

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This morning's update-

(in Sentinal):

1. >Scanner >Clear User Data
2. >Edit Favorites List >New Favorites List >created a list called Test
3. In the main USA database column, drilled down to my state/county/system/channel, left-click highlighted the sheriff dispatch channel, right-clicked >Append To Favorites List >Test
4. >Edit Favorites List >Test >County >set Digital Waiting Time to 0ms.
5. >Write To Scanner

Restarted scanner, display shows:
Langlade
Langlade County
Scanning...

Pressed the Channel/Mod button to hold. Display shows
Langlade
Langlade County
Sheriff Dispatch
154.8750MHz NFM NAC:8EEh

There is nothing except the sheriff dispatch loaded in the scanner. All priorities and alerts are off.
Still missing the short replies.
436 is connected to the outside antenna, 996T has the scanner mounted whip.
The 996T never misses a beat.
When I hear the short replies on the 996T I see full strength on the meter, yet the 436 meter doesn't show anything.
I have ProScan virtual displays up for both scanners so I can watch the log hit counters. The hit numbers for the 996 are much more than the 436. For whatever reason, the 436 just isn't responding to a lot of transmissions.

quick edit:
Many times when I hear "10-4" on the 996T I hear "4" on the 436.
The 436 isn't deaf, it's just late to react.
I never noticed missing/shortened transmissions from other departments when I had my full local database loaded, only from my local PD dispatch.
 

jonwienke

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I never noticed missing/shortened transmissions from other departments when I had my full local database loaded, only from my local PD dispatch.
You mentioned the transmitter is only a few blocks away. Have you tried turning on the attenuator to rule out overload?
 

scannerjunkie

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What firmware is your 436 currently at? current version is 1.26.00. i have the 436HP and I did notice audio clipping but it was not that often. After i did the recent firmware update my 436 sounded a lot better and audio clipping was no longer noticed.
 

Ubbe

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Still missing the short replies....Many times when I hear "10-4" on the 996T I hear "4" on the 436.
If it is the reply you are missing, then it sounds as if the 436 have begun to scan and are searching tru the other sites in the system. To always hear whole conversations until they end you usually have to increase the TG's dealy time so that the scanner stays long enough on the site to catch the reply.

Start by setting the delay for the TG's to 10 sec and if that works then go to 5 sec and decrease further if possible, if you still are able to catch the replies. For ID Search TG's, that you do not have programmed, it will still be the default 2 sec delay so push enter at each unknown TG to store them to the list and then read with Sentinel and paste in a longer delay time in one go to all TG's. I need to use a 7 sec delay, only possible with a Whistler scanner, to catch almost 95% of the replies. Using 5 sec in a Uniden scanner only catch 75% of replies with my systems. So I have to use a 10 sec TG delay on almost all systems I monitor with a Uniden scanner to not monitor two or several conversations mixing into each other so it's almost impossible to know what's going on.

/Ubbe
 

AxelsHumanDad

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KAIG, The potato fields of Wisconsin
If it is the reply you are missing, then it sounds as if the 436 have begun to scan and are searching tru the other sites in the system. To always hear whole conversations until they end you usually have to increase the TG's dealy time so that the scanner stays long enough on the site to catch the reply.

/Ubbe
There is nothing else programmed in the scanner other than the one frequency for my sheriff's department. There is nothing else to scan, and the scanner is holding on the freq.
 

Ubbe

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There is nothing else programmed in the scanner other than the one frequency for my sheriff's department. There is nothing else to scan, and the scanner is holding on the freq.
That's wierd if it holds on to that frequency but at some point not showing any signal strenght for it at, I.E not receiving that frequency.

If you turn down squelch to 0 it shouldn't matter if you only monitor that system. Then it HAS to stay on the frequency and show a signal strenght at all times.

Even better would be if you program that control channel, push Channel button to stop scan, enter the frequency and then push Enter to store it to Quick Save memory and in the next step it lets you edit the info so set it to analog only and save. Set the squelch to 0 and listen to the control channel data and see if you hear that data at all times and it doesn't suddenly dissapear and leave you with white noise and then the data returns.

/Ubbe
 

ChrisABQ

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Just throwing this out there, as this was an issue on the 436, EMI/RFI leakage in the area of the rear battery door. Have you done this mod? An owner mentions attenuation at 155 mhz as a result of no shielding causing lack of reception on a P25 control channel. I would be interested to know if you have done this?
 

AxelsHumanDad

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Location
KAIG, The potato fields of Wisconsin
That's wierd if it holds on to that frequency but at some point not showing any signal strenght for it at, I.E not receiving that frequency.

If you turn down squelch to 0 it shouldn't matter if you only monitor that system. Then it HAS to stay on the frequency and show a signal strenght at all times.

Even better would be if you program that control channel, push Channel button to stop scan, enter the frequency and then push Enter to store it to Quick Save memory and in the next step it lets you edit the info so set it to analog only and save. Set the squelch to 0 and listen to the control channel data and see if you hear that data at all times and it doesn't suddenly dissapear and leave you with white noise and then the data returns.

/Ubbe
It's a conventional system, no control channel.
 

AxelsHumanDad

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Joined
Aug 30, 2006
Messages
131
Location
KAIG, The potato fields of Wisconsin
Just throwing this out there, as this was an issue on the 436, EMI/RFI leakage in the area of the rear battery door. Have you done this mod? An owner mentions attenuation at 155 mhz as a result of no shielding causing lack of reception on a P25 control channel. I would be interested to know if you have done this?
First I've seen this one, I'll check it out, thanks.
 

AxelsHumanDad

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Joined
Aug 30, 2006
Messages
131
Location
KAIG, The potato fields of Wisconsin
Just throwing this out there, as this was an issue on the 436, EMI/RFI leakage in the area of the rear battery door. Have you done this mod? An owner mentions attenuation at 155 mhz as a result of no shielding causing lack of reception on a P25 control channel. I would be interested to know if you have done this?
From that discussion, I see this:
"The one time I do have demonstrable interference/attenuation is when the radio is plugged in to a USB power source while it's receiving. Similar to what you say with regards to the "hissing" - if I plug in the USB charging cable, a noticeable hiss/degradation in reception occurs, but only on a fairly narrow chunk of VHF in the 155 MHz range. All other bands appear unaffected. "

Mine is constantly connected to USB so I can use ProScan for virtual display. I'll try a fresh set of batteries without the USB cable to see if it helps.
 

jonwienke

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Just throwing this out there, as this was an issue on the 436, EMI/RFI leakage in the area of the rear battery door. Have you done this mod?
There's no need unless the scanner was made several years ago. Uniden made a hardware revision to the 436 several years ago that eliminated this issue.

RFI from the USB power supply is a possibility though.
 
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