BCD536HP Audio Output Problems

[an39511]

I am trying to setup a feed but cannot get the audio output on the BCD536HP to work properly. I have tested both audio outputs and have a very annoying whine that comes through the audio. I have posted two sound files that demonstrate the problem.

Is there anyone that can post a schematic on the output jacks and/or a patch cable that will work with the 536?

Audio from the Headphone Jack
https://dl.dropboxusercontent.com/u/11263151/BCD536HP-FrontSoundJack.mp3


Audio from the Rear Jack
https://dl.dropboxusercontent.com/u/11263151/BCD536HP-RearSoundJack.mp3

 

[kellykeeton]

This is a known issue see the sticky titles headphone jack issues... Likely there will be a recall or something.

 

[kb8rvp]

I am trying to setup a feed but cannot get the audio output on the BCD536HP to work properly. I have tested both audio outputs and have a very annoying whine that comes through the audio. I have posted two sound files that demonstrate the problem.

Is there anyone that can post a schematic on the output jacks and/or a patch cable that will work with the 536?

Audio from the Headphone Jack
https://dl.dropboxusercontent.com/u/11263151/BCD536HP-FrontSoundJack.mp3


Audio from the Rear Jack
https://dl.dropboxusercontent.com/u/11263151/BCD536HP-RearSoundJack.mp3

Upman already posted a message on this yesterday.
http://forums.radioreference.com/uniden-scanners/283740-bcd536hp-headphone-issues.html

Mike

 

[an39511]

I understand there is the headphone issue but I think the problem I am describing is a little different. The headphone jack produces a hissing sound when receiving a transmission. What I am speaking to is a high pitch whine that is in both the headphone jack and the rear jack. The headphone output is a high pitch whine (along with the other noise everyone is writing about) and the rear jack has a lower pitched whine. I want to stream this radio but the noise would be objectionable to those listening.

 

[LIScanner101]

I understand there is the headphone issue but I think the problem I am describing is a little different. The headphone jack produces a hissing sound when receiving a transmission. What I am speaking to is a high pitch whine that is in both the headphone jack and the rear jack. The headphone output is a high pitch whine (along with the other noise everyone is writing about) and the rear jack has a lower pitched whine. I want to stream this radio but the noise would be objectionable to those listening.

That is a new one - the hiss has already been reported and is being addressed, but now there is a "whine" that is being heard...?

Anyone else have this issue?

 

[kellykeeton]

what is your DC power coming from?

 

[an39511]

DC power is coming from the wall wart that came with the radio. I don't think this problem is a fault with the radio itself, but the connection/cable from the radio to the computer.

I have been experimenting with patch cables and have found that using any of my factory made cables do not work with the 536. BTW, these same cables work on other scanners without problems

I have made my own patch cable using a 3.5mm stereo plug (to connect to the line-in of the computer) and a 3.5mm mono (to connect to the 536)

The center leads of the stereo plug are connected together. That lead is connected to a 3.3 k OHM resister and then connected to the center lead of the mono plug. The shields are NOT connected. If I connect the shield of either side the sound is cut way down and that whine I described presents itself. I am not sure why connecting the shields causes problems but I now have a cable that works perfectly. No whine, no hum.

This does NOT correct the original issue with the front head jack but will allow me to start streaming this radio online.

 

[kellykeeton]

what type of speaker are you plugging it into? there was this silly warning about plugging the headphone into a power supply.. or a amplifier.. it was super odd warning.

i assume this audio path as discovered else where is a strange D/A converter use case. and with the other issues that might lead to a recall I assume there is larger problems here.. or simply problems that need to be worked out still.

I think at this time waiting is the best option.

 

[an39511]

what type of speaker are you plugging it into? there was this silly warning about plugging the headphone into a power supply.. or a amplifier.. it was super odd warning.

i assume this audio path as discovered else where is a strange D/A converter use case. and with the other issues that might lead to a recall I assume there is larger problems here.. or simply problems that need to be worked out still.

I think at this time waiting is the best option.

I am not plugging in a speaker but rather plugging into the back of a Dell computer for the purpose of broadcasting the audio online. I suspect it has something to do with ground between the two devices.

The only issue with the 536 that I see is the headphone audio jack. I expect there will be a recall at some point but I would rather have the radio than not. There are plenty of positive things with this radio.

 

[kwd57]

DC power is coming from the wall wart that came with the radio. I don't think this problem is a fault with the radio itself, but the connection/cable from the radio to the computer.

I have been experimenting with patch cables and have found that using any of my factory made cables do not work with the 536. BTW, these same cables work on other scanners without problems

I have made my own patch cable using a 3.5mm stereo plug (to connect to the line-in of the computer) and a 3.5mm mono (to connect to the 536)

The center leads of the stereo plug are connected together. That lead is connected to a 3.3 k OHM resister and then connected to the center lead of the mono plug. The shields are NOT connected. If I connect the shield of either side the sound is cut way down and that whine I described presents itself. I am not sure why connecting the shields causes problems but I now have a cable that works perfectly. No whine, no hum.

This does NOT correct the original issue with the front head jack but will allow me to start streaming this radio online.

To make this easier to explain, on mono cables I have worked with, there is a center wire and the shield, which is the ground side. If the shield is not connected,(which is not only the shield, it is your second wire) you only have one wire connected, which should result in no signal at all. I have been using stereo cables with no problem and see no need for a mono end. Maybe you should post a pic of the cable end connections that you have made. Also, what is the purpose of the 3.3k resistor? Are you trying to lower the output signal?

 

[an39511]

To make this easier to explain, on mono cables I have worked with, there is a center wire and the shield, which is the ground side. If the shield is not connected,(which is not only the shield, it is your second wire) you only have one wire connected, which should result in no signal at all. I have been using stereo cables with no problem and see no need for a mono end. Maybe you should post a pic of the cable end connections that you have made. Also, what is the purpose of the 3.3k resistor? Are you trying to lower the output signal?

I have a standard 3.5mm stereo patch cables that does not work in the rear speaker jack or the front headphone jack. This is the cable I use on my other scanner feed without any problems.

The reason I installed a mono 3.5mm plug is because the jack in the back of the 536 is a mono jack (I think). I agree without the shield(negative) connected there should be no sound but that is NOT the case here. I don't understand it, but it only works correctly without the shield connected. The only other possible path it could take is out of the power jack, into the wall wart and back through the AC line. If that is true then that would mean the audio is not completely isolated from the chassis ground.

 

[kwd57]

I have a standard 3.5mm stereo patch cables that does not work in the rear speaker jack or the front headphone jack. This is the cable I use on my other scanner feed without any problems.

The reason I installed a mono 3.5mm plug is because the jack in the back of the 536 is a mono jack (I think). I agree without the shield(negative) connected there should be no sound but that is NOT the case here. I don't understand it, but it only works correctly without the shield connected. The only other possible path it could take is out of the power jack, into the wall wart and back through the AC line. If that is true then that would mean the audio is not completely isolated from the chassis ground.

I just plugged in a stereo headset in the front and in the back of mine. The front has sound on left and right and the rear is left only. So I guess we can assume the rear is mono. On what you said about the power supply. When you have a dc power supply plugged in the wall the AC and the ground should be completely isolated from each other. There has to be a simple answer to what is going on with your setup. I would stick with factory cables and look more at what you are connected to. One thing you might try is get one of these USB dongle type devices that have line in and line out connections, (not a mic. input, from the front of a PC) and keep it out of the sound card. I have seen alot of PC's that have built in noise. The PC I am using now has its own noise. If I needed my PC for good sound output, I would get some sort of external box.

 

[cpetraglia]

I would try a ground loop isolator. Sometimes they work and sometimes they make it worse. I use a stereo plug with the left and right combined from the head phone output jack. I had a 60Hz hum going on until the isolator was installed. I don't feed a PC but an amplifier for a decent monitor speaker. I cant deal with the scanners speakers. To me, they are about useless.
Nowadays most all power supplies are of the switching type and neither the + or - are grounded. Your PC is grounded. You might try a real ground to your scanner. Be sure to use a DC volt meter between the ground source and the scanner before you hook it up. If you have anything over 1/2 a volt, don't try it. P.S. The shield should always be connected for quality sound.
Good luck

 

[RF23]

I am not plugging in a speaker but rather plugging into the back of a Dell computer for the purpose of broadcasting the audio online. I suspect it has something to do with ground between the two devices.

The only issue with the 536 that I see is the headphone audio jack. I expect there will be a recall at some point but I would rather have the radio than not. There are plenty of positive things with this radio.

According to the 536 manual the Speaker Out is Mono the headphone out however is stereo.

More than likely you may need a mono to stereo adapter to plug into the computer or you may short out the left channel to ground. If you are using a mic input you are also probably going to need a "attenuation" cable like Radio Shack sells or you may get an overload.

You might take your scanner and laptop to the car and use the DC adapter just to see if you get this same problem there too.

The ground isolation loop eliminator that has already been mentioned may be needed too. Radio Shack sells those too.

What application do you plan on using to broadcast with?

 

[FirstClass]

Did you try an attenuating cable?. Sometimes called a dubbing cable.

 

[an39511]

According to the 536 manual the Speaker Out is Mono the headphone out however is stereo.

More than likely you may need a mono to stereo adapter to plug into the computer or you may short out the left channel to ground. If you are using a mic input you are also probably going to need a "attenuation" cable like Radio Shack sells or you may get an overload.

You might take your scanner and laptop to the car and use the DC adapter just to see if you get this same problem there too.

The ground isolation loop eliminator that has already been mentioned may be needed too. Radio Shack sells those too.

What application do you plan on using to broadcast with?

I already have a factory made attenuation cable but that doesn't work on this radio. What I have effectively done is made my own attenuation cable using the 3.3 K resister. The only difference is not connecting up the shield.

I tried grounding the scanner chassis to the PC but that did not fix the problem.

Had the 536 streaming on Broadcastify today for a few hours. The sound is great but only without the shield connected. Go figure.

Using Scannercast for audio and Alpha Tags.

 

[LIScanner101]

The problem is sounding more and more like a ground loop issue. Different grounds being connected together is causing the common/return of the audio circuit to contain a 60Hz or 120Hz component.

 

[RF23]

I already have a factory made attenuation cable but that doesn't work on this radio. What I have effectively done is made my own attenuation cable using the 3.3 K resister. The only difference is not connecting up the shield.

I tried grounding the scanner chassis to the PC but that did not fix the problem.

Had the 536 streaming on Broadcastify today for a few hours. The sound is great but only without the shield connected. Go figure.

Using Scannercast for audio and Alpha Tags.

If you have your laptop on batteries only do you still have the problem?

Are you plugging the computer and scanner into the same UPS or extension cord or wall socket?

Are you using three prong AC plugs outlets/extension cords/UPS?

If you have only two blade AC connections are you keeping the wide blade orientated the same for all electronic items?

I asked about what application you were using because one person has reported here on RR that he is having lack of audio output from his 536 external speaker jack to Scannercast but when he uses the same cables and computer with his 996xt everything works great. In addition, if he plugs in an external speaker into the 536 external speaker jack it sounds nice and strong. I was hoping it might be the lack of optimization of Scannercast for the new radios (some have mentioned this will soon be done) but since yours is sounding good that probably lets that out as a possibility.

So, another strange problem here too!

 

[an39511]

If you have your laptop on batteries only do you still have the problem?

Are you plugging the computer and scanner into the same UPS or extension cord or wall socket?

Are you using three prong AC plugs outlets/extension cords/UPS?

If you have only two blade AC connections are you keeping the wide blade orientated the same for all electronic items?

I asked about what application you were using because one person has reported here on RR that he is having lack of audio output from his 536 external speaker jack to Scannercast but when he uses the same cables and computer with his 996xt everything works great. In addition, if he plugs in an external speaker into the 536 external speaker jack it sounds nice and strong. I was hoping it might be the lack of optimization of Scannercast for the new radios (some have mentioned this will soon be done) but since yours is sounding good that probably lets that out as a possibility.

So, another strange problem here too!

The scanner is plugged into a Dell Optiplex 380. I also tried it on a Dell 8700 with the same problem. All equipment is plugged into a large UPS which is properly grounded.

The audio problem has nothing to do with Scannercast. It is an issue between the computer hardware and the BCD536HP. As you wrote, plugging in other scanners present no issues with audio so I know it is something different with the 536. It really isn't a big deal once I knew what to do to make it work but I suspect others will be running into this issue as more of them try to stream them online.

 

[RF23]

The scanner is plugged into a Dell Optiplex 380. I also tried it on a Dell 8700 with the same problem. All equipment is plugged into a large UPS which is properly grounded.

The audio problem has nothing to do with Scannercast. It is an issue between the computer hardware and the BCD536HP. As you wrote, plugging in other scanners present no issues with audio so I know it is something different with the 536. It really isn't a big deal once I knew what to do to make it work but I suspect others will be running into this issue as more of them try to stream them online.

That certainly sounds reasonable to me too.

Another user has posted here on RR that the audio out of the 536 was very different in quality (a lot of extra filtering apparently involved) compared to the 996XT. I do not know if the extra filtering circuits (if true) could be part of the problem or not.