BCD536HP: Audio Out

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OHIOSCAN

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Know matter what I try I cannot get audio to record. Using a speaker audio out is fine, running patch cord into sound card no audio is received into line-in. All levels are 100%, 536 audio is at 12. Tried internal soundcard and external soundcard. If I swap my 8500 to either sound card works fine. I see no audio settings in 536, in ARC536 the audio is checked and started. Audio files show up but no audio, I basically unplugged working line-in cord from my PSR600 swapped into my 536.

Any Ideas?
Thanks
Mike
 

UPMan

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EXT SP. jack on the back of the scanner is much too big a signal for the sound card. Need to use a line-in converter or just record in the scanner and move the files to your PC, later.
 

OHIOSCAN

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Record

EXT SP. jack on the back of the scanner is much too big a signal for the sound card. Need to use a line-in converter or just record in the scanner and move the files to your PC, later.
How do I set it to record only certain TG's and I am guessing I need to pull the card to get those files that's a bit of a pain. I see nothing in the manual for general recording, REPLAY is great but I need to record multiple TG's over a couple of days in a format that can be converted to mp3

Thanks
 

UPMan

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Press RECORD (F+REPLAY). It records every transmission. If you want to limit it to only certain channels, program those channels into a Favorites list and scan only that (or avoid everything you don't want to record).
 

Mike_G_D

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I'll add to what UpMan said regarding the external speaker jack on the 536 - make sure that the shield of whatever cable you are using is NOT connected to any ground (on the PC or other device - speakers don't matter as long as they are the only thing connected).

See this thread: http://forums.radioreference.com/uniden-owner-tech-support/293521-external-audio-jack-bcd536-2.html.

If you follow that diagram in the last post by me, you could then attach an attenuating patch cord (or some other audio attenuator) to the end of the modified cable (the one in the diagram) and then to your PC audio input (you would need a female-female 1/8 inch phone plug adapter to attache the two cables together); just remember, the ground modified cable goes between the external speaker jack of the radio and the attenuating patch cable goes between the PC side of the first cable and the PC audio input. Then you would have the correct audio and ground connection to the radio as well as speaker-to-line level attenuation.

Or you could build your own adapter that does it all (see attachment).

-Mike
 

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OHIOSCAN

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Thanks I will have to look at trying to piece that together. It's absolutely assine that Uniden would use this setup. Every one of the 6 radio's I own are setup to record into PC's, I am guessing most hobbyist do the same to log traffic. Recording on the 536 is all or nothing and daily write's to the card are going to kill it. My other radio's all offer option for logging specific freqs or TG's, using this setup is going to lead to a lot of pissed of users. Hopefully mine is not damaged I have been plugging in mono & stereo patch cables into multiple sound cards trying to set this up like all my other radios. I see no warnings in the manual regarding the speaker jack.

Thanks for the help, hopefully RS still has the parts
Mike
 

Mike_G_D

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Actually the only thing I would fault Uniden on is not including a line out (aka "Record Out") jack on their new series. I'm sure it was a cost cutting measure and they really figured on the SD record feature and maybe the Siren App (if I understand it correctly) or some such for those who need to stream audio. Otherwise, the external speaker output is a good design albeit intended solely for a speaker and not for any interconnection to any other devices. As a external speaker output, it is fine and provides a good amount of power with decent efficiency. It's just not a good audio interface for device-to-device line level usage. But then, most speaker outputs are NOT designed for that. It's just that, in many cases, one has no other option and has the external speaker output as the only audio output besides a headphone output. The GRE 500/600 series radios have never had a line output. Users of those radios have always had to deal with attenuating a power intensive speaker audio level down to a line or mic level when recording or streaming. But they did not have BTL drivers, admittedly, to deal with in the process (so no major ground issues).

Uniden, in a sense, "spoiled" their users by including, very smartly, a nice line output on their 15 and x96 series radios. Unfortunately, again, I'm guessing for cost cutting reasons, they decided to omit this much used feature on the new series forcing Uniden users who were accustomed to using the "Record Out" jack to now resort to using the speaker output or the headphone output as GRE users had been forced to do. In addition, given the BTL design, it caused great confusion among users when grounding one side of the BTL amp caused issues!

A BTL design is a fine choice and much used among professional land mobile radios. But most of those radios also include line outputs (or, even if they don't, most are installed by trained professionals and the installations are, thereafter, not altered by the users anyway). But BTL outputs without protection do not like to have half of their output shorted to ground when some users unknowingly try to plug a simple grounded sleeve/shield plug into them as would be done when trying to use the output for device connections other than a passive speaker.

It's just an unfortunate oversight on Uniden's part complicated by their choice (actually, for speaker usage a GOOD choice!) of external speaker amplifier design.

But you CAN work around it!

If you try my designs, try the simplest one first, the "direct coupled fixed attenuation" version as that will be the easiest to construct and get parts for. I think the transformer versions should only be tried experimentally by those familiar with basic electronics as I didn't specify an exact part for the isolation transformer and that part may need to be experimentally chosen (though I would think just about any audio isolation transformer SHOULD work, in theory, except for autotransformers). If you need variable attenuation and want to run a speaker at the same time then the direct coupled version with variable attenuation should be fine. Feel free to experiment with the attenuation resistor values to see what works best for you - just understand how voltage dividers work. The values aren't extremely critical.

If you only use it for the 536 you can omit the jumper and related parts and wire it strictly for BTL usage. Also, the switch for ground isolation and choices could be omitted if you don't think you need it (you can just dink with the ground directly if you need to - the switch was put there to allow maximum flexibility when using the adapter among and with different devices and setups).

Feel free to PM me directly if you want to ask me anything about the circuit or construction.

-Mike
 

waynedc

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The issue that I am trying to overcome is using the rear panel EXT SP audio fed into an NCS-3230 audio control panel. In order for me to do this, I have to turn the 536 volume all the way up.

Does anyone have any ideas on a way to feed the audio into this device and have the volume control behave like all the other radios do? The other radios (not 536's) allow the volume to be adjust initially on the radio and that setting is somewhere near the lower end of the volume control rotation...

Thank you,
Wayne
 

OHIOSCAN

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Audio

>
Actually the only thing I would fault Uniden on is not including a line out >
>(aka "Record Out") jack on their new series. I'm sure it was a cost cutting measure and they really figured on

Probable correct on why but the extra cost should not have been deal breaking, maybe a couple of bucks.
Already spending $600, $605 would not of been catastrophic. Recording constantly to these SD cards is going to kill them quick.


But you CAN work around it!

>If you try my designs, try the simplest one first, the "direct coupled fixed attenuation" version as that will >be the easiest to construct and get parts for. I think the transformer versions should only be tried

I have less the basic skills so the direct coupled version is my only option. (gr)


>Feel free to PM me directly if you want to ask me anything about the circuit or construction.

Ok thanks for the help

Mike
 

Mike_G_D

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The issue that I am trying to overcome is using the rear panel EXT SP audio fed into an NCS-3230 audio control panel. In order for me to do this, I have to turn the 536 volume all the way up.

Does anyone have any ideas on a way to feed the audio into this device and have the volume control behave like all the other radios do? The other radios (not 536's) allow the volume to be adjust initially on the radio and that setting is somewhere near the lower end of the volume control rotation...

Thank you,
Wayne
First off, I'd make sure you don't have the ground connected from the rear external speaker connector; see this thread: http://forums.radioreference.com/uniden-owner-tech-support/293521-external-audio-jack-bcd536-2.html.

At least make sure you are connected as in my diagram in my last post on that thread. The BTL amp of the 536 does NOT like to have half its output shunted to ground! I know it seems weird not to connect the "ground" (shield) of the rear external speaker jack but that's the deal - the BTL amp of the 536 essentially takes two standard audio amps and ties them together such that one is connected to the center pin of the phone jack while the other is connected to the sleeve (or "shield") of the phone jack. The ground is connected internally between the two. A passive speaker "sees" an audio signal comprised of the addition of two amplified audio signals - like the absolute value of the difference between -3 and +3 is 6 total on a number line (and not 0 as if you added the two normally).

Here is a picture that I hope will help make things clearer for some:
 

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waynedc

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First off, I'd make sure you don't have the ground connected from the rear external speaker connector; see this thread: http://forums.radioreference.com/uniden-owner-tech-support/293521-external-audio-jack-bcd536-2.html.

Mike_G_D, I did try the cable as stated above. The 536 volume worked correctly but it kept the green audio light constantly lit for the 536 on the NCS-3230 front panel.

The lesser of the two evils for me is the light off until audio is received and having to turn the 536 volume all the way up - so I went back to the unmodified cable. I have ordered and will try a 600ohm audio isolation transformer cable. I will let you know how that goes when received.

Thank you,
Wayne
 

Mike_G_D

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First off, I'd make sure you don't have the ground connected from the rear external speaker connector; see this thread: http://forums.radioreference.com/uniden-owner-tech-support/293521-external-audio-jack-bcd536-2.html.

Mike_G_D, I did try the cable as stated above. The 536 volume worked correctly but it kept the green audio light constantly lit for the 536 on the NCS-3230 front panel.

The lesser of the two evils for me is the light off until audio is received and having to turn the 536 volume all the way up - so I went back to the unmodified cable. I have ordered and will try a 600ohm audio isolation transformer cable. I will let you know how that goes when received.

Thank you,
Wayne
Hmm, don't know a lot about how the NCS-3230 is designed but the busy light might be an indication of some noise on the line which may be outside of human hearing range but still within the range of what the 3230 can interpret as a signal. Since a Class D amp is being used in the 536 this is entirely possible. Some shunt caps on the line may clean this up (try a 4700pF and a 100pF to ground from the audio center conductor and see if that cleans that out, preferably at the radio connection end with as short as possible lead length for the caps). It could also be due to DC on the line in which case a series cap of 1uF or greater would be desired or even just a series 10K resistor (which may help with a little needed extra attenuation too). Otherwise, not sure, did you have the cable shield tied to the radio case ground at the radio end or left floating? The fact that the volume worked well is a very good sign! And I would call the "lesser of two evils" not having one half of the BTL amp grounded so, at least to me, I wouldn't worry about the busy light - again, try the shunt caps and maybe a series 10K resistor.

For my own use, I am working on my own design for a six input scanner radio speaker mixer. It will be agnostic to type of input - it will include its own level attenuated isolation transformers on each line and can handle either single ended or BTL outputs without issue. Just vaporware now but I'm enjoying the design effort (helps keep me sane during an extremely stressful and difficult time for me). I see the NCS-3230 is now discontinued - they seem more focused on professional LMR customers now according to their website and current product line.

-Mike

EDIT: I attached a new diagram which illustrates what I was saying above. The extra shunt resistor (R2) forms a 10:1 voltage divider with the series resistor, R1, for a little extra attenuation. If the level is too low you can change the resistor values or even remove the shunt resistor altogether (but leave the series resistor and shunt caps in).
 

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