BCD996P2 Extension Speaker

[Adavis4]

Hi folks,
No issue, just seeking some tech advice. I have a 996P2- love it. I'm working on a project now where I'm going to be using the scanner in fire tone-out mode. I'm going to run audio out (external speaker jack I suppose?) to an amplifier that will split my single audio out to 2x audio out. One will go to an external speaker (any model recommendations?) and the other will actually go as the input to a current activated relay.

The theory is that when the scanner picks up the necessary tones and alerts, the tiny bit of current in the audio wire will activate the relay which will in turn operate an alarm bell and LED light for a specified period of time. I'm pretty squared away on the relay, but the relay, alarm bell and speaker will be in my garage and for temperature reasons (PA) I don't want my scanner in the garage. This means my audio out cable from the scanner to the relay/bell/light/speaker will be around 30-40'. Any ideas where the right place for the amplifier is? In the middle? Closer to scanner? Closer to speaker?

Final two questiosn: 1) if I connect to the external speaker jack, will I still get audio from the internal speaker on the scanner? Or will it function just like the headphone jack?

2) any impedance concerns with the amp? If so can anyone provide what specs I need for my amp?

Thanks in advance,
Alex

 

[buddrousa]

Come out of the record jack and the audio is fixed. Then you can operate the volume knob for you to listen to without changing the PA settings.

 

[Adavis4]

Thanks! I will definitely use the REC jack.

From what I gather, the BC20 speaker is a 20 watt, 8 ohm speaker. I'm assuming that the output from the scanner amp is 8 ohms as well. Can anyone confirm?

My amp has 47k ohm input impedance, so it should work fine without over working the amp in the scanner. It's got 18 watt, 4-16ohm output, so again should play well with the BC20 speaker.

Does anyone agree or disagree with the above statements?

Also still looking to see where in the run between the scanner and speaker the amp would be best located.

Thanks again!
Alex

 

[n9mxq]

Just make sure the freqs you want to listen to are set to record when you program. Otherwise your speaker will be silent.

Sent from my SM-G950U using Tapatalk

 

[Adavis4]

For anyone that is interested, it looks like i may need to make this a dedicated unit for my alarm bell/light and i will need to use the headpohne jack.

With the group set to record all channels, i get no voltage on the audio out cable when plugged in to the record jack when the radio is active / inactive.

In the ext speaker jack I get 7 volts AC all the time- active and inactive.

in the headphone jack I get 0 volts AC when inactive and 4 volts AC when active - this will be enough to trip my relay.

I'm wondering if the constant voltage out of the external speaker jack is because it's an amplified signal? I also think I read that the external speaker jack is mono, and my cable is most definitely stereo- so i suppose that could be my issue as well.

AD

 

[byndhlptom]

996p2

I believe that the 996P2 has the bridged output amp that the newer units have. You can not reference either speaker lead to ground (you risk killing the output amp). The output is biased by the amp at approximately 1/2 supply voltage on both leads

$.02

 

[Adavis4]

Thanks for the tip!

I'll give it a whirl with a correct mono 3.5mm jack so i'm not shorting either side to ground and see if that works any better. worst case, i'll use the stereo earphone jack.

I'm puzzled as to why i get no voltage out of the REC jack when all channels in the group are set to record. Would be nice to keep the internal speaker free'd up when i'm taking audio out somewhere (REC jack only option for that as far as i know), but it's not critical.

Thanks guys!
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[jonwienke]

You MUST use a stereo plug or you will damage the amp.