BCD536HP External Audio Very Weak

[SCPD]

Here ya go , new thread here --> http://forums.radioreference.com/un...536hp-speaker-output-problem-serial-mode.html

Wish I had seen this thread before the one quoted .....

First off: I too am able to get Alpha tags in Scanner cast, but I had to do two things. A check the 396.996 circle and change the format setting to "TGRP or CONV name" I crashed Scannercast using the other setting as SC didn't recognize the 3 line format.

Second: I have the same audio problems on the Rear Speaker out that you are describing. I tried a C-Media USB card, C-Media SiiG internal Card, Soundblaster Internal card and the PC's onboard audio (RealTek) and got the same LOW Audio, especially with Digital signals. Turning the radio up, the Mic up and selecting the AGC setting only made the digital sound over modulated but cleared up the analog some.

Now I am playing with some Mackie Mixers and Amplifiers to see if that might fix this annoying bug. And yes, my 996XT and other Uniden, GRE and Shack scanners do not have this problem. In the car I use a Motorola Amplified speaker which of course works like a champ. At home a non-amplified Motorola speaker does just fine. Its when it comes in contact with the computer that all hell breaks loose.

 

[an39511]

Several day ado I started the link http://forums.radioreference.com/uniden-scanners/283794-bcd536hp-audio-output-problems.html
For those of you having weak audio output when trying to connect the rear audio to your computer this link may help explain what is happening.

 

[markab]

Folks... Please be VERY careful when connecting the speaker out jack to anything other than a speaker. As Upman has pointed out in another post that jack is being driven by a BTL (bridge tied load) amp. If the shield is grounded you short out the amp and can do PERMANENT DAMAGE to it. Please read up on this first and know what you're doing so that you don't cook your amp. This is not a hardware flaw but simply a different design.

PS: If you cooked your amp as a result of incorrectly wiring its output I doubt it would be covered under warranty as it would be the result of user error.

 

[BigEvil]

Please be VERY careful when connecting the speaker out jack to anything other than a speaker. As Upman has pointed out in another post that jack is being driven by a BTL (bridge tied load) amp. If the shield is grounded you short out the amp and can do PERMANENT DAMAGE to it. Please read up on this first and know what you're doing so that you don't cook your amp. This is not a hardware flaw but simply a different design.

PS: If you cooked your amp as a result of incorrectly wiring its output I doubt it would be covered under warranty as it would be the result of user error.

So does that mean it is not safe to connect it from the speaker output to a soundcard input? If so, how does one connect these scanners to their computers for streaming?

 

[markab]

Hook up

So does that mean it is not safe to connect it from the speaker output to a soundcard input? If so, how does one connect these scanners to their computers for streaming?

I believe it can be done, just not the way many here are use to doing it. The following link may help to shed some light on it.

http://ncsradio.com/commercial/Data%...ied Load.pdf

I'm not an electrical engineer but it would seem that adding an audio isolation transformer may do the trick.
Hope this helps.

Mark

EDIT: Grrr. the link now doesn't seem to be working for me. If you google bridge tied link there is a lot of information that should help users wire things up correctly.

 

[markab]

I think this link will work. (fingers crossed).

http://ncsradio.com/commercial/Data Sheets/Connecting Radios with Bridge Tied Load.pdf

 

[SCPD]

I believe it can be done, just not the way many here are use to doing it. The following link may help to shed some light on it.

http://ncsradio.com/commercial/Data%...ied Load.pdf

I'm not an electrical engineer but it would seem that adding an audio isolation transformer may do the trick.
Hope this helps.

So basically in-lining a low power amplifier should do the trick?

 

[SCPD]

OK guys, Adding an amplifier inline works! I added a small CD Player which happen to have a line in that usually has my tab attached to it., then went Speaker Left out to Mic in on the PC and Wham!!! Much higher Audio levels.

Will leave this on the feed for the night and see what it sounds like. My Feed if you want to give it a listen.

THIS probably would do the trick for permanent long term use.

Thanks for all the help!

 

[WaveJam]

So this is all great info and I appreciate it. But... I too saw the warning from UPMAN regarding:

As Upman has pointed out in another post that jack is being driven by a BTL (bridge tied load) amp. If the shield is grounded you short out the amp and can do PERMANENT DAMAGE to it.

And in the same breath I saw:

This is not a hardware flaw but simply a different design.

Ok... If its a new design... Then... Those of us that are running feeds either risk damaging the units for the appropriate sound levels or we just do not use the 536HP with Alphatags on our feeds?

I'm hoping to hear of a "supported" work around for this issue. I'm not an electronics guy and I side-step any conversations that include the word "solder". Me + a soldering iron = imminent danger. ;-)

With this new audio design, what advantages does it offer over lets say the 996XT? The differences I see are this grounding issue and a more muffled audio which I see as disadvantages.

 

[NYRHKY94]

WaveJam:

I believe the permanent solution will be for us to run our feeds using the "headphone" jack once we receive our replacement units. The speaker out method for running feeds is not recommended by the RR staff even with the previous models (for feed sound quality purposes). The number #1 recommended method is to use the Line/REC jack, however we all know that has been removed on the new models....

 

[fenderblue]

I guess the amplified speaker that Scanner Master sells would be ok on a 536HP. It works great w/396xt in the mobile.

 

[WaveJam]

I believe the permanent solution will be for us to run our feeds using the "headphone" jack

Thanks. When I do that I get a hissing noise into the feed.

once we receive our replacement units.

Is there definitive word on this? I thought they were only tossing ideas around.

 

[an39511]

If you want to hear a BCD536HD steaming online with Alpha Tags check out Cleveland Police Dispatch, Brook Park and SW Suburbs Police and Fire

Yes, I am using the rear audio jack using a modified patch cable.

This test feed will be up until 3PM PST. After that the original equipment is reinstalled.

 

[Dafe1er]

If you want to hear a BCD536HD steaming online with Alpha Tags check out Cleveland Police Dispatch, Brook Park and SW Suburbs Police and Fire

Yes, I am using the rear audio jack using a modified patch cable.

This test feed will be up until 3PM PST. After that the original equipment is reinstalled.

Sounding loud and clear to me. Thanks.

 

[AE7Q]

Don't rush in where angels fear to tread

OK guys, Adding an amplifier inline works!

My understanding of the circuit is that, while an external amplifier may increase the volume to the level desired, there is still the possibility of grounding half of the scanner's audio driver circuit, with consequent possible damage to the scanner.

That can happen if there is ANY ground path from the scanner to the amplifier (eg, through a mutually connected PC). Connecting a USB cable causes a ground path, as someone has reported.

The only safe isolation is a small audio transformer.

There is a warning about this in the Uniden manual, but it is so poorly worded as to be unusable. Instead, it should clearly state that the shaft connection is not, and should not ever be grounded or have a path to the ground of the scanner.

 

[RF23]

My understanding of the circuit is that, while an external amplifier may increase the volume to the level desired, there is still the possibility of grounding half of the scanner's audio driver circuit, with consequent possible damage to the scanner.

That can happen if there is ANY ground path from the scanner to the amplifier (eg, through a mutually connected PC). Connecting a USB cable causes a ground path, as someone has reported.

The only safe isolation is a small audio transformer.

There is a warning about this in the Uniden manual, but it is so poorly worded as to be unusable.

Do you think the "Ground Loop Isolator" sold by Radio Shack would work? I think the bulge in the cord is an audio transformer, but I have not tested it to make for sure.

 

[AE7Q]

Do you think the "Ground Loop Isolator" sold by Radio Shack would work? I think the bulge in the cord is an audio transformer, but I have not tested it to make for sure.

I'm not familiar with that product, but you might consider this instead from Amazon, because it has the proper connector for the scanner:

Amazon.com: PAC Ground Loop Isolator for 3.5 MM Applications: Automotive

At any rate, for less than $20 (either source), it would be worth a try. Whatever you get, check it out with an ohm-meter, to verify that there is no DC path from one side to the other.

 

[RF23]

I'm not familiar with that product, but you might consider this instead from Amazon, because it has the proper connector for the scanner:

Amazon.com: PAC Ground Loop Isolator for 3.5 MM Applications: Automotive

At any rate, for less than $20 (either source), it would be worth a try. Whatever you get, check it out with an ohm-meter, to verify that there is no DC path from one side to the other.

Thank your for this helpful information.

I am going to get the one from Amazon since it does have the proper connections.

Thanks again!

 

[ems170]

According to the manual the unit can not be connected to a Class D amp. I am using Bogen C-100 amps for fire station alerting. These amps are class M. According to Uniden tech support this should work. Can anyone chime in (UpMan), and say yes or no this wont work. I have 7 units to install, and dont want to blow them out.